From: Thomas Brandon [tom@psy.unsw.edu.au] Sent: Friday, August 06, 1999 9:09 AM To: James Newton Subject: Re: 00000004 How to connect an IDE disk to a microcontroller using an 8255 ============================================================= Introduction ============ Some time ago I have dropped that I had connected an IDE harddisk to one of my microcontrollers. This has provoced a response that I had not forseen. Since that day I have received some one to two e-mails a day requesting more details about what I had done. At first I have mailed a more or less cryptic decription of my interface to some of the requesters. That only resulted in more e-mail asking for more details. As it seems some people out there are really interested in how my contraption is made. In this description I will attempt to satify the information-hunger of all you out there who's appetite I seem to have awakened. This interface first came to my mind when I re-read some old, old computer magazines. In one of them, the German magazine called C't there was a short description of how and IDE interface is put together. This is in the November issue of 1990. The article describes an IDE interface for both the PC-XT(!) and the PC-AT. The circuit diagrams of the article indcate that the hardware of an IDE interface is in fact very simple. It is essentially a data bus extension from the PC-AT bus to an IDE device. For a PC the hardware comes down to some bus buffers and some decoding. When a disk is connected as an IDE device the PC-AT still 'sees' the old-type control registers of the ancient MFM disk controller. In the article the entire interface is implemented using simple TTL chips. The main problem in a PC seems to be how to keep the harddisk interface and the floppy interface from colliding on some register addresses. If the IDE interface is implemented based on some controller system this is of course no problem. From a controller point of view an IDE interface could be described as a set of I/O ports. The IDE interface has a 8/16 bits I/O bus, two /CS lines, a /WR and /RD line, three address bits and one interrupt. In this description I assume the most traditional IDE interface. In later IDE interfaces a series of nice so-called PIO modes where added. These PIO modes add things like a ready line, DMA facilities and higher speed data transfers. As you read on you will understand that I only use the so-called PIO mode 0. This is the slowest communication modus on an IDE bus. It is also the easiest one to implement. The data bus on an IDE interface is used mostly for 8-bits transfers. Only the real disk data reads and writes use the 16-bits bus in full width. You COULD even implement an IDE interface with an 8-bits only data bus. That would mean that you use only half the disk capacity (the lower bytes of the 16-bits-wide bus) but that should work. When scanning the net I did find an implementation of an IDE interface for 8-bit controllers. This interface was for a (hope I have this correct..) COCO bus. It was implemented in TTL, just like the magazine's interface. The main idea was that whenever a (16-bits) word was read from the IDE bus the upper 8 bits where stored in a latch. The controller could retrieve them from the latch later. Writing to the IDE bus was implemented in the same manner. The IDE bus read/write cycles where in fact simple bus read and write cycles. At first I was about to copy this design. When thinking about it I thought that this TTL design was too complex for what I wanted to do. You need quite some TTL to implement a 16-bits read/write I/O port in TTL on an 8-bits controller. Hardware description ==================== When implementing a 16-bits I/O port all you need is a bidirectional I/O port and some control bits to generate the /RD, /WR etc... That is when the 8255 came in view. An 8255 has 3 8-bits I/O ports. It can be switched from output to input and back under software control. I used 2 of the 8-bits I/O ports for the data path and use port to generate the IDE control signals. The 74HC04 came into the design later. Once I had the controller and the 8255 strapped together with the IDE connector and a disk I found out that the 8255 has a nasty trait. Whenever you switch the I/O modus of the chip it resets ALL its memory bits. That includes ALL output signals too. For the data bus that is not so much of a problem. The control signals get a real shake when this happens. In particular: The /RESET line of the interface is activated. That makes all control of a disk on this interface impossible (the disk gets a reset at all kinds of odd moments...). I have solved this by simply inverting all the control signals from the 8255 to the IDE bus. When the modus of the 8255 is switched all outputs of the chip go to '0'. That means that all the (low-active) control signals are made inactive by the inversion. That is -in fact- the state where I have them already when I'm about to change the 8255's modus. At this point I would like to present a nice circuit diagram to show what the contraption I have made looks like. Unfortunately I know of no easy way to do that. This beautiful net is a marvel when it comes down to transporting text, graphics is another matter. A GIF picture would do the work; I do not have any means to produce one. Some schematics drawing package could give a good picture; I have no schematics package and I am not sure what package would be universal enough to be usable by everyone. So I am restricted to a more or less cryptic ASCII description of the hardware. Please, the cryptology is out of need, not out of my liking. Well here it comes: 1) The IDE bus pin connections themselves: --------------------------------------- The IDE connector itself is a 40-pins two-row connector: 1 39 odd-numbered pins .................... .................... 2 40 even-numbered pins In an IDE bus this connector is used as follows: pin no: name: function: --------- ------- --------- 1 /RESET Al low signal level on this pin will reset all connected devices 2,19,22 GND ground, interconnect them all and tie to 24,26,30 controller's ground signal 40 3,5,7,9,11 D7..D0 low data bus, 3=D7 .. 17=D0. This part of 13,15,17 the bus is used for the command and parameter transfer. It is also used for the low byte in 16-bits data transfers. 4,6,8,10 D8..D15 high data bus, 4=D8 .. 18=D15. This part 12,14,16,18 of the bus is used only for the 16-bits data transfer. 20 - This pin is usually missing. It is used to prevent mis-connecting the IDE cable. 21 and /IOREADY I do not use or connect to this pin. It is 27 there to slow down a controller when it is going too fast for the bus. I do not have that problem... 23 /WR Write strobe of the bus. 25 /RD Read strobe of the bus. 28 ALE Some relic from the XT time. I do not use it, and I'm not the only one... 31 IRQ Interrupt output from the IDE devices. At this moment I do not use it. This pin could be connected to a controller to generate interrupts when a command is finished. I have an inverter ready for this signal (I need a /IRQ for my controller, an IRQ is of no use to me..) 32 IO16 Used in an AT interface to enable the upper data bus drivers. I do not use this signal. It is redundant anyway, the ATA-3 definition has scrapped it. 34 /PDIAG Master/slave interface on the IDE bus itself. Leave it alone or suffer master/slave communications problems. Not used (or connected to ANYTHING) by me. 35 A0 Addresses of the IDE bus. With these 33 A1 you can select which register of the IDE 36 A2 devices you want to communicate. 37 /CS0 The two /CS signals of the IDE bus. Used 38 /CS1 in combination with the A0 .. A2 to select the register on the IDE device to communicate with. 39 /ACT A low level on this pin indicates that the IDE device is busy. I have connected a LED on this pin. The real busy signal for the controller I get from the IDE status register. Input/Output status of these signals: ------------------------------------- The signals: A0, A1, A2, /CS0, /CS1, /WR, /RD and /RESET are always outputs from the controller to the IDE bus. The signals: IRQ and /ACT are always outputs from the IDE bus to the controller (IRQ can be tri-stated by the IDE device when two devices are connected to the IDE bus.) /ACT can drive a LED (with resistor of course). The signals: D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15 are bi-directional. They are output from the controller to the IDE bus when writing, output from the IDE device to the controller when reading information. 2) The 8255 <-> controller ----------------------- The 8255 is connected to the controller by means of its 8-bit data bus, the A0 and A1 lines and the /CS, /WR and /RD lines. I can not give that much info about this. If in doubt: consult the 8255 data sheet. This part depends as much on the controller you use as anything else. I have the 8255 connected to my controller (HD63B03R1CP, a Hitachi 6803-derivate..) as an I/O port. Perhaps some of you have seen my previous e-mails asking for the pinout of the HD63B03R1CP (52-pins PLCC) chip, well I did find it (Some department of my work had an old Hitachi databook, voila the pinout was there). My address decoding puts the 8255 on address 0500H to 0503H in the controller's memory map. That may help if you decide to try to make sense of my software listing. On this point you are on your own as to the how to connect a 8255 to your controller. 3) 8255 <-> IDE connector ---------------------- I have used the 8255's port A to generate the IDE bus control signals. Some of these control signals pass through an inverter before I connected them to the IDE connector itself. All of these signals are always used as output from the 8255 to the IDE bus. When a control signal is inverted the 8255 pin is connected to one of the inputs of the 74HC04 and the (corresponding) output of the 74HC04 is connected to the IDE bus connector. The ports B and C are used as the 16-bits data bus. There are no special things in this, it's just a simple interconnection of the 8255 I/O pins to the D0..D15 pins of the IDE connector. I have connected this as follows: --------------------------------- PA.7 --> inverter --> IDE bus /RESET PA.6 --> inverter --> IDE bus /RD PA.5 --> inverter --> IDE bus /WR PA.4 --> inverter --> IDE bus /CS1 PA.3 --> inverter --> IDE bus /CS0 PA.2 --> IDE bus A2 PA.1 --> IDE bus A1 PA.0 --> IDE bus A0 PB.7 <--> IDE bus D7 PB.6 <--> IDE bus D6 PB.5 <--> IDE bus D5 PB.4 <--> IDE bus D4 PB.3 <--> IDE bus D3 PB.2 <--> IDE bus D2 PB.1 <--> IDE bus D1 PB.0 <--> IDE bus D0 PC.7 <--> IDE bus D15 PC.6 <--> IDE bus D14 PC.5 <--> IDE bus D13 PC.4 <--> IDE bus D12 PC.3 <--> IDE bus D11 PC.2 <--> IDE bus D10 PC.1 <--> IDE bus D9 PC.0 <--> IDE bus D8 I have put a 10 KOhm pull-down resistor from the IDE bus IRQ to ground. The IDE IRQ signal is also connected to the input of the (one-remaining) inverter. The output of the inverter is connected to the controller's /IRQ input. As you can see, I do have the hardware for interrupts here, I do not use it. I tried to use it, but got unexplained errors (I probably did something wrong, I have not yet found what).. |\ IDE IRQ o-----+----+ >o--------o CPU's /IRQ | |/ +++ | | | | 10 KOhm +++ | | -+- GND /// The IDE /ACT signal is connected to a 330 Ohm resistor, the other end of the resistor is connected to a LED, the other end of the LED is connected to the +5 Volts. This gives a nice LED indication of when I'm using the disk. This is -as far as I know- the same hardware a PC uses to produce the disk busy LED you may find on the front of a PC box. 330 Ohm +-------+ LED IDE /ACT o-----+ +------|<-----o +5 Volts +-------+ So much about the hardware of the IDE interface. I hope that is all clear now. If I have been less than clear, please ask. If I have made mistakes, please complain (I said complain, NOT FLAME!!!). IDE read/write and register description ======================================= The IDE device appears to the IDE bus as a set of regsiters. The register selection is done with the /CS0, CS1 and A0, A1, A2 lines. Reading/writing is done with the /RD and /WR signals. I have used the 8255 port A signals to make read/write cycles on the IDE bus. What I do is the following: read cycle: ----------- 1) put the port B and C of the 8255 in input modus. 2) set an address and /CS0 and /CS1 signal on the port A of the 8255. 3) activate the /RD of the IDE bus by setting the equivalent bit in the port A of the 8255. 4) read the data from port B (and C) of the 8255. 5) deactivate the /RD signal on the IDE bus by resetting the equivalent bit of port A of the 8255. write cycle: ----------- 1) put the port B and C of the 8255 in output modus. 2) set an address and /CS0 and /CS1 signal on the port A of the 8255. 3) set a data word (or byte) on port B (and C) of the 8255. 4) activate the /WR of the IDE bus by setting the equivalent bit in the port A of the 8255. 5) deactivate the /WR signal on the IDE bus by resetting the equivalent bit of port A of the 8255. The only difference between 8 bits and 16 bits transfers is the following: - In an 8-bit transfer I use only the port B of the 8255 for data transfer. When writing I put data only on the lower byte of the IDE bus; the upper byte is ignored anyway by the IDE device. When reading I read only port B of the 8255; I never even bother to look at the upper byte. - In an 16-bit transfer I read/write to both the upper and the lower byte of the IDE bus; thus using both port B and port C. The IDE device appears as the following registers: -------------------------------------------------- /CS0=0, /CS1=1, A2=A1=A0=0: data I/O register (16-bits) This is the data I/O register. This is in fact the only 16-bits wide register of the entire IDE interface. It is used for all data block transfers from and to the IDE device. /CS0=0, /CS1=1, A2..A0=001B: This is the error information register when read; the write precompensation register when written. I have never bothered with the write precompensation at all, I only read this register when an error is indicated in the IDE status register (see below for the IDE status register). /CS0=0, /CS1=1, A2..A0=010B: Sector counter register. This register could be used to make multi-sector transfers. You'd have to write the number of sectors to transfer in this register. I use one-sector only transfers; So I'll only write 01H into this register. I do use this register to pass the parameter the timeout for idle modus command via this register. /CS0=0, /CS1=1, A2..A0=011B: Start sector register. This register holds the start sector of the current track to start reading/ writing to. For each transfer I write the start sector in this register. For some fancy reason the sector count starts at 1 and runs up to 256, so writing 00H results in sector number 256. Why that is done is a mystery to me, all other counting in the IDE interface starts at 0..... /CS0=0, /CS1=1, A2..A0=100B: Low byte of the cylinder number. This register holds low byte of the cylinder number for a disk transfer. /CS0=0, /CS1=1, A2..A0=101B: High two bits of the cylinder number. The traditional IDE interface allows only cylinder numbers in the range 0..1023. This register gets the two upper bits of this number. I write the cylinder number's upper two bits into this register before each transfer. /CS0=0, /CS1=1, A2..A0=110B: Head and device select register. The bits 3..0 of this register hold the head number (0..15) for a transfer. The bit 4 is to be written 0 for access to the IDE master device, 1 for access to the IDE slave device. The bits 7..5 are fixed at 101B in the traditional interface. /CS0=0, /CS1=1, A2..A0=111B: command/status register. When written the IDE device regards the data you write to this register as a command. When read you get the status of the IDE device. Reading his register also clears any interrupts from the IDE device to the controller. /CS0=1, /CS1=0, A2..A0=110B: 2nd status register/interrupt and reset register. When read this register gives you the same status byte as the primary (/CS0=0, /CS1=1, A2..A0=111B) status register. The only difference is that reading this register does not clear the interrupt from the IDE device when read. When written you can enable/disable the interrupts the IDE device generates; Also you can give a software reset to the IDE device. /CS0=1, /CS1=0, A2..A0=111B: active status of the IDE device. In this register (read-only) you can find out if the IDE master or slave is currently active and find the currently selected head number. In a PC environment you can also find out if the floppy is currently in the drive. I have not used this register yet. Some of these registers have bitwise meanings. I'll elaborate on that here: head and device register: ------------------------- A write register that sets the master/slave selection and the head number. bits 3..0: head number [0..15] bit 4 : master/slave select: 0=master,1=slave bits 7..5: fixed at 101B. This is in fact the bytes/sector coding. In old (MFM) controllers you could specify if you wanted 128,256,512 or 1024 bytes/sector. In the IDE world only 512 bytes/sector is supported. This bit pattern is a relic from the MFM controllers age. The bit 6 of this pattern could in fact be used to access a disk in LBA modus. Status register: ---------------- Both the primary and secondary status register use the same bit coding. The register is a read register. bit 0 : error bit. If this bit is set then an error has occurred while executing the latest command. The error status itself is to be found in the error register. bit 1 : index pulse. Each revolution of the disk this bit is pulsed to '1' once. I have never looked at this bit, I do not even know if that really happens. bit 2 : ECC bit. if this bit is set then an ECC correction on the data was executed. I ignore this bit. bit 3 : DRQ bit. If this bit is set then the disk either wants data (disk write) or has data for you (disk read). bit 4 : SKC bit. Indicates that a seek has been executed with success. I ignore this bit. bit 5 : WFT bit. indicates a write error has happened. I do not know what to do with this bit here and now. I've never seen it go active. bit 6 : RDY bit. indicates that the disk has finished its power-up. Wait for this bit to be active before doing anything (execpt reset) with the disk. I once ignored this bit and was rewarded with a completely unusable disk. bit 7 : BSY bit. This bit is set when the disk is doing something for you. You have to wait for this bit to clear before you can start giving orders to the disk. interrupt and reset register: ----------------------------- This register has only two bits that do something (that I know of). It is a write register. bit 1 : IRQ enable. If this bit is '0' the disk will give and IRQ when it has finished executing a command. When it is '1' the disk will not generate interrupts. bit 2 : RESET bit. If you pulse this bit to '1' the disk will execute a software reset. The bit is normally '0'. I do not use it because I have full software control of the hardware /RESET line. Active status register: ----------------------- This is a read register. I have -up till now- ignored this register. I have only one IDE device (a disk) on my contraption. bit 0 : master active. If this bit is set then the master IDE device is active. bit 1 : slave active. If this bit is set then the slave IDE device is active. bits 5..2: complement of the currently active disk head. bit 6 : write bit. This bit is set when the device is writing. bit 7 : in a PC environment this bit indicates if a floppy is present in the floppy drive. Here it has no meaning. error register: --------------- The error register indicates what went wrong when a command execution results in an error. The fact that an error has occurred is indicated in the status register, the explanation is given in the error register. This is a read register. bit 0 : AMNF bit. Indicates that an address mark was not found. What this means I not sure of. I have never seen this happen. bit 1 : TK0NF bit. When this bit is set the drive was not able to find track 0 of the device. I think you will have to throw away the disk if this happens. bit 2 : ABRT bit. This bit is set when you have given an indecent command to the disk. Mostly wrong parameters (wrong head number etc..) cause the disk to respond with error flag in the status bit set and the ABRT bit set. I have gotten this error a lot when I tried to run the disk with interrupts. Something MUST have been wrong with my interface program. I have not (yet) found what. bit 3 : MCR bit. indicated that a media change was requested. What that means I do not know. I've ignored this bit till now. bit 4 : IDNF bit. Means that a sector ID was not found. I have never seen this happen, I guess it means that you've requested a sector that is not there. bit 5 : MC bit. Indicates that the media has been changed. I ignore this bit. bit 6 : UNC bit. Indicates that an uncorrectable data error happened. Some read or write errors could provoce this. I have never seen it happen. bit 7 : reserved. Note: I have these registers descriptions from two sources: 1) The C't magazine I mentioned before. It's in German, not very complete (the error register description is missing) and very old. It does have a hardware description of and IDE interface however.... 2) The document X3T10/2008D: Information Technology- AT Attachment-3 Interface (ATA-3), Working draft. This latter document gives an exhaustive overview of the IDE interface. It states more details of the IDE interface than I can ever hope to include in this short description. It does however have one disadvantage: it's BIG. I found the document on the net (on the Western Digital homepage) in the form of an .exe file. When you run this file on a PC you are rewarded with a bigger-than-1 Mbytes .DOC file. That is a Word document. When you print (Wondows-95 has a Word viewer/printer application) it you get a nearly-200-pages paper. If you want to get into the IDE interface seriously I recommend you print this thing. I hope the description I have given here will allow those that do not have a laser printer and a fast internet link available to get to grips with the IDE bus. Intermezzo: Disk size limitations on the IDE bus and LBA modus ----------- In the PC world there has been (and still is) a lot of discussion about 'limits' in the disk interface. At first (MSDOS versions till 3.3) the disk interface was not able to access more than 32MB on one volume. That was a limitation of the MSDOS file system rather than of the disk interface. The same DOS version that was unable to access bigger partitions than 32MB *WAS* able to access 650MB CDROMs. The limit came from the fact that each disk sector (512 bytes) was registered in the FAT in a 16-bits word. The total partition size was limited by the fact that only 65536 sectors could be addressed. The partition size was thus limited to 65536 x 512 bytes = 32 MBytes. Later -as the disks became larger- the disk interface itself ran into its limits. The interface I describe here has room for 16 heads, 256 sectors per track and only 1024 cylinders. With the standard sector size of 512 bytes that leaves you a maximum disk size of 16 x 256 x 1024 x 512 = 2048 MBytes. That is a real limitation of the IDE interface as I decribe it here. It can not access more than some 2 GBytes of disk space. This was overcome by introducing the so-called LBA modus. In LBA modus the sectors are simply numbered from 0 to -big-. The lowest byte of the LBA sector number is written into the sector number register, the middle 16 bits of the LBA sector number are written in the cylinder number registers (low and high, all 16 bits are used). The highest 4 bits of the LBA sector number are written in the head and device register. That gives you 28 bits of LBA sector number. The sector size was again fixed at 512bytes, so in LBA modus you have access to: 2^28 x 512 = 1.37 E 11 (some 137.4 gigabytes) of disk space. This LBA modus has been made mandatory for all new disks (in the ATA-3 spec.) That should keep the disk makers busy for some while to come... If you want to connect a disk larger than 2 GBytes to this IDE interface you too will have to use the LBA modus. How to do that: the bit 6 of the head and device register is set to indicate that LBA modus is used (the fixed pattern of 101B in the bits 7..5 of the head and device register is to be changed into 111B). All other manipulation of the IDE interface is the same for Sector/Head/Cylinder modus and LBA modus. All other limits in te MSDOS/Windows-whatever disk interface must be due to the BIOS implementation or the file system used. I can find no reason in the IDE definition for 512 MB limits or 8 GB limits at all. End of intermezzo ----------------- IDE registers usage =================== Ok, now you know what registers the IDE system uses. Next question: How to use them? I do not pretend I have tried every possibility with these registers. As I stated before I have restricted myself to reading/writing data blocks to/from the disk. What to do for that is in fact fairly simple: 1) Before doing anything with a device you have to wait till it indicates that it is ready (RDY bit in the status register) 2) Next you load the parameters of a command into the appropriate registers. For read/write commands that comes down to writing the cylinder/head/sector numbers into the registers. 3) You issue a read or write command. 4) You wait till the device signals that it is ready for data transfer (DRQ in the status register). 5) Feed the device data (for write) or get the data from the device (for read). In case of a write you could wait for the operation to complete and read the status register to find out what has become of your data. 6) Finish!! That's all folks! The IDE interface is a surprisingly simple thing to get to work. If only I had an IDE disk and this kind of information when I was still programming my MSX-computer I'd have had a harddisk connected to it in no time. IDE commands ============ What has been missing in this description till now is the command set. I do not think I can describe the complete command set here. The ATA-3 document is a better source for that than I can give here (All I would be doing is re-entering the ATA-3 document; I have neither the time nor any liking for that). The most usable commands I do intend to describe. Mind: When giving a command you first have to wait for device ready, next put the command parameters in the registers and only then can you give a command (by writing a command byte to the command register). The disk will start executing the command right after you've written the command into the command register. IDE command: Description: ------------ ------------ 1XH recalibrate the disk. NB: 1XH means that the lower nibble of the command byte is a don't care. All commands 10H..1FH will result in a recalibrate disk command being executed. This command has no parameters. You simply write the command code to the command register and wait for ready status to become active again. 20H Read sector with retry. NB: 21H = read sector without retry. For this command you have to load the complete circus of cylinder/head/sector first. When the command completes (DRQ goes active) you can read 256 words (16-bits) from the disk's data register. 30H Write sector (with retry; 31H = without retry). Here too you have to load cylinder/head/sector. Then wait for DRQ to become active. Feed the disk 256 words of data in the data register. Next the disk starts writing. When BSY goes not active you can read the status from the status register. 7XH Seek. This normally does nothing on modern IDE drives. Modern drives do not position the head if you do not command a read or write. ECH Identify drive. This command prepares a buffer (256 words) with information about the drive. If you want the details either look closely at the interface program I will add at the end of this description or get the ATA-3 document. To use it: simply give the command, wait for DRQ and read the 256 words from the drive. I have found that the modern drives I used give nice information about number of heads,sectors,cylinders etc... One of the disks I tried (a Miniscribe 8051A) gave wrong answers in this buffer. The disk is actually a 4 heads/28 sectors disk. It should be used in a translated modus with 5 heads/17 sectors. In the ident drive response it reported as 4 heads/28 sectors and it will NOT work in that modus. Two other disks (a Quantum 127 MB disk and a Western Digital 212 MB disk) report nicely. If not for the Miniscribe I would use the parameters reported to auto-config the interface to match the disk configuration. E0H Spins down the drive at once. No parameters. My Miniscribe 8051A does not respond to this command, the other disks do execute this command. E1H Spins up the drive again. Same remarks as E0H command. E2H and E3H Auto-power-down the disk. Write in the sector count register the time (5 seconds units) of non-activity after which the disk will spin-down. Write the command to the command register and the disk is set in an auto-power-save modus. The disk will automatically spin-up again when you issue read/write commands. E2H will spin-down, E3H will keep the disk spinning after the command has been given. Example: write 10H in the sector count register, give command E2H and the disk will spin-down after 80 seconds of non-activity. BTW: You can use this command easily on a PC disk too. The harddisk of the computer I am working on now gets this exact command at boot. That saves a lot of noise when I'm typeing long stories like this one. F2H and F3H The same as E2H and E3H, only the unit in the sector count register is interpreted as 0.1 sec units. I have not tried this command. Ithink it will work (the E0H/E1H/E2H/E3H commands work, why should this one not work?) Two-devices considerations ========================== The IDE bus is intended for two devices. A master and a slave device. I have not tried anything myself, but the descriptions indicate that it is in fact very simple to connect two devices to the IDE bus. All you have to do is: 1) Configure the master/slave jumpers of the devices. 2) Select a device before you start giving commands to the devices. The head and device register has the bit you need to switch from one device to another. You have to write the bit to either 0 for master or 1 for slave and start controlling the other device. Mind: BOTH devices will get their registers WRITTEN. Any data or register READ will come from the selected device. ONLY the selected device will execute commands. Conclusions and ravings ======================= ravings: -------- This description should be about what you need to connect an IDE disk to any controller. The only thing I have left out are my unsuccessfull experiments with the interrupt. What happened there is that I enabled the interrupt, made an interrupt handler that simply read the status register (to get the interrupt to disappear) and re-scheduled the disk interface task. I was rewarded with occasional errors. Some of the read requests got an ABRT error. I do not yet know what I did wrong. I can not have been far off the mark, because most of the commands where executed without comment from the disk. I do intend to try the interrupt modus again later. I theory the interrupt modus should give me a slightly bigger data rate. I have found data rates in the order of 32 KBytes per seccond when I was using interrupts. About interrupts: When you want to use the interrupt mechanism all you have to do is enable the interrupt modus of the interface by clearing the interrupt disable bit in the reset and interrupt register. The disk will generate an interrupts as soon as it has completed a command. That means that it will generate an interrupt when it has read a sector from disk (as soon as DRQ gets active) or when it has finished writing a sector to disk. I am not sure about the other commands, but the description says that the disk will generate an interrupt upon the completion of each command. About the data rate. This IDE interface will never win any award for its speed. It is in one word slow. I get data transfer rates in the order of 25 KBytes per seccond. I spend most of the time reading/writing data words from/to the disk on a word-by-word basis under software control. On the other hand, my controller has a total (RAM) memory of 24 KBytes. With the current interface I can dump the complete memory to disk in less than one seccond. That in itself makes me think that for this application the low speed is not so much of an issue. About the future. I think I will give interrupt modus another try. Not because it gives me a fantastic data rate, I just can't stand it that it does not want to work good. I am thinking about a proper file system to put on the disk. That will enable me to access the disk in a more normal way that the current 'sea of sectors' approach I use now. A FAT filesystem looks like an absolute horror when combined with a controller, so I'll have to either find something that looks good to me or strap something together myself. I think I will give the ATAPI command set a try. I have just found and printed the 'SFF committee specification of ATA Packet Interface for CDROMs' (SFF-8020i) document. That document gives a description of how to control an ATAPI CDROM via the IDE bus. On the other hand: I would really not know what to begin with a CDROM connected to a microcontroller. But what the heck, I have no really good idea what to do with a microcontroller with a 40MB harddisk connected..... I have seen occasional questions in this mailing list about how to control a CDROM via its backside connector: I think this IDE interface with an ATAPI piggy-back software could just do the work. Till now I've been concentrating on only one side of the interface. The IDE interface is in fact no more than a ready-decoded, buffered interface of a (mostly-PC) hardware system. I could in fact connect god-knows-what at the other end. I have an interrupt, DMA and I/O available, what else could you ask for? A disk or CDROM is only one of the less inspired devices you can connect to an IDE interface. Given the fact that modern PC-motherboards have two IDE interfaces aboard I can think of some nice things I'd like to connect to them. How about some 8 parallel input/output ports, how about a data aquisition system? Lately I have been able to get a C-mos version of the 8255. My controller system is quite low-power (10 mA for the entire thing). I did not feel good about the IDE extension with a 8255 that used some 80 mA all by itself. The controller system with the D71055C (a C-mos NEC version of the 8255) has gone down to its normal -about 10 mA- power usage. the change from N-mos 8255 to C-mos D71055C has had no other noticable effects than a lower power usage. Even when I have no disk connected to this contraption it delivers me three 8-bits I/O ports. I am thinking about what other things I could connect to that. conclusions: ------------ As you can see it is far from difficult to connect an IDE disk to some computer. My implementation with a 8255 and an inverter chip may not be the fastest thing on earth, it works, it's simple and may be usable for many applications where a controller with a large backup store could save the day. I'll wrap this up with a case-study: The software I use on my 63B03 controller to control the IDE bus. I hope it can clarify any points I have not covered in this description. I know this software to work, I hope it can give someone inspiration to do something similar on some controller system somewhere. Appendix: ========= The software I use to control a single IDE harddisk using a 63B03 controller system and a 8255/74HC04 IDE interface. Notes: ------ The interface program has been made on a 63B03 controller in assembly code. The 63B03 code is nearly 6800 code. If in doubt, consult some source of 6800 or 6803 or 63B03 instructions. The source of the interface program is of course the most complete description of how to program this interface, but certainly not the most un-cryptic description. I try to program without any 'dirty tricks' but who knows.... This interface program makes sporadic use of the underlying 63B03 real-time scheduler. If you see a 'jsr Sys' somewhere that is where I called the scheduler to do something for me. As far as I can see I only use Sys to produce a 10-ms delay. I have left the code of the scheduler itself out. Not beacuse it is anything but public domain, but beacuse it is another 150 KBytes of source file. This description is long enough as it stands here. The scheduler is not really needed, so I left it out. If you are interested in the scheduler as such, drop me a line (the address is a little up in the text). The IDE interface software as such I hereby donate to the public domain. Use it as pleases you. Change it when you think it is wrong, suffer the consequences if you make mistakes. I do not take responsibility if you blow up harddisks, interface hardware or if anything goes wrong when you use it. I have found it to work on my system and, so sorry, that is all the guarantee I can give you about it. >>>>>>>>>>>>>>>>>>>>>>>> 63B03 assembly listing <<<<<<<<<<<<<<<<<<< 0000 |Begin---------------------------------------------------------- 0000 | 0000 | Disk interface task for the 63B03 system 0000 | 0000 | Update history: 0000 | --------------- 0000 | 02-02-1998 : Started with the thing. The hardware has been 0000 | finished today. All seems to work. Now I need 0000 | software to get some life into it. 0000 | 0000 | 05-02-1998 : Hit a bloody trick of the 8255: When you change 0000 | the modus byte ALL outputs are set to 0. I now 0000 | know why nobody wants to use this bugger. The 0000 | solution for this shit is easy: I plan to put an 0000 | inverter in all the control lines. The following 0000 | lines will be inverted: 0000 | /CS0, /CS1, /IORD, /IOW, /RES, IRQ (the latter 0000 | for the 63B03, it has a /IRQ input).. 0000 | This is the software change needed to make things 0000 | work again... 0000 | 0000 | 06-02-1998 : Hardware change done, disk reset works 0000 | Started testing the disk interface functions. 0000 | The recalibrate command works too, the stop 0000 | disk/start disk functions seem to be not 0000 | present in this 40 MB disk. I also made a LBA 0000 | routine, I can now access the disk as a set of 0000 | sequential blocks, without counting heads etc.. 0000 | It seems the PC hardware starts counting sectors 0000 | starting at 1 (WHY???), all other numbers start 0000 | at 0... 0000 | 0000 | My disk (about 40 MB) tells me it has 0000 | 980 cyls, 5 heads, 17 secs/track. In fact it does 0000 | tell me different numbers, only the label 0000 | indicates that it has been translated... 0000 | 0000 | At this moment I only support disk block read 0000 | and disk block write. I want to make some file- 0000 | system too. Besides, this thing works code-bound. 0000 | I want to start using interrupts too... 0000 | 0000 | 08-02-1998 : /IRQ hardware made ok. The disk can now generate 0000 | interrupts. These will come into the system via 0000 | the CPU's /IRQ signal. I even crashed the system 0000 | by giving /IRQ's with no handler in place... 0000 | Start making the disk software /IRQ-driven. 0000 | 0000 | 10-02-1998 : Changed the interrupt generation/detection 0000 | software Found one nasty bug in the interrupt 0000 | usage as I did it: I first gave a disk reset on 0000 | the IDE bus, then started giving commends right 0000 | away. On this ONE occasion I do NOT have the 0000 | disk's interrupt facility available, the disk is 0000 | still executing its internal reset. I have to 0000 | wait for ready there, THEN start issuing 0000 | commands... Also set the bus control signals to 0000 | output BEFORE I start using the bus at all... Now 0000 | the interrupt mechanism works like the beauty it 0000 | is... 0000 | 0000 | 11-02-1998 : Cleaned up the data transfer code. The disk I/O 0000 | was very slow due to very systematic code. 0000 | ReadWord/WriteWord code substituted in the 0000 | ReadBlock/WriteBlock code. Routines ReadWord/ 0000 | WriteWord removed from the code. There was an 0000 | error in the writeword routine, I've removed it. 0000 | 0000 | 15-02-1998 : I have given up about the interrupt-driven disk 0000 | control. It KEEPS on giving unexplained errors. 0000 | Does NOT want to work independently of the disk 0000 | type and is a general pain in the ass. What 0000 | exactly goes wrong I have no idea about. I now 0000 | use the scheduler's delay routines to get ready 0000 | status from the disk and that works fine. Both 0000 | the 40 MB disk and the 127 MB disk run like the 0000 | sunshine in this modus. The non-interrupt modus 0000 | does in fact not make any significant differenct 0000 | for the transfer speed. I dropped from 32 KB/s to 0000 | 25 KB/s. That is very acceptable for this 0000 | microcontroller. The controller is in this modus 0000 | a lot slower than the disk.... 0000 | 0000 | I'm now going to set the thing up for the 127 MB 0000 | disk with proper track/head numbers. Works ok 0000 | too. 0000 | 0000 | Next test is with the 212 MB disk. I have to take 0000 | care that I stay below track 600 for this disk, 0000 | tracks 630 .. 660 are bad... Sunshine again.. 0000 | 0000 | 16-02-1998 : Made Identify working. It now dumps a nice 0000 | display of what the disk can do. My antique 42MB 0000 | disk gives only half an answer (and a wrong one 0000 | as well, it does NOT tell about the 5 heads,17 0000 | sectors translation it does..) but the other ones 0000 | like this ident command/display a lot. Also 0000 | shifted the buffers in memory a bit. I now want 0000 | to start writing to the disk (till now I have 0000 | only been reading...). 0000 | Ok, I really messed up the data on my 42 MB disk, 0000 | but it DOES write as well as read. I get back 0000 | what I have written, so far, so good. Now I have 0000 | to make: 0000 | 0000 | 1) A proper disk I/O task. That means that I have 0000 | to implement some way of communicating with 0000 | the disk I/O task. signals? I REALLY would 0000 | like to use some sort of mailbox mechanism. 0000 | For that I will have to extend my scheduler. 0000 | 0000 | 2) some sort of file-system. I am already 0000 | contemplating a MFS (Microcontroller File 0000 | System) for some time now. It's about time to 0000 | start working on one.. 0000 | 0000 | 18-02-1998 : Started making task # 0E into a disk monitor. 0000 | 0000 |End------------------------------------------------------------ 0000 * START INCLUDE * incl "debug.inc" | use all debugger routines etc.. 0000 |------------------------------------------------ 0000 | include file for the 63B03 debugger 0000 | file : debug.inc 0000 |------------------------------------------------ 0000 0000 |------------------------------------------------ 0000 | defines for the 63B03 internal I/O 0000 |------------------------------------------------ 0000 | 0000 = 0000 DdrP1 equ $0000 | DDR Port 1 0000 = 0001 DdrP2 equ $0001 | DDR Port 2 0000 = 0002 DataP1 equ $0002 | Data Port1 0000 = 0003 DataP2 equ $0003 | Data Port 2 0000 = 0008 Tcon equ $0008 | Timer Control 0000 = 0009 THigh equ $0009 | Timer high byte 0000 = 000A TLow equ $000A | Timer low byte 0000 = 0009 Timer equ $0009 | Timer for word access 0000 = 000B TComH equ $000B | Timer output compare high byte 0000 = 000C TComL equ $000C | Timer output compare low byte 0000 = 000B TCom equ $000B | Timer output compare word access 0000 = 000D TCapH equ $000D | Timer input capture high byte 0000 = 000E TCapL equ $000E | Timer input capture low byte 0000 = 000D TCap equ $000D | Timer input capture word address 0000 = 0010 ModBaud equ $0010 | Sio baudrate and mode control register 0000 = 0011 SioCon equ $0011 | Sio control register 0000 = 0012 SioRec equ $0012 | Sio receive register 0000 = 0013 SioSnd equ $0013 | Sio transmit register 0000 = 0014 RamCon equ $0014 | Ram Control register 0000 | 0000 |------------------------------------------------ 0000 | Some of the Interrupts I do not use here and now. 0000 |------------------------------------------------ 0000 | 0000 = 7FF0 ToiInt equ $7FF0 | vector them to RAM 0000 = 7FF4 IciInt equ $7FF4 | 0000 = 7FF8 IrqInt equ $7FF8 | 0000 = 7FFC NMIInt equ $7FFC | 0000 | 0000 |------------------------------------------------ 0000 | The bytes SioByte and SioStat are used as 0000 | follows: 0000 | SioByte is the latest received byte from the Sio 0000 | SioStat indicates the status of the sio with the 0000 | following bits: 0000 | 0000 = 0080 SioEcho equ %10000000 | echo modus ON 0000 = 0040 SioRaw equ %01000000 | RAW input modus 0000 = 0020 SioInAv equ %00100000 | input received 0000 = 0010 SioEsc equ %00010000 | Run modus interrupt enable 0000 | 0000 |------------------------------------------------- 0000 | constans etc.. for the program 0000 |------------------------------------------------- 0000 | 0000 = 000A lf equ $0A | <LF> 0000 = 000D cr equ $0D | <CR> 0000 = 0000 eom equ $00 | end of message 0000 | 0000 |------------------------------------------------- 0000 | a few constants for single-step control 0000 |------------------------------------------------- 0000 | 0000 = 003F swic equ $3F | opcode for swi 0000 = 4000 start equ $4000 | default start adres voor single-step 0000 = FFFF nil equ $FFFF | nil pointer 0000 | 0000 |--------------------- 0000 | System entry points 0000 |--------------------- 0000 | 0000 = F000 SndData equ $F000 | send a data byte to the sio 0000 = F003 RecSio equ $F003 | receive a (raw) data byte from the sio 0000 = F006 RecData equ $F006 | receive a (coocked) data byte from the sio 0000 = F009 SndStr equ $F009 | send (X) ASCIZ string to the sio 0000 = F00C Prompt equ $F00C | give a prompt 0000 = F00F NewLine equ $F00F | print new line 0000 = F012 WaitRet equ $F012 | wait for a return 0000 = F015 RecHex equ $F015 | receive hex byte from the sio 0000 = F018 RecHex1 equ $F018 | receive non-space byte from the sio 0000 = F01B ConvHex equ $F01B | convert byte from ASCII -> hex 0000 = F01E SndHex equ $F01E | send byte as two hex ASCII chars 0000 = F021 SndHex1 equ $F021 | no-space send byte asc ASCII chars 0000 = F024 SndHDig equ $F024 | send one hex digit 0000 = F027 RecAdr equ $F027 | receive starta and enda from sio 0000 = F02A RecAdr1 equ $F02A | receive enda from the sio 0000 = F02D CI equ $F02D | Command Interpreter 0000 = F030 GetName equ $F030 | get name string pointer for address 0000 = F033 Go equ $F033 | edit memory 0000 = F039 Edit equ $F039 | go start at some address 0000 = F03F HexFile equ $F03F | download hexfile 0000 = F042 ModReg equ $F042 | modify single-step registers 0000 = F045 Ver equ $F045 | print version info 0000 = F048 Help equ $F048 | give help message 0000 = F04B NoCmd equ $F04B | No Command found 0000 = F04E Adr equ $F04E | set start Adres 0000 = F051 Break equ $F051 | set breakpoint address 0000 = F054 Cont equ $F054 | Continue till address 0000 = F057 JmpSub equ $F057 | -> JmpSub 0000 = F05A Step equ $F05A | -> single-step 0000 = F05D GoBrks equ $F05D | -> GoBreaks 0000 = F060 Trap equ $F060 | -> Trap 0000 = F063 Stop equ $F063 | -> Stop 0000 = F066 RunInt equ $F066 | -> RunInt 0000 = F069 SndRegs equ $F069 | -> SndRegs 0000 = F06C NumByt equ $F06C | -> NumByt 0000 = F06F UnAsm equ $F06F | -> UnAsm 0000 = F072 DisAsm equ $F072 | -> DisAsm 0000 = F075 Tmon equ $F075 | -> TMon 0000 = F078 SYS equ $F078 | -> SYS 0000 = F07B SysIrq equ $F07B | -> SysIrq 0000 | 0000 |--------------------- 0000 | System calls function numbers 0000 |--------------------- 0000 | 0000 = 0000 sysSusp equ $00 | suspend task 0000 = 0001 sysSleep equ $01 | sleep for B clock ticks 0000 = 0002 sysPer equ $02 | periodic schedule 0000 = 0003 sysSched equ $03 | schedule a task 0000 = 0004 sysPar equ $04 | get scheduling par 0000 = 0005 sysSusSig equ $05 | suspend for signal 0000 = 0006 sysSndSig equ $06 | send a signal 0000 = 0007 sysGetRes equ $07 | get/suspend on resources 0000 = 0008 sysGivRes equ $08 | release resources 0000 = 0009 sysSioSnd equ $09 | send data to sio 0000 = 000A sysSioRec equ $0A | receive/wait for sio byte 0000 = 000B sysIntWait equ $0B | wait for an interrupt 0000 = 000C sysIntArm equ $0C | clear interrupt status 0000 ** END INCLUDE ** end 0000 0000 |Defs----------------------------------------------------------- 0000 | 0000 | The I/O ports of the IDE controller 0000 | 0000 = 0500 IoBase equ $0500 | I/O base address for the disk 0000 = 0500 IoCtl equ $0500 | Control byte for IDE 0000 = 0501 IoDatL equ $0501 | Low byte data IDE 0000 = 0502 IoDatH equ $0502 | High byte data IDE 0000 = 0503 IoMod equ $0503 | I/O modus IDE 0000 | 0000 | The I/O modi I use 0000 | 0000 = 0080 DMout equ $80 | all output 0000 = 008B DMin equ $8B | ctl = output, data input 0000 | 0000 | The bits of the control byte 0000 | 0000 = 0000 DCNOP equ %00000000 | Nothing on IDE ctl bus 0000 = 0080 DCRes equ %10000000 | /reset bit 0000 = 0040 DCIor equ %01000000 | /IORD bit 0000 = 0020 DCIow equ %00100000 | /IOWR bit 0000 = 0010 DCCs1 equ %00010000 | /CS1 bit 0000 = 0008 DCCs0 equ %00001000 | /CS0 bit 0000 = 0007 DCADR equ %00000111 | ADR mask bits 0000 | 0000 | IDE adresses 0000 | 0000 = 0007 IDECmd equ $07 | addres for command 0000 = 0007 IDESts equ $07 | addres status register 0000 = 0006 IDEHd equ $06 | addres head number 0000 = 0005 IDECylH equ $05 | addres cylinder number high 0000 = 0004 IDECylL equ $04 | addres cylinder number low 0000 = 0003 IDEsec equ $03 | addres sector number 0000 = 0002 IDEnum equ $02 | addres number of sectors 0000 = 0000 IDEData equ $00 | addres for data bus 0000 = 000E IDERIRQ equ $0E | addres Reset/IRQ register 0000 = 0001 IDEErr equ $01 | addres Error register 0000 | 0000 | The head number (0..F) also has the mask for master/slave 0000 | I fix this at Master, I do not think I will use two drives 0000 | on my IDE interface. 0000 | 0000 = 000F IDEHdA equ %00001111 | head number and mask 0000 = 00A0 IDEHdO equ %10100000 | head number or mask 0000 | 0000 | The Reset/IRQ register has two interesting bits 0000 | 0000 = 0100 IDESRes equ $00000100 | Soft Reset bit 0000 = 0010 IDENIRQ equ $00000010 | 0 = IRQ active 0000 | 0000 | The bits from IDESts 0000 | 0000 = 0080 StsBsy equ %10000000 | busy flag 0000 = 0040 StsRdy equ %01000000 | ready flag 0000 = 0020 StsWft equ %00100000 | Write error 0000 = 0010 StsSKC equ %00010000 | seek complete 0000 = 0008 StsDRQ equ %00001000 | Data Request 0000 = 0004 StsCorr equ %00000100 | ECC executed 0000 = 0002 StsIdx equ %00000010 | Index found 0000 = 0001 StsErr equ %00000001 | error flag 0000 | 0000 | Command opcodes 0000 | 0000 = 0010 CmdRecal equ $10 | recalibrate disk 0000 = 0020 CmdRead equ $20 | write a block 0000 = 0030 CmdWrite equ $30 | read block 0000 = 00E0 CmdStop equ $E0 | Stop disk 0000 = 00E1 CmdStrt equ $E1 | Start disk 0000 = 00EC CmdIdent equ $EC | Identify disk 0000 | 0000 | The default state (I will always leave it in this state) is: 0000 | IDE bus on input, control word == IDENOP ($FF) 0000 | 0000 | I use a memory command packet to tell the disk what to do 0000 | This packet has the following makeup: 0000 | 0000 = 0000 SDA equ 0 | offset source/destination 0000 | address in memory for the 0000 | operation 0000 = 0002 LBA3 equ 2 | offset LBA 0000 = 0003 LBA2 equ 3 | 32-bits number for a disk 0000 = 0004 LBA1 equ 4 | of max 2.1E12 bytes... 0000 = 0005 LBA0 equ 5 | should be enough! 0000 | 0000 | I use Lineair Block Access (LBA) ALL THE TIME. For this disk 0000 | (that does not support it by itself) I have a routine called 0000 | SetLBA to convert the LBA to a CHS configuration. 0000 | 0000 | I use two parameters to decribe the disk geometry: 0000 | 0000 | - The number of blocks per cylinder: 0000 | in CHS terms this is HxS 0000 | 0000 | - The number of blocks per track 0000 | in CHS terms this is S 0000 | 0000 | From these two I can convert LBA to CHS completely. They are 0000 | stored in the following two words: 0000 | 0000 | 42 MB disk: 0000 = 0055 SPC equ 85 | Sectors per Cylinder 0000 = 0011 SPT equ 17 | Sectors per track 0000 | 0000 | 127 MB disk: 0000 |SPC equ 272 | Sectors per Cylinder 0000 |SPT equ 17 | Sectors per track 0000 | 0000 | 212 MB disk: 0000 |SPC equ 420 | Sectors per Cylinder 0000 |SPT equ 35 | Sectors per track 0000 | 0000 | I now use the CPU's /IRQ input to handle the disk's IRQ 0000 | signals. The below parameters are for handling these IRQ-s 0000 | 0000 = 0001 irqdisk equ %00000001 | IRQ bit 0 used for the disk 0000 | 0000 |End------------------------------------------------------------ 0000 0000 |Debug---------------------------------------------------------- 0000 | 0000 | debug defines for this code 0000 | 0000 |End------------------------------------------------------------ 0000 0000 | make the thing as a task 0000 org $4000 | some address 4000 54534B0E db "TSK",$0E | low prio task, a disk is SLOOOW 4004 4040 dw DiskTask | code address 4006 4FFF dw DiskStk | stack 4008 4469736B5461 db "DiskTask" | module name 4010 4010 = 4FFF DiskStk equ $4FFF | leave some room (a LOT, in 4010 | fact) 4010 4010 | command block 0 4010 4800 CMDBLK0:dw $4800 | SDA = $4800 4012 0000 dw $0000 | LBA = $00000000 4014 0000 dw $0000 | 4016 4016 | command block 1 4016 4A00 CMDBLK1:dw $4A00 | SDA = $4A00 4018 0000 dw $0000 | LBA = $00000000 401A 0000 dw $0000 | 401C 401C org $4040 4040 | start of the real code 4040 DiskTask: 4040 868B ldaa #DMin | control bits output, the rest 4042 B70503 staa IoMod | input 4045 4045 | preset control word 4045 8600 ldaa #DCNOP | control word on not active 4047 B70500 staa IoCtl | 404A 404A | make reset pulse on IDE bus 404A 8680 ldaa #DCRes | make a Reset control word 404C B70500 staa IoCtl | set on output 404F 404F C601 ldab #1 | spec says 25 us minimum 4051 8601 ldaa #sysSleep | suspend for 10 ms 4053 BDF078 jsr Sys | 4056 4056 | set control word to not active again 4056 8600 ldaa #DCNOP | 4058 B70500 staa IoCtl | 405B 405B BDF00C diskl: jsr Prompt | give prompt 405E BDF006 diskt1: jsr RecData | 4061 8120 cmpa #' ' | skip spaces 4063 27F9 beq diskt1 | 4065 810D cmpa #CR | 4067 27D7 beq disktask | 4069 4069 | let CI do the real work again 4069 CE4072 ldx #diskttab | 406C BDF02D jsr CI | 406F 7E405B jmp diskl | 4072 4072 diskttab: 4072 3F db '?' | help 4073 408A dw DHelp | 4075 49 db 'I' | identify 4076 4126 dw DIdent | 4078 52 db 'R' | Read sector 4079 4130 dw DRead | 407B 57 db 'W' | Write sector 407C 4137 dw DWrite | 407E 53 db 'S' | Stop disk 407F 413E dw DStop | 4081 57 db 'W' | Start disk 4082 4142 dw DStart | 4084 4E db 'N' | Reset disk 4085 4146 dw DReset | 4087 00 db $00 | what remains 4088 F04B dw NoCmd | 408A 408A CE4091 DHelp: ldx #DHelpTxt | 408D BDF009 jsr SndStr | 4090 39 rts | 4091 4091 DHelpTxt: 4091 0D0A4469736B db cr,lf,"Disk task commands:" 40A6 0D0A db cr,lf 40A8 0D0A49203D20 db cr,lf,"I = Identify disk" 40BB 0D0A52203D20 db cr,lf,"R = Read disk sector" 40D1 0D0A57203D20 db cr,lf,"W = Write disk sector" 40E8 0D0A53203D20 db cr,lf,"S = Stop the disk" 40FB 0D0A55203D20 db cr,lf,"U = Wake up the disk" 4111 0D0A4E203D20 db cr,lf,"N = Reset the disk" 4125 00 db eom 4126 4126 CE4010 DIdent: ldx #CMDBLK0 | 4129 BD43A1 jsr IdentDisk | 412C BD43C5 jsr IdentReport | 412F 39 rts | 4130 4130 CE4010 DRead: ldx #CMDBLK0 | 4133 BD432C jsr ReadSec | 4136 39 rts | 4137 4137 CE4010 DWrite: ldx #CMDBLK0 | 413A BD4361 jsr WriteSec | 413D 39 rts | 413E 413E BD4193 DStop: jsr StopDisk | 4141 39 rts | 4142 4142 BD419C DStart: jsr StartDisk | 4145 39 rts | 4146 4146 BD414A DReset: jsr InitIDE | 4149 39 rts | 414A 414A |--------------------------------------------------------------- 414A | Routine InitIDE 414A | purp: Init the IDE bus 414A | in : nothing 414A | out : nothing 414A | uses: nothing 414A 414A | set I/O port modus to activate the control signals 414A 868B InitIDE:ldaa #DMin | control bits output, the rest 414C B70503 staa IoMod | input 414F 414F | preset control word 414F 8600 ldaa #DCNOP | control word on not active 4151 B70500 staa IoCtl | 4154 4154 | make reset pulse on IDE bus 4154 8680 ldaa #DCRes | make a Reset control word 4156 B70500 staa IoCtl | set on output 4159 4159 C601 ldab #1 | spec says 25 us minimum 415B 8601 ldaa #sysSleep | suspend for 10 ms 415D BDF078 jsr Sys | 4160 4160 | set control word to not active again 4160 8600 ldaa #DCNOP | 4162 B70500 staa IoCtl | 4165 4165 | select the master device, I use a set head number for 4165 | that, The head byte also holds the master/slave select 4165 BD418B jsr SetOut | bus on output 4168 8606 ldaa #IDEHd | set address 416A BD41DA jsr SetAdr | 416D 8600 ldaa #$00 | select head no 0 416F 8AA0 oraa #IDEHdO | or byte 4171 BD41C4 jsr WriteByte | write to the bus 4174 BD4183 jsr SetIn | 4177 4177 | wait till reset executed 4177 BD4212 jsr WaitNBSY | wait till disk is ready.. 417A | THEN start giving orders. 417A 417A | give the disk a recalibrate command 417A 8610 ldaa #CMDRecal | 417C BD41F1 jsr WriteCmd | 417F 417F | wait till command executed 417F BD4212 jsr WaitNBSY | 4182 4182 | done 4182 39 rts | 4183 4183 |--------------------------------------------------------------- 4183 | Routine SetIn 4183 | purp: set all ports of the 8255 for input from the IDE bus 4183 | in : nothing 4183 | out : nothing 4183 | uses: nothing 4183 | NB : This also resets ALL control lines and adr selection 4183 4183 36 SetIn: psha | save accu 4184 868B ldaa #DMin | get control word 4186 B70503 staa IoMod | 4189 32 pula | 418A 39 rts | 418B 418B |--------------------------------------------------------------- 418B | Routine SetOut 418B | purp: set all ports of the 8255 for output to the IDE bus 418B | in : nothing 418B | out : nothing 418B | uses: nothing 418B | NB : This also resets ALL control lines and adr selection 418B 418B 36 SetOut: psha | save accu 418C 8680 ldaa #DMout | get control word 418E B70503 staa IoMod | 4191 32 pula | 4192 39 rts | 4193 4193 |--------------------------------------------------------------- 4193 | Routine StopDisk 4193 | purp: spin down the disk 4193 | in : nothing 4193 | out : nothing 4193 | uses: nothing 4193 4193 StopDisk: 4193 BD4212 jsr WaitNBSY | wait till disk is ready 4196 86E0 ldaa #CMDStop | give the command 4198 BD41F1 jsr WriteCMD | 419B 39 rts | 419C 419C |--------------------------------------------------------------- 419C | Routine StartDisk 419C | purp: spin up the disk 419C | in : nothing 419C | out : nothing 419C | uses: nothing 419C 419C StartDisk: 419C BD4212 jsr WaitNBSY | wait till disk is ready 419F 86E1 ldaa #CMDStrt | give the command 41A1 BD41F1 jsr WriteCMD | 41A4 39 rts | 41A5 41A5 |--------------------------------------------------------------- 41A5 | Routine RecalDisk 41A5 | purp: ReCalibrate the disk 41A5 | in : nothing 41A5 | out : nothing 41A5 | uses: nothing 41A5 41A5 RecalDisk: 41A5 BD4212 jsr WaitNBSY | wait till disk is ready 41A8 8610 ldaa #CMDRecal | give the command 41AA BD41F1 jsr WriteCMD | 41AD 39 rts | 41AE 41AE |--------------------------------------------------------------- 41AE | Routine ReadByte 41AE | purp: Read one byte from the IDE bus 41AE | in : nothing 41AE | out : byte in A 41AE | uses: nothing 41AE | nb : assumes address and bus have been set 41AE 41AE ReadByte: 41AE 37 pshb | save b 41AF F60500 ldab IoCtl | get current 41B2 CA40 orab #DCIor | set Io read 41B4 F70500 stab IoCtl | set 41B7 B60501 ldaa IoDatL | get data 41BA F60500 ldab IoCtl | 41BD C4BF andb #low(not DCIor) | reset IoRead again 41BF F70500 stab IoCtl | 41C2 33 pulb | 41C3 39 rts | 41C4 41C4 |--------------------------------------------------------------- 41C4 | Routine WriteByte 41C4 | purp: Read one byte from the IDE bus 41C4 | in : byte in A 41C4 | out : nothing 41C4 | uses: nothing 41C4 41C4 WriteByte: 41C4 37 pshb | save b 41C5 F60500 ldab IoCtl | get current 41C8 CA20 orab #DCIow | assert Io Write 41CA F70500 stab IoCtl | 41CD B70501 staa IoDatL | get data 41D0 F60500 ldab IoCtl | negate Io Write 41D3 C4DF andb #low(not DCIow) | 41D5 F70500 stab IoCtl | 41D8 33 pulb | 41D9 39 rts | 41DA 41DA |--------------------------------------------------------------- 41DA | Routine SetAdr 41DA | purp: Set an address on the IDE bus 41DA | in : address in A [0 .. F] 41DA | out : nothing 41DA | uses: nothing 41DA 41DA 37 SetAdr: pshb | save B 41DB 36 psha | A too for the moment 41DC 41DC | set which CS to assert 41DC 8408 anda #%00001000 | see if adres > 8 41DE 2704 beq wrad1 | 41E0 8610 ldaa #DCCs1 | high address 41E2 2002 bra wrad2 | 41E4 8608 wrad1: ldaa #DCCs0 | low address 41E6 wrad2: 41E6 | put low bits in place 41E6 33 pulb | addres -> B 41E7 37 pshb | back on stack 41E8 C407 andb #DCAdr | low addres in B 41EA 1B aba | get low addres in A 41EB B70500 staa IoCtl | set on control output 41EE 41EE | get registers back 41EE 32 pula | 41EF 33 pulb | 41F0 39 rts | 41F1 41F1 |--------------------------------------------------------------- 41F1 | Routine WriteCmd 41F1 | purp: Write one command to the IDE device 41F1 | in : command in A 41F1 | out : nothing 41F1 | uses: nothing 41F1 41F1 WriteCmd: 41F1 36 psha | save a 41F2 BD418B jsr SetOut | set bus to output 41F5 8607 ldaa #IDECmd | set address 41F7 BD41DA jsr SetAdr | 41FA 32 pula | get command byte back 41FB BD41C4 jsr WriteByte | write the byte 41FE 39 rts | done 41FF 41FF |--------------------------------------------------------------- 41FF | Routine ReadSts 41FF | purp: get status if the IDE device 41FF | in : nothing 41FF | out : status byte in A 41FF | uses: nothing 41FF 41FF ReadSts: 41FF BD4183 jsr SetIn | set bus to input 4202 8607 ldaa #IDESts | set address 4204 BD41DA jsr SetAdr | 4207 BD41AE jsr ReadByte | read the byte 420A 39 rts | done 420B 420B |--------------------------------------------------------------- 420B | Routine ReadReg 420B | purp: get byte from the IDE device 420B | in : address in A 420B | out : data byte in A 420B | uses: nothing 420B 420B ReadReg: 420B BD41DA jsr SetAdr | 420E BD41AE jsr ReadByte | 4211 39 rts | 4212 4212 |--------------------------------------------------------------- 4212 | Routine WaitNBSY 4212 | purp: wait till the drive indicates ready status 4212 | in : nothing 4212 | out : nothing 4212 | uses: nothing 4212 4212 36 WaitNBSY:psha | save registers 4213 37 pshb | 4214 4214 | test if device ready 4214 BD41FF wtrdy1: jsr ReadSts | get status byte 4217 8480 anda #StsBsy | get status bits 4219 2709 beq wtrdy2 | 421B 421B | not ready, wait 10 ms 421B 8601 ldaa #sysSleep | sleep 421D C601 ldab #1 | one clock cycle 421F BDF078 jsr Sys | 4222 4222 | try again 4222 20F0 bra wtrdy1 | 4224 4224 | device is ready 4224 33 wtrdy2: pulb | 4225 32 pula | 4226 39 rts | done 4227 4227 |--------------------------------------------------------------- 4227 | Routine WaitDRDY 4227 | purp: wait till the drive indicates ready status 4227 | in : nothing 4227 | out : nothing 4227 | uses: nothing 4227 4227 WaitDRDY: 4227 36 psha | save registers 4228 37 pshb | 4229 4229 | test if device ready 4229 BD41FF wtdrdy1:jsr ReadSts | get status byte 422C 8440 anda #StsRdy | get status bits 422E 2609 bne wtdrdy2 | 4230 4230 | not ready, wait 10 ms 4230 8601 ldaa #sysSleep | sleep 4232 C601 ldab #1 | one clock cycle 4234 BDF078 jsr Sys | 4237 4237 | try again 4237 20F0 bra wtdrdy1 | 4239 4239 | device is ready 4239 33 wtdrdy2:pulb | 423A 32 pula | 423B 39 rts | done 423C 423C |--------------------------------------------------------------- 423C | Routine WaitDrq 423C | purp: wait till the drive indicates ready for data status 423C | in : nothing 423C | out : nothing 423C | uses: nothing 423C 423C 36 WaitDrq:psha | save registers 423D 37 pshb | 423E 423E | test if device ready for data 423E BD41FF wtdrq1: jsr ReadSts | get status byte 4241 8408 anda #StsDrq | get status bits 4243 2609 bne wtdrq2 | 4245 4245 | not ready, wait 10 ms 4245 8601 ldaa #sysSleep | sleep 4247 C601 ldab #1 | one clock cycle 4249 BDF078 jsr Sys | 424C 424C | try again 424C 20F0 bra wtdrq1 | 424E 424E | device is ready for data 424E 33 wtdrq2: pulb | 424F 32 pula | 4250 39 rts | done 4251 4251 |--------------------------------------------------------------- 4251 | Routine ReadBlock 4251 | purp: read one block from the IDE device 4251 | in : X -> result address (512 bytes) 4251 | out : nothing 4251 | uses: nothing 4251 4251 ReadBlock: 4251 | save registers 4251 36 psha | 4252 37 pshb | 4253 3C pshx | 4254 4254 | setup for data read 4254 BD4183 jsr SetIn | set to input 4257 8600 ldaa #IDEData | set address 4259 BD41DA jsr SetAdr | 425C 425C | init loop counter 425C 8600 ldaa #$00 | 256 word reads 425E 425E F60500 rdblk1: ldab IoCtl | get current 4261 CA40 orab #DCIor | assert Io Read 4263 F70500 stab IoCtl | set 4266 4266 F60501 ldab IoDatL | get low byte 4269 E700 stab 0,X | store 426B 08 inx | 426C 426C F60502 ldab IoDatH | get high data 426F E700 stab 0,X | store 4271 08 inx | 4272 4272 F60500 ldab IoCtl | 4275 C4BF andb #low(not DCIor) | negate Io Read 4277 F70500 stab IoCtl | 427A 427A 4A deca | 427B 26E1 bne rdblk1 | loop 427D 427D | done, get things back 427D 38 pulx | 427E 33 pulb | 427F 32 pula | 4280 39 rts | 4281 4281 |--------------------------------------------------------------- 4281 | Routine WriteBlock 4281 | purp: write one block of data to the IDE device 4281 | in : X -> data address (512 bytes) 4281 | out : nothing 4281 | uses: nothing 4281 4281 WriteBlock: 4281 | save registers 4281 36 psha | 4282 37 pshb | 4283 3C pshx | 4284 4284 | setup for data write 4284 BD418B jsr SetOut | bus to output 4287 8600 ldaa #IDEData | set address 4289 BD41DA jsr SetAdr | 428C 428C | init loop counter 428C 8600 ldaa #$00 | 256 word write 428E 428E E600 wrblk1: ldab 0,X | write data byte 4290 F70501 stab IoDatL | to I/O ports 4293 08 inx | 4294 E600 ldab 0,X | 4296 F70502 stab IoDatH | 4299 08 inx | 429A 429A F60500 ldab IoCtl | strobe write 429D CA20 orab #DCIoW | assert Io Write 429F F70500 stab IoCtl | 42A2 C4DF andb #low(not DCIoW) | negate Io Write 42A4 F70500 stab IoCtl | 42A7 42A7 4A deca | loop 42A8 26E4 bne wrblk1 | 42AA 42AA | done, get things back 42AA 38 pulx | 42AB 33 pulb | 42AC 32 pula | 42AD 39 rts | 42AE 42AE |--------------------------------------------------------------- 42AE | Routine SetLBA 42AE | purp: sets the LBA for the next transfer 42AE | in : X -> command packet 42AE | X+0 = ..\ not used or changed here 42AE | X+1 = ../ 42AE | X+2 = LBA3 (high) 42AE | X+2 = LBA2 42AE | X+3 = LBA1 42AE | X+4 = LBA0 (low) 42AE | out : registers of the IDE controller loaded 42AE | uses: nothing 42AE | 42AE | NB: I select ONE sector to be processed 42AE | 42AE | I make a stack frame to convert, these are the offsets in 42AE | the stack frame (after tsx, relative to X) 42AE = 0000 LBS3 equ 0 | stack frame LBAS 42AE = 0001 LBS2 equ 1 | 42AE = 0002 LBS1 equ 2 | 42AE = 0003 LBS0 equ 3 | cylinder high 42AE 42AE SetLBA: 42AE | prepare for disk output 42AE BD418B jsr SetOut | 42B1 42B1 | load input data to stack 42B1 3C pshx | save X 42B2 A605 ldaa LBA0,X | 42B4 36 psha | 3 42B5 A604 ldaa LBA1,X | 42B7 36 psha | 2 42B8 A603 ldaa LBA2,X | 42BA 36 psha | 1 42BB A602 ldaa LBA3,X | 42BD 36 psha | 0 42BE 30 tsx | make X stack frame pointer 42BF 42BF | init for divide by SPC (=sectors/cylinder) 42BF | to get the cylinder number. I know the result 42BF | will fit in 16 bits, so 16 bits result is enough. 42BF C610 ldab #16 | 16 divide loops 42C1 42C1 37 lbac1: pshb | save counter on stack 42C2 42C2 |shift 1 place to left, fill with 0 bit 42C2 6803 asl LBS0,X | shift divident, 42C4 6902 rol LBS1,X | fill up with 0 42C6 6901 rol LBS2,X | 42C8 6900 rol LBS3,X | 42CA 42CA | test if substract fits 42CA EC00 ldd LBS3,X | get high word 42CC 830055 subd #SPC | 42CF 2504 bcs lbac2 | does not fit, next loop again 42D1 42D1 | fits, set lower cylinder bit, store result 42D1 ED00 std LBS3,X | 42D3 6C03 inc LBS0,X | 42D5 42D5 | handle loop things 42D5 33 lbac2: pulb | 42D6 5A decb | 42D7 26E8 bne lbac1 | 42D9 42D9 | write result to disk registers 42D9 8604 ldaa #IDECylL | 42DB BD41DA jsr SetAdr | 42DE A603 ldaa LBS0,X | 42E0 BD41C4 jsr WriteByte | 42E3 8605 ldaa #IDECylH | 42E5 BD41DA jsr SetAdr | 42E8 A602 ldaa LBS1,X | 42EA BD41C4 jsr WriteByte | 42ED 42ED | see about head number 42ED 8600 ldaa #0 | simple substract will do the 42EF A703 staa LBS0,X | work, max H times... 42F1 42F1 | get remaining blocks count 42F1 EC00 ldd LBS3,X | 42F3 42F3 | test if one head more 42F3 830011 lbac3: subd #SPT | minus one track's sectors 42F6 2504 bcs lbac4 | see if reult is minus 42F8 6C03 inc LBS0,X | no, one more head 42FA 20F7 bra lbac3 | 42FC 42FC | gone one too far already 42FC C30011 lbac4: addd #SPT | and sector count 42FF C30001 addd #$0001 | sector count starts at 1 !! 4302 ED00 std LBS3,X | save for a moment 4304 4304 | write to disk registers 4304 8606 ldaa #IDEHd | Head is special 4306 BD41DA jsr SetAdr | 4309 A603 ldaa LBS0,X | 430B 840F anda #IDEHdA | have to set some bits 430D 8AA0 oraa #IDEHdO | to get it working good 430F BD41C4 jsr WriteByte | 4312 4312 8603 ldaa #IDESec | sectors is easy again 4314 BD41DA jsr SetAdr | 4317 A601 ldaa LBS2,X | low byte only as sector # 4319 BD41C4 jsr WriteByte | 431C 431C | set up for ONE sector transfer 431C 8602 ldaa #IDEnum | 431E BD41DA jsr SetAdr | 4321 8601 ldaa #1 | 4323 BD41C4 jsr WriteByte | 4326 4326 | clean up the stack 4326 31 ins | four bytes LBA 4327 31 ins | 4328 31 ins | 4329 31 ins | 432A 432A | get X back too 432A 38 pulx | 432B 432B | done 432B 39 rts | 432C 432C |--------------------------------------------------------------- 432C | Routine ReadSec 432C | purp: reads one sector from the disk 432C | in : X -> command packet 432C | X+0 = dest addres high 432C | X+1 = dest addres low 432C | X+2 = LBA3 432C | X+3 = LBA2 432C | X+4 = LBA1 432C | X+5 = LBA0 432C | out : data read into the destination address 432C | uses: nothing 432C 432C | wait for bsy bit cleared 432C BD4212 ReadSec:jsr WaitNBSY | wait till disk is ready 432F 432F | select the device 0 432F 8606 ldaa #IDEHd | set address 4331 BD41DA jsr SetAdr | 4334 8600 ldaa #$00 | set head no = 0 4336 840F anda #IDEHdA | 4338 8AA0 oraa #IDEHdO | 433A BD41C4 jsr WriteByte | 433D 433D | load parameters 433D BD42AE rdsec0: jsr SetLBA | set address 4340 4340 8620 ldaa #CmdRead | give read command 4342 BD41F1 jsr WriteCmd | 4345 4345 | wait for busy gone 4345 BD4212 jsr WaitNBSY | 4348 4348 | test on errors 4348 BD41FF jsr ReadSts | get status byte 434B 16 tab | 434C 8401 anda #StsErr | check error bit 434E 2703 beq rdsec1 | no error -> cont 4350 4350 | error, notify 4350 BD44D6 jsr DiskErr | report the error 4353 17 rdsec1: tba | test if DRQ 4354 8408 anda #StsDRQ | 4356 2601 bne rdsec2 | 4358 4358 | no data requested, quit 4358 39 rts | 4359 4359 | transport the data block to destination 4359 3C rdsec2: pshx | 435A EE00 ldx SDA,X | get dest address 435C BD4251 jsr ReadBlock | get the data 435F 38 pulx | 4360 4360 39 rts | done 4361 4361 |--------------------------------------------------------------- 4361 | Routine WriteSec 4361 | purp: Write one sector to the disk 4361 | in : X -> command packet 4361 | X+0 = source addres high 4361 | X+1 = source addres low 4361 | X+2 = LBA High 4361 | X+3 = LBA Middle 4361 | X+4 = LBA low 4361 | out : data written to the disk 4361 | uses: nothing 4361 4361 WriteSec: 4361 BD4212 jsr WaitNBSY | wait till disk is ready 4364 4364 | select the device 0 4364 8606 ldaa #IDEHd | set address 4366 BD41DA jsr SetAdr | 4369 8600 ldaa #$00 | set head no = 0 436B 840F anda #IDEHdA | 436D 8AA0 oraa #IDEHdO | 436F BD41C4 jsr WriteByte | 4372 4372 BD42AE jsr SetLBA | set address 4375 4375 8630 ldaa #CmdWrite | give write command 4377 BD41F1 jsr WriteCmd | 437A 437A | wait till command ready 437A BD4212 jsr WaitNBSY | 437D 437D | test on errors 437D BD41FF jsr ReadSts | get status byte 4380 16 tab | 4381 8401 anda #StsErr | check error bit 4383 2703 beq wrsec1 | no error -> cont 4385 4385 | error, notify 4385 BD44D6 jsr DiskErr | report the error 4388 17 wrsec1: tba | test if DRQ 4389 8408 anda #StsDRQ | 438B 2601 bne wrsec2 | 438D 438D | no data requested, quit 438D 39 rts | 438E 438E | transport the data block to destination 438E 3C wrsec2: pshx | 438F EE00 ldx SDA,X | get dest address 4391 BD4281 jsr WriteBlock | get the data 4394 38 pulx | 4395 4395 39 rts | done 4396 4396 BD423C jsr WaitDRQ | wait for data 4399 3C pshx | 439A EE00 ldx SDA,X | get dest address 439C BD4281 jsr WriteBlock | get data 439F 38 pulx | 43A0 39 rts | 43A1 43A1 |--------------------------------------------------------------- 43A1 | Routine IdentDisk 43A1 | purp: Get the disk's parameters from the disk itself 43A1 | in : X -> command packet 43A1 | X+0 = dest addres high 43A1 | X+1 = dest addres low 43A1 | out : ident packet from the disk in memory 43A1 | uses: nothing 43A1 43A1 IdentDisk: 43A1 BD4212 jsr WaitNBSY | wait till disk ready 43A4 43A4 | give command 43A4 86EC ldaa #CmdIdent | send Ident command 43A6 BD41F1 jsr WriteCmd | 43A9 43A9 | wait for busy gone 43A9 BD4212 jsr WaitNBSY | 43AC 43AC | test on errors 43AC BD41FF jsr ReadSts | get status byte 43AF 16 tab | 43B0 8401 anda #StsErr | check error bit 43B2 2703 beq idget1 | no error -> cont 43B4 43B4 | error, notify 43B4 BD44D6 jsr DiskErr | report the error 43B7 17 idget1: tba | test if DRQ 43B8 8408 anda #StsDRQ | 43BA 2601 bne idget2 | 43BC 43BC | no data requested, quit 43BC 39 rts | 43BD 43BD | transport the data block to destination 43BD 3C idget2: pshx | 43BE EE00 ldx SDA,X | get dest address 43C0 BD4251 jsr ReadBlock | get the data 43C3 38 pulx | 43C4 43C4 39 rts | done 43C5 43C5 |--------------------------------------------------------------- 43C5 | Routine IdentReport 43C5 | purp: give extensive disk identification report 43C5 | in : X -> disk command packet 43C5 | out : disk ident info via the sio 43C5 | uses: registers 43C5 43C5 IdentReport: 43C5 | data packet pointed to by the disk command packet 43C5 36 psha | save registers 43C6 37 pshb | 43C7 3C pshx | save x too 43C8 43C8 | make X -> ident info NB: this is in LOW-HIGH (Intel) 43C8 | word format. I want to be SOMEWHAT compatible with 43C8 | a PC. Perhaps I can someday read the file-system I make 43C8 | with a PC too... 43C8 EE00 ldx SDA,X | x -> ident data 43CA 3C pshx | 43CB 43CB | go dump info 43CB CE445D ldx #IDModel | model name 43CE BDF009 jsr SndStr | 43D1 38 pulx | 43D2 3C pshx | 43D3 C636 ldab #54 | start in SDA block 43D5 3A abx | 43D6 C614 ldab #20 | 20 words 43D8 43D8 | see if any name there 43D8 6D01 tst 1,X | 43DA 2711 beq idnm | zero byte -> no model there 43DC 43DC | go print the model name 43DC A601 idml: ldaa 1,X | first byte (LOW-HIGH) 43DE BDF000 jsr SndData | 43E1 A600 ldaa 0,X | 43E3 BDF000 jsr SndData | 43E6 08 inx | 43E7 08 inx | 43E8 5A decb | 43E9 26F1 bne idml | 43EB 2006 bra idme | 43ED 43ED | no name given 43ED CE446D idnm: ldx #IDNoMod | 43F0 BDF009 jsr SndStr | 43F3 43F3 | name done 43F3 01 idme: nop | 43F4 43F4 | see about ATA/ATAPI modus 43F4 38 pulx | 43F5 3C pshx | 43F6 CE447B ldx #IdAta | 43F9 BDF009 jsr SndStr | 43FC 38 pulx | 43FD 3C pshx | 43FE A601 ldaa 1,X | get ATA/ATAPI status 4400 8480 anda #$80 | highest bit 4402 2705 beq riata | 4404 4404 | is an ATAPI device 4404 CE4491 ldx #IdMAtapi | 4407 2003 bra israta | 4409 4409 | is an ATA device 4409 CE448B riata: ldx #IdMAta | 440C 440C | print device type 440C BDF009 israta: jsr SndStr | 440F 440F | see about removable/fixed 440F 38 pulx | 4410 3C pshx | 4411 A600 ldaa 0,X | 4413 8440 anda #$40 | seems to be bit 6 4415 2705 beq rirem | 4417 4417 | is a fixed disk 4417 CE4499 ldx #IDFix | 441A 2003 bra rifrm | 441C 441C | is a removable disk 441C CE449F rirem: ldx #IDRem | 441F BDF009 rifrm: jsr SndStr | 4422 4422 | get number of cylinders 4422 CE44A9 ldx #IDCyl | 4425 BDF009 jsr SndStr | 4428 38 pulx | 4429 3C pshx | 442A A603 ldaa 3,X | 442C BDF01E jsr SndHex | 442F A602 ldaa 2,X | 4431 BDF021 jsr SndHex1 | 4434 4434 | get number of heads 4434 CE44B8 ldx #IDHead | 4437 BDF009 jsr SndStr | 443A 38 pulx | 443B 3C pshx | 443C A607 ldaa 7,X | 443E BDF01E jsr SndHex | 4441 A606 ldaa 6,X | 4443 BDF021 jsr SndHex1 | 4446 4446 | get number of sectors 4446 CE44C7 ldx #IDSec | 4449 BDF009 jsr SndStr | 444C 38 pulx | 444D 3C pshx | 444E A60D ldaa 13,X | 4450 BDF01E jsr SndHex | 4453 A60C ldaa 12,X | 4455 BDF021 jsr SndHex1 | 4458 4458 38 pulx | X -> data block 4459 38 pulx | X -> command packet 445A 33 pulb | restore registers 445B 32 pula | 445C 39 rts | done 445D 445D 0D0A44657669 IDModel:db cr,lf,"Device name: ",eom 446D 4E6F74207370 IDNoMod:db "Not specified",eom 447B 447B 0D0A44657669 IDAta: db cr,lf,"Device type: ",eom 448B 4154412C2000 IDMAta: db "ATA, ",eom 4491 41544150492C IDMAtapi:db "ATAPI, ",eom 4499 466978656400 IDFix: db "Fixed",eom 449F 52656D6F7661 IDRem: db "Removable",eom 44A9 44A9 0D0A43796C69 IDCyl: db cr,lf,"Cylinders :",eom 44B8 0D0A48656164 IDHead: db cr,lf,"Heads :",eom 44C7 0D0A53656374 IDSec: db cr,lf,"Sectors :",eom 44D6 44D6 |--------------------------------------------------------------- 44D6 | Routine DiskErr 44D6 | purp: give extensive error reporting for disk errors 44D6 | in : X -> disk command packet 44D6 | out : error messages about what went wrong with a disk access 44D6 | uses: registers 44D6 44D6 36 DiskErr:psha | save registers 44D7 37 pshb | 44D8 3C pshx | save pointer to LBA 44D9 44D9 | general error message 44D9 CE4542 ldx #ErrDsk | 44DC BDF009 jsr SndStr | 44DF 44DF | status 44DF CE4555 ldx #ErrSts | give error string 44E2 BDF009 jsr SndStr | 44E5 8607 ldaa #IDESts | first the IDE Staus register 44E7 BD420B jsr ReadReg | 44EA BDF01E jsr SndHex | 44ED 44ED | the error bits 44ED CE4563 ldx #ErrBit | 44F0 BDF009 jsr SndStr | 44F3 8601 ldaa #IDEErr | 44F5 BD420B jsr ReadReg | 44F8 BDF01E jsr SndHex | 44FB 44FB | LBA here it happened 44FB CE4571 ldx #ErrLBA | 44FE BDF009 jsr SndStr | 4501 38 pulx | 4502 3C pshx | 4503 EC02 ldd LBA3,X | 4505 BDF01E jsr SndHex | 4508 17 tba | 4509 BDF021 jsr SndHex1 | 450C EC04 ldd LBA1,X | 450E BDF021 jsr SndHex1 | 4511 17 tba | 4512 BDF021 jsr SndHex1 | 4515 4515 | the CHS where it happened 4515 CE457F ldx #ErrCHS | 4518 BDF009 jsr SndStr | 451B 8605 ldaa #IDECylH | 451D BD420B jsr ReadReg | 4520 BDF01E jsr SndHex | 4523 8604 ldaa #IDECYLL | 4525 BD420B jsr ReadReg | 4528 BDF021 jsr SndHex1 | 452B 8606 ldaa #IDEHd | 452D BD420B jsr ReadReg | 4530 BDF01E jsr SndHex | 4533 8603 ldaa #IDEsec | 4535 BD420B jsr ReadReg | 4538 BDF01E jsr SndHex | 453B 453B | end with a new line 453B BDF00F jsr NewLine | 453E 453E | get registers back 453E 38 pulx | 453F 33 pulb | 4540 32 pula | 4541 4541 | done 4541 39 rts | 4542 4542 0D0A3E3E2044 ErrDsk: db cr,lf,">> Disk Error <<",eom 4555 0D0A3E3E2053 ErrSts: db cr,lf,">> Status :",eom 4563 0D0A3E3E2045 ErrBit: db cr,lf,">> Error :",eom 4571 0D0A3E3E204C ErrLBA: db cr,lf,">> LBA :",eom 457F 0D0A3E3E2043 ErrCHS: db cr,LF,">> CHS :",eom 458D 458D |---------------------------------------------------- 458D 458D > 0000 end >>>>>>>>>>>>>>>>>>>> End 63B03 assembly listing <<<<<<<<<<<<<<<<<<
file: /Techref/io/ide/8255-ide.txt, 109KB, , updated: 1999/8/6 10:15, local time: 2024/12/2 03:05,
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