82

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 BitStik CAD software for Apple II and BBC Micro systems from 1984 to 1986. That used Apple II machines with Z80 CP/M cards for coding (with WordStar) and ...


45

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) is reportedly derived from Altair Basic, and also cross-assembled using Macro-10 on a DEC 10. Woz (and many other early Apple programmers) could code 6502 ...


44

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 through it was .. itself, re-coded in assembler. Oh, and a boot-loader, though I think maybe we had already hand-assembled a minimal version of that into binary. ...


34

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 preeminence of coin-op arcade games. The role of trademarks and legal trademark protections, which was the more crucial law pertaining to arcade game ports at the ...


31

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 computer. As that was the norm, I don't think anyone thought much of it. Even considering that, a lot of that may be alleviated by a simple setup involving a ...


26

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 Official Support Page has a section devoted to circuit schematics based upon the Z80 processor. If you are in Facebook, there is a group devoted to share ...


25

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 some bytes, transforms them in a more or less 1:1 relationship to other bytes, that's it. The target architecture was very simple. There was no shared objects / ...


24

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 expandable computers known as the System range, released from 1979 onwards. These machines were aimed at serious hobbyists, researchers, and industrial users, and could ...


22

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 output sequential values. So you'd work out the binary representation of your program by hand and input it byte by byte, bit by bit. The world's introduction to ...


20

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's Owl LISP. SpecLISP. Released in 1983 for the ZX Spectrum, a subset of Stanford LISP. It wasn't well-documented at the time, so is a little obscure. Includes ...


19

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 the Apple II. Both are quite fast machines with more than enough memory to do the job. After all, editing source text doesn't get faster with a mouse and many ...


18

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 load programs originally recorded at the Spectrum ROM standard speed (1500 bps). It provides a shadow ROM that pages in when the CPU starts executing a SAVE or ...


17

It is worth remembering that by the time the home hobby microcomputers appeared, Computer Scientists had more that 25 years experience in building assemblers and designing bootstrap loaders. As a summer job in the mid-1960s, I worked as an operator in an IBM datacenter with a IBM 1401 - 16K of RAM, no disk, 5 tape drives a cardreader/punch and a printer. ...


16

The 8085, which came out two years after the 8080, rapidly became more popular for most applications because it required only +5 V power (as opposed to +5/-5/+12 V) and less external support circuitry. (Today there are a number of 8085 single-board computer designs available, such as glitchworks and OMEN; 8080 designs exist but seem few and far between.) ...


13

Caveat: I can't confirm that this works acceptably, as I haven't been able to find any references to anyone who has done it, but by reading the datasheet of the 80C88 it seems it should work there, and it may also work on an original HMOS 8088, but that's less certain as the HMOS design wasn't static (although it could work at relatively slow clock speeds, e....


13

Preface: As with many early questions, it's up to the definition of network. It might be helpful not to tie this too close to our modern understanding of a connection between (mostly) equal peers. Well known networks on the micro/home computer side may be of course Acorns Econet introduced with the Atom in 1981 Sinclair's ZX-Net introduced with the ...


13

Were there any Intel 8080 based home computers? Yes, but the number is rather small, as at the point when the idea of a home computer as we know it today (and you describe) became popular, better 'versions' of the 8080 were already available, most notably the 8085 and Z80. Importantly for low cost computer design, they did away with -5 and +12V supply, thus ...


12

They used cross-development kits back then too. I worked briefly in a UK game developer in 1990 and all their Commodore 64 and ZX Spectrum games were developed on a PC with a proprietary kit. See for example Andrew Braybrook's diary covering the development of Morpheus on the C64, where they start to use Opus PCs and an Atari ST to develop on, connected to ...


11

No, you won't need any 'HiFi' like recorders. After all, these were the very same devices you also used to record your own programs and/or data. While copying from recorder to recorder does always carry a loss in quality, this is of no big influence on a first or second degree copy (*1). The most important factor is volume. It's much the same as when ...


11

In theory, it is fairly simple duplicating a tape. The problem with analog tape-to-tape copies is that sound quality lowers and spurious noises are also copied and more are generated into each new consecutive copy generation. It did not contribute to improve the situation, that later tape copy protection methods/turbo loaders (SpeedLock, Alcatraz...) were ...


11

In It's Behind You: The Making of a Computer Game, in which Bob Pape describes his process when authoring the ZX Spectrum conversion of R-Type, alongside colleagues working on Atari ST and C64 ports, he writes: The equipment I was using to write R-Type with [initially] was the same as for Rampage, a standard 48K Spectrum with Interface 1 and microdrives ...


10

As far as the School market in Australia, the locally made Microbee was dominant in the 80's together with the Apple 2e and BBC. The Microbee was mainly sold in Australia (zero to USA) but also sold into Sweden and its neighbours, New Zealand and a few to Israel & Russia. As a result, the USA, UK, etc know very little to nothing about the Microbee. ...


10

The Intel 8080 was apparently not that popular in the West for home computers. I think it was more marketed at industrial control or whatever, but I can't say for sure. Either way, Intel soon came up with its successors, the 8088 and so on, so the plain old 8080 wasn't that common. But in the Soviet Union the KR580VM80A is basically the same thing as an ...


9

Early assemblers were either cross-assembled or hand-translated. Writing a Z80 assembler in Forth takes just a handful of screens (if you are using mnemonics based on TDL's extension of the Intel 8080 mnemonics rather than the original Zilog Z80 mnemonics). Its main job, once you are talking about a practised coder, is resolution of jump targets. To put ...


9

First note that in "real" retro computers the amount of address lines on a memory chip is generally much lower than the address lines the CPU has. This means that you won't be able to "fill" the CPU's address space without using some more logic, and, obviously, multiple memory chips. Beyond its address and data lines, every memory chip has some more control ...


9

Most of the "professional" outfits did use cross development, although they often had to build their own tools. For example they might have a Z80 assembler, but would need to make their down serial download app for the target machine to get the compiled code on there. IBM PCs and compatibles were popular for this task. There were also add-on cards for the 8 ...


8

Fortunately, for all of us, Jimmy Maher, aka The Digital Antiquarian, has been tackling your question for years and in extravagant detail and style. I would urge you to take a look at Jimmy's eBook Library, beginning with the year(s) that most directly relate to the game-play experiences you hope to recreate. All of the eBooks are broken up by year, and the ...


8

Of course, you don't need 8284 to let your 8088 run. First let see what tasks 8284 does, according to its datasheet http://www.ndr-nkc.de/download/datenbl/i8284a.pdf: It makes clock for 8088 of special shape like 1-0-0-1-0-0-... where the repeating frequency matches the specified 8088 frequency (2 to 5 MHz, according to this http://www.ndr-nkc.de/download/...


8

I'm not really sure how this question is meant, so this is maybe less of an answer as an attempt to understand the question first and answer accordingly. 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 form of memory. You may still need logic to assign the ...


8

Like others said, it varied. Lots of small developers (like Llamasoft) programmed directly on the hardware, bigger developers used other computers to act as debuggers or cross-development systems. For example, there were a lot of cross assemblers available for the Atari ST. Atari used special hardware and Vax computers to aid in development of 2600/5200 ...


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