Just recently as some of you may know, I was inquiring about using an SX chip versus some standard logic ICs to make a circuit. After some smart talk by forum members it was clear that the SX was the choice (see the thread recently in this forum titled "need help"). I had already been using an Sx48 and the prospective soldering job of the surface mount was a deterrant for me but members suggested a few good sites to bone up on those skills. But then I saw the SX28 (DIP) and decided that would work just as well too, thereby saving a lot of space by shelving my multiple IC counting circuit and reducing the size of my workspace to less than the 48SX protoboard (its too big for my needs).

Here is the problem. I actually havemy new SX28 DIP in a breadboard. I took the SX-Key connector and out of necessity I soldered extensions to the pins  to make it stay in the board. The process went without a problem and I tested each lead after soldering to make sure electrical connection was intact. I think I made all of the appropriate electrical connections to the SX but when I try to connect to it I get a "chip connection failed" error that I can't seem to shake. I don't have a pullup resistor at the master clear and grounded the pin. My five volt supply seems intact and I have pin 27 to OSC1, pin 28 to OSC2, pin 4 to ground and SXkey ground and pin 2 to supply voltage and SX key supply. What could I be doing wrong?

> I don't have a pullup resistor at the master clear and grounded the pin.

err, why?

> What could I be doing wrong?

See above...

If you ground the /MCLR pin then you are hold the device in reset. It cannot be programmed while in reset. You need to have the pull-up resistor to hold /MCLR high so the device will run and you can program it.
Bean.

The on-site literature that came with it said that if it is externally controlled (I guess they mean the SX key right?) not to use the pull up resistor. Do I still use the pull up resistor with the SX-Key?

No, the SX-Key does not connect to MCLR, so you need the 10K pull-up.

BTW: The same is true for the SX48 you've been using already, or any other SX chip. /MCLR is an inverting input, i.e. it does (or holds the chip in) a reset when low.

The 10k pull-up solved that problem. It makes sense to me, just the way it was explained in the datasheet wasn't.

I've got a new problem: it is able to connect to it but it says "Verify failed at oscillator". I don't have an oscillator hooked up; I wanted to generate it for the time being from the SX-key. Is that error message a problem?

Geunther thanks for the recommendation on the LM2574. Its working great!!

BebopALot,
What are you doing when you get the "verify" error?  I pretty sure the verify error only come when you hit the "Verify" button on the "Device" dialog and the code in the chip doesn't match the code in the device dialog buffer.  
If you are using the device dialog, my recommendation is to just stay away from it completely.  Pretty much everything you need to do can and should be done from the main IDE toolbar buttons and menu selections.  If you want to program the chip, dont use the device dialog but use the main IDE instead.

Yes I have been using the device dialog. I'll try using the IDE and see if that doesn't allow me to go forward. Thanks.