87
votes
Back in the late 1980s, how was commercial software for 8-bit home computers developed?
It varied. There was no single method. Some people used assemblers on the target machine, others used cross-development tools.
As an example of a large product for an 8-bit machine, I worked on the ...
- 9,663
56
votes
Accepted
Zilog Z80 freezes while binary counting up to 65 536 (2^16)
There are many issues here.
As it is already said in comments, decoupling capacitor is a must!
555 (non-CMOS) timer output is very much like the output of TTL ICs, however Z80 requires a firm logic ...
- 9,672
55
votes
Accepted
Did John Carmack really invent "Adaptive Tile Refresh"?
John Carmack almost certainly was the first to use the hardware scrolling capabilities of the EGA specifically, together with efficient tile and sprite drawing and erasing algorithms to create a slick,...
- 10.8k
52
votes
Why did 8-bit computers choose BASIC dialects as "de facto" command-line interface, instead of contemporary Shell/Lisp dialects?
People nowadays think of BASIC as something lesser and generally tied to puny microcomputers, but BASIC was the language of choice for many scientific, engineering and business computers in the 1970s. ...
- 195k
50
votes
Accepted
Can x86 processors run 8-bit applications?
There are several aspects to consider to answer your question.
The x86 architecture is backwards-compatible with the first CPU of the line, the 8086 (and its sibling, the 8088). What this means is ...
- 110k
50
votes
Accepted
How was the first assembler for a new home computer platform written?
Gates and Allen used remote terminal access to a minicomputer (Harvard's DEC PDP-10) to cross-assemble, and simulate, their implementation of BASIC for the Altair 8800. Commodore Basic (for the 6502) ...
- 7,924
48
votes
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Fastest 8-bit microprocessor for multiply-accumulate?
And sorry to nerd-snipe this, but of course the ideal candidate for a fast multiply-add is a Digital Signal Processor CPU, and nothing in your requirements says that DSPs are excluded. It will be also ...
- 24k
46
votes
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Why did 8-bit Basic use 40-bit floating point?
The floating-point routines for Microsoft BASIC were written by Monte Davidoff in 1975, originally for the Altair, which used an Intel 8080 CPU. The source code had been lost for years, until Bill ...
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43
votes
How was the first assembler for a new home computer platform written?
As someone who did it....
We wrote an assembler for an 8080, as there was nothing affordable from Intel.
We wrote it in ALGOL 60, if I recall, and ran it on a mainframe.
the first thing we ran ...
- 531
35
votes
Accepted
How common was programming in C targeting 8-bit processors in 1983?
How often was C used to program firmware for 8-bit processors in the early 80s?
It would have been a rather unusual choice in 1983. True, C was slowly creeping in, but only on 'big' machines and 16 ...
- 195k
33
votes
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Unlicensed home computer ports of arcade games
To understand what was going on with licensed and unlicensed ports of popular arcade games in the 1980s, you have to understand two critical factors.
The video gaming culture of the time, and the ...
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33
votes
Back in the late 1980s, how was commercial software for 8-bit home computers developed?
This had a lot of drawbacks, like the limited screen size, the slow Disk I/O, the limited RAM needed for the tools and your own code, etc.
Those are just drawbacks of having a slower or less capable ...
- 36.1k
33
votes
What made some 8-bit BASIC interpreters especially slow?
"Atari BASIC: The Good, the Bad, and the Ugly" is an excellent summary Atari BASIC's advantages and weaknesses. To answer the Atari half of your question:
How did it get so slow? Basically ...
- 3,483
30
votes
Can x86 processors run 8-bit applications?
The 8086 is source-code compatible with the 8080 (the other way around is not true). This means that most assembly code written for the 8080 can be assembled so that 8086 instructions are emitted. The ...
- 18.3k
30
votes
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Wiring a Zilog Z80
The MK 3880 Mostek CPU Technical manual (it's the Z80 implementation from Mostek) has a section called "Hardware implementation examples" which may help you.
Besides, the Thomas Scherrer Z80-Family ...
- 18.3k
30
votes
Accepted
How did old computers address far more than 64K of memory despite only having a 16 bit address bus?
I don't know details of the Sharp PC-G830 specifically but the technique used to address more than 64K with a 16-bit address bus is called "bank switching".
This involves setting up some ...
- 2,739
29
votes
Accepted
When and where did the $ convention for hexadecimal literals originate?
Short Answer:
Motorola used it for their 6800 and MOS (6500) inherited it from Motorola. After all, the 6500 team members came out of the 6800 project so they were already used to it.
Long Answer:
...
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27
votes
What made some 8-bit BASIC interpreters especially slow?
Commodore BASIC suffered from four major performance issues:
It stored numbers as text in the source, and had to parse numbers every time they were used.
Program lines are stored as singly-linked ...
- 371
26
votes
8-bit home computers without BASIC
One example of popular 8-bit computers without BASIC in ROM is the first three Atari 8-bit computers, the 400, 800, and 1200XL, which didn’t have BASIC built-in but on a separate cartridge.
Their ...
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25
votes
How was the first assembler for a new home computer platform written?
The same answer as everybody else, just with more detail:
What I mean: An assembler is not an application exactly trivial to write.
Oh, but it is. A "first" assembler on a platform simply reads ...
- 1,481
25
votes
Which microcomputer manufacturers developed their own Local Area Network systems?
One prime example is the Econet networking system designed by Acorn Computers.
Best known for their BBC Microcomputer and Archimedes systems, Acorn started with a range of modular rack-based ...
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25
votes
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What LISP compilers and interpreters were available for 8-bit machines?
To volunteer a few:
Acornsoft LISP. First released in 1982 on tape, disk and ROM chip for the BBC Micro and rereleased as a cartridge for the Acorn Electron in 1984; possibly related to the Apple II'...
25
votes
Why did 8-bit Basic use 40-bit floating point?
Using a 32 bit signed mantissa and 8 bit unsigned exponent has one major advantage: You can re-use 32 bit integer math functions for operating on the mantissa.
That re-use saves memory. It may even be ...
- 14.5k
25
votes
Accepted
Benchmark test that was used to characterize an 8-bit CPU?
There are three primary benchmarks used during this period. They are not strictly "CPU" tests, but were often used for that purpose.
The almost unknown Rugg/Feldman suite from 1977. This ...
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24
votes
Accepted
Were there any 8-bit CPUs with 24-bit addressing?
Were there any 8-bit CPUs with 24-bit addressing?
Not many. Most prominent and best fitting examples would be
WDC 65816 of 1983
Hitachi 64180 of 1985 / Zilog Z180 of 1985 (only 19/20 bit)
eZ80 of ...
- 195k
23
votes
Did any microcomputers back in the day accelerate standard-cassette performance
The Sprint cassette player/recorder, specially designed for the ZX Spectrum, allowed 4X load and save speeds.
It works by speeding up the tape four times the standard playing speed. It is meant to ...
- 18.3k
23
votes
Can x86 processors run 8-bit applications?
A few 16-bit processors can run 8-bit code: the NEC V20 series. The V20 and V30 are the ones you might encounter in a PC. The V20 is a pin-compatible substitute for the 8088, and the V30 for the 8086. ...
- 6,460
23
votes
How was the first assembler for a new home computer platform written?
The 1974 Altair 8800 kick-started the industry but at the time offered no keyboard, no screen, just a bunch of switches and lights connected directly to the bus and a counter to help you input or ...
- 33.8k
22
votes
Back in the late 1980s, how was commercial software for 8-bit home computers developed?
So, nowadays, you'd have to be crazy not to use a PC and some nice cross-development tools when targeting these old machines.
To start with, I still like to use my IIgs (or IIc-plus) when coding for ...
- 195k
22
votes
8-bit home computers without BASIC
(Please see as well other fine answers for more computers fitting the list)
I guess we can put them in four categories (in descending order of application):
Machines with Different Language in ROM
The ...
- 195k
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