Requesting Help with Vintage Comp in Progress

[sbdroni]

Hi, I'm really interested in building a vintage computer similar to the one that's featured at this link: http://kaput.retroarchive.org/

I'm doing this primarily for enjoyment of programming 8-bit music and maybe some ASM. But I was wondering if someone could help me out a bit? I got my hands on an Intel C8080A and a MOS 6581 SID C64 chip to put into my system. What I need to know is what sort of board, cards (display etc), or psu I would need to include.

Thanks in advance!

[Thrashbarg]

Hi,

For a minimal computer you'll want a CPU (of course), some RAM and ROM, and a serial port to communicate to it through a terminal, such as HyperTerminal or Kermit. Anything else (such as the SID) is extra.

A simple computer like this can be built on the one board. You need a *lot* of patience when you wire it up too.

While I think of it, do you just have an 8080 by itself? Because it needs support components, unlike the 8085 and Z80. The 8224 clock generator and 8228/8238 bus driver are the easiest to use if you can find them, because they're intended to be used with the 8080. You can use discrete logic but it's a hassle.

http://kaput.homeunix.org/~thrashbarg/Z80SBC.png is a minimal Z80 computer I designed. Feel free to use it.

Also, I made the computer in question :)

[sbdroni]

Whoaaaaaa no way!!!

I must commend you because you sir, made one hell of an awesome computer!

I have the 8080 by itself, so I'm probably going to need to find those extra support components somewhere (maybe ebay?).

Anyways nice to meet you!! :D

[MikeS]

What's in the EPROM of that Z80 SBC?

m

[MikeS]

A couple of questions re the Z80 SBC schematic:

- What's the source of the EEPROM /CE and the input of the 'LS04 driving the RAM /CE?
- No problem driving the LEDs directly?
- Is the EEPROM code available by any chance?

Thanks,

m

[johnorun]

I have the 8080 by itself, so I'm probably going to need to find those extra support components somewhere (maybe ebay?). :D

For help with the chips above try the forum at this site: www.cpu-world.com
Lots of friendly chip experts that will help you out. :)

[Thrashbarg]

- What's the source of the EEPROM /CE and the input of the 'LS04 driving the RAM /CE?

A15. When it's low the EEPROM is accessed, when it's high the RAM is accessed. I wanted to keep it as simple as possible.

- No problem driving the LEDs directly?

I've never had a problem. It might reduce the life span of the IC a little but this isn't exactly a mission critical system. Again I'm trying to keep it simple.

- Is the EEPROM code available by any chance?

No, I've left that up to the builder.

[MikeS]

- What's the source of the EEPROM /CE and the input of the 'LS04 driving the RAM /CE?

A15. When it's low the EEPROM is accessed, when it's high the RAM is accessed. I wanted to keep it as simple as possible.

---
D'oh! Of course! Thought it referred to the left side, not the right; sorry.

m