A interesting discovery.

[Kevin McGuire]

I made a very interesting discovery today. Actually. I knew such stuff existed but I did not expect to find it near my home town. What makes it more intriguing is that I only paid four U.S. dollars. It was contained in a small cardboard package with a plastic cover holding the contents securely. It came with two, not just one, but two. The size is about 2 inches by 1/4 inch and is called the "Z80A" and part of the Z80 family.

The CPU model is Z80A and runs at 4MHZ. It has only 40 pins. It is also a 8 bit CPU with a 16 bit address bus to allow it support up to 64K of memory (which I also bought - for five dollars.).

And, of course I had no idea exactly what I was buying but for something so cheap and such a small pin count it has to be a attainable goal of getting it work in a few years or less.

References:
http://www.geocities.com/siliconvalley/ ... 0brief.htm

[srg_13]

Check out this site. It has a circuit that you can use to make a Sinclair ZX80. It has a rom image that you can burn onto an eprom, and a full circuit.

I want to try it out, because I think it would be really cool to make a working computer!

-Stephen

[Kevin McGuire]

http://home.micros.users.btopenworld.com/zx80/zx80.html

That is very interesting, and amazing how the keyboard was made. I also noticed he used a board that had no traces and had put soilder on the bottom from pin to wire - interesting.

I myself would like to do the same, but honestly I would be excited just to get a circuit built to upload some code to my EPROM, get the clock circuit and reset circuit in, and find some way to watch it execute the code from the memory.

I want to try it out, because I think it would be really cool to make a working computer!

If you get it working let me know. I would be execited to hear.

I found a Z80 instruction set assembler. I installed it but I have not used it.
http://little-bat.de/prog/