I have collection of old materials about computers. Some of them are hard to find on the Internet, so I decided, to publish them here.


PMD 85-1 ROM Disassembly (commented in Czech language)

I don't know how long it took me to copy this disassembly back in 1987, when I borrowed the original printed on endless paper, but I used one and half school A4 exercise book. But it took me several months to convert it to html. So, here is the result: Komentovaný výpis ROM monitoru PMD 85-1

Intel 4040 Reference (architecture, instruction set)

It is not that complicated to find detailed info about Intel 4004, but it is very hard to find anything detailed about Intel 4040, its architecture, registers, instruction set, pins, etc. I've got a copy of Intel MCS-40 User's Manual, so I put something here. Note, that it is still under construction: Intel 4040 CPU. Here are 4040 opcodes.
- For reference here are: 4004 opcodes.

Acorn Electron Hardware

I've got an old and working Acorn Electron. I wrote some programs to discover its hardware details. I discovered, that some of the info about its hardware over the Internet is wrong. So I put my findings here. Note, that it is under construction: Acorn Electron Hardware

6502 CPU

MOS Technology 6502 is known well enough. You can find manuals on every corner. Here it is just for the sake of completness, as it is main CPU of Acorn Electon. I put the info for my own reference too. So, let's start from opcodes. Note, that it is under construction: 6502 opcodes

Intel 8080 CPU (8080A)

Descriptions of this CPU are very common too, but it's here from the same reason as 6502 - it was the CPU of PMD 85, hardware of which I describe here one day. So, opcodes, mnemonics, lenghts, cycles, flags affected are here: 8080 opcodes (16 columns) and 8080 opcodes (8 columns).
- For reference here are Datapoint 2200 opcodes: Datapoint 2200 opcodes
- For reference here are 8008 opcodes: 8008 opcodes
- For reference here are 8085 opcodes with undocumented instructions and flags: 8085 opcodes
- For reference here are Gameboy CPU (LR35902) opcodes: Gameboy opcodes

Intel 8086 CPU

Descriptions of this CPU are very common too, but it's here from the same reason as 6502 - its variant 8088 was the CPU of IBM PC XT, hardware of which I describe here one day. So, opcodes, mnemonics, lenghts, cycles, flags affected are here: 8086 opcodes - note, that MOD/RM byte is there so far.

Intel 8088 CPU

Opcodes, mnemonics, lenghts, cycles, flags affected are here: 8088 opcodes - note, it is not fully ready, should be ready in one month or so.




Some (yet unsorted) info about NMOS could be found here: Basic NMOS gates



Intel 8085 (AMD 9085) internal structure

I have drawn the layers of the AMD 9085 CPU based on photographs published in visual6502 project. As I believe the internal structure of AMD 9085 is the same as Intel 8085, i.e. it is 100% clone.
Here is the picture of the combined AMD 9085 layers I have made.
The content of its instruction decode ROM is here.
The content of its instruction timing ROM is here.
The content of its instruction groups ROM is here.
The content of its register timing ROM is here.
The content of its register control ROM is here.
Points of interest (i.e. registers' coordinations) is here.
Partial schematics of the chip is here.