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I never played around with the 8080 before, and wasn't sure where to start, so I googled some quick resources. Wondering if anyone knows of better resources?
* The original manual - https://altairclone.com/downloads/manuals/8080%20Programmers...
* Wikipedia article - https://en.wikipedia.org/wiki/Intel_8080
* Summary of instructions - http://www.classiccmp.org/dunfield/r/8080.txt
As background, the oral history panel on the 8080 is hard to beat [1]. It was designed by broadly the same team (led by Federico Faggin) that did the first commercial microprocessor, the 4004, and then the Z80, which somewhat overshadowed the 8080 commercially.
[1] https://www.computerhistory.org/collections/catalog/10265812...
There are a few more old manuals here: http://bitsavers.trailing-edge.com/components/intel/MCS80/
The interesting thing about the older documentation is that it seems to be written assuming far less existing knowledge of the reader, which I find makes them much more accessible to beginners.
This is great and a useful addition to the range of online emulators.
I'd really like to see an online simulation of one of the early 8 bit chips (8080, 6502 or Z80) say that sits at a level between gates (visual6502) and simply implementing the machine code instructions - one where it would be possible to follow what is happening at block level on each clock cycle and where you could see data flows within the CPU? Hopefully that would give useful insight into early CPU design.
Does anyone know of such a simulator?
Maybe this?
Z80 Explorer – a Zilog Z80 netlist-level simulator from 6 days ago.
Thank you!
I did see this when it appeared on HN but thought it was effectively a Visual 6502 but for the Z80. Having downloaded and looked in more detail I see that it has a lot more information than I originally thought.
Even better, the accompanying blog posts (eg [1]) give as good a description of the layout of the Z80 and the relationship between the various elements as I have seen anywhere for any CPU of this era.
I think there is still scope for something which gives a complete 'walkthrough' explanation of the operation of the Z80 based on this material. Maybe something I might start to work on!
Thanks for a very nice piece of educational software.
I never learned 8080 assembler, but I'm familiar with the MOS 6510, Motorola mc68000, Intel i860 and ARM assemblers, and with that background I could use your self-explanatory emulator immediately after reading the capitalize demo code.
Learning on the raw iron was much harder as every crash necessitated a cold start followed by loading the assembler from tape...
Does anybody know how many of these instructions still exist on the latest Intel processors?