Two questions:
1.A description for Port A states "symmetrical drive". Can someone, in lay terms, explain what that refers to, and how it is used.

2.Is their a way of adding or accessing more data memory. This would be within the context of the SX proto board. The docs state 262x8, I guess to some, salvation would be in order. But since their is a 5 bit addressing scheme, have I answered my own question.

Thanks
PS please save the sarcasm for someone else.

Hi There;
Symmetrical drive means the transistors in the port can "push" (source current) equally well as they can "pull" (sink current).

As far as data memory is concerned; not directly, but certainly via software, either parallel (uses lots of I/O pins) or serial uses many fewer I/O pins).

Peter, thanks for answering the questions without a brow beating. Could you answer two more?
1.Hi-Z input or output, is this like turbo mode(lol)?

2.TTL and CMOS,  which would be preference.

Thanks.

1. Hi-Z (high impedance) in when the pin is set to an input state; when made an output there is a low-impedance path to Vdd (high) or Vss (low).

2. That depends on where you want the transition to occur.  When timing the discharge of a cap, for example, TTL is preferable as the transition is at 1.4 volts so there is a greater "distance" between 5 (fully charged) and 1.4 (transition to 0).  If the pin was set to CMOS and running at 5 volts, the transition point would be 2.5 volts.  Given the same cap timing routine, the granularity would be greater.

Well no, they are totally different issues.

Turbo refers to the mode the SX is operating in; that is downward compatible with some (1655??) PIC's reduced feature set. Hi-Z refers to an output's being temporarily disconnected so it neither sinks or sources. Inputs are always (relatively) Hi-Z.

TTL/CMOS depends somewat on your application. In the many years I have been programming the SX, I have never yet used TTL. I like the concept of the processor switching at half of Vcc. It allows me to play a lot of analog tricks with the SX.

TURBO Mode ???

When I bought a PC software product many years ago, it came together with a bumper sticker reading "I feel the need for speed" - fortunately not too many German cops understand English :-) .

Using an SX comes close to driving a racing car, so why should you throttle it down?

Therefore, each of your assembly programs (for SXes below 48) should contain those two directives:

DEVICE TURBO
DEVICE OPTIONX to make use of their full power (not necessary for the "larger" 48/52 devices - they are racing cars by default).