Questions tagged [8-bit-microcomputers]

For generic questions about 8-bit microcomputers. For specific computers please use the appropriate specific tag.

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21
votes
3answers
6k views

Wiring a Zilog Z80

I've recently got hold of an old Zilog Z80 microprocessor and I know how to clock and test it. I do not however know how to connect RAM, I/O ports, control switches (for programming instructions into ...
75
votes
12answers
17k views

Back in the late 1980s, how was commercial software for 8-bit home computers developed?

When hobbyists wanted to write software for e.g. the Commodore 64, they either used the built-in BASIC interpreter (with all its limitations) or some native tools, like compilers for other languages ...
23
votes
6answers
10k views

Can x86 processors run 8-bit applications?

I was wondering if it is possible to run 8-bit applications within QEMU. I know that the x86 architecture can run 16-bit applications, but can it also run 8-bit applications?
21
votes
9answers
5k views

Intel 8080-based home computers

I'd like to build an FPGA replica of a home computer based on the Intel 8080. I am not looking to design my own computer, since I would like to tap into an existing software base. Were there any ...
23
votes
7answers
4k views

Why did 8-bit Basic use 40-bit floating point?

Nowadays floating point is usually either 32 or 64 bits, sometimes 16, occasionally 128. But of course, the Basic interpreters on the 8-bit machines, having to implement floating point in software ...
30
votes
2answers
5k views

Zilog Z80 freezes while binary counting up to 65 536 (2^16)

A few days ago, I got Z80A CPU from eBay. So I tried to run it with classic 555 timer as a clock signal generator. I connected the 8-bit data bus of the CPU to the ground to "simulate ROM" (00 for NOP)...
23
votes
9answers
6k views

Why did 8-bit computers choose BASIC dialects as “de facto” command-line interface, instead of contemporary Shell/Lisp dialects?

While all three clans of languages predated 8-bit computers, they shares features like 1) imperative programming, 2) English-alike keywords, 3) Prompt-Command-Parameters pattern interface. Why was ...
10
votes
8answers
2k views

Emulators running on 8-bit personal computers

Were there emulators running on 8-bit computers (preferably "mainstream" personal ones), available to general public (as opposed to in-house developers only)? I am mostly after emulators running fully ...
26
votes
1answer
2k views

When and where did the $ convention for hexadecimal literals originate?

I found this question asking about the origin of 0x to denote hexadecimal to be interesting. However, when I cut my teeth programming on 8-bit 65xx systems in the early 80's everything I saw used a $ ...
5
votes
4answers
2k views

How does memory addressing/mapping work in 8-bit systems?

If I attach a 16 KIB EEPROM to a 6502 or similar, and put some kind of operating system on it, it will run fine, but won't have access to any other chips. So, when a Commodore VIC20 had 5k of ram and ...