My 2nd Computer 1978-1988
Z80 running at 2mhz

z80-1.jpg (66610 bytes)

z80-2.jpg (39025 bytes)

The gray box is the main controller.  It could take over control of the buss and slow down, or step the CPU.

The Black box is a Heathkit Dual Floppy holder.  I could not get their control card to work in my system, so I designed my own which is the first tall blue card.

The green board is a video card.  The only card I purchase.  I didn't have enough know how to make an analog card.  It used an S100 buss. My buss was wired as I need it.

The board with all the chip is my first 4k of memory. Each chip is 1x1k.  Its the only part I used from my first computer, an Intel 8080, it ran from Jul 1976 - 1978

The first white board is the z80 CPU board. The 3rd was a memory board that was always on.  It was my OS.  Later the I used EPROM.

The card in the cable it a real time clock.  The same chip that was later used in the AT type computers.

The red cable goes to the math processor board.

It had a total of 27k of ram, with 4 2k EPROM.  1k of video memory.

I wrote a word processor, an accounting program, some games, assembler, debugger and dissembler.  And of course the OS.

Later I bought a Commodore 64.  I connect the 2 computer through a parallel port.  I wrote a assembler on the z80 for the 64.  My 64 debugger was the z80.

The computer worked for 10 years then the wire wrap started to fail.  It was a sad day when I turned it off the last time.

Other parts not shown:
1. Speech unit
2. EPROM burner
3. A 8 digit led display (Lower left of second picture)
4. Full keyboard
5. Printer a daisywheel. Which I still have.