Writing about Veskeno, it occurred to me that the nearest equivalent might not be Chifir, the Universal Machine of the Cult of the Bound Variable, Lorie’s UVM, or even Brainfuck, but rather TIC-80 and CHIP-8, or in general video game consoles:
TIC-80 is a FREE and OPEN SOURCE fantasy computer for making, playing and sharing tiny games.
CHIP-8 programs are run on a CHIP-8 virtual machine. It was made to allow video games to be more easily programmed for [01970s 8-bit RCA 1802] computers. ... In 1990, a CHIP-8 interpreter called CHIP-48 was made for HP-48 graphing calculators so games could be programmed more easily.
And Cowgod say:
Chip-8 is a simple, interpreted, programming language which was first used on some do-it-yourself computer systems in the late 1970s and early 1980s.
PICO-8 is a fantasy console for making, sharing and playing tiny games and other computer programs. ... A fantasy console is like a regular console, but without the inconvenience of actual hardware. PICO-8 has everything else that makes a console a console: machine specifications and display format, development tools, design culture, distribution platform, community and playership. It is similar to a retro game emulator, but for a machine that never existed.
The most crucial thing here is the “cartridge format”, an image file format that includes everything a game needs to run, and that the peripherals are fully specified, which is the case for Chifir but not for the UM or Brainfuck. This is true of consoles like the Nintendo, too: you can write a game and, if it works on one Nintendo, you can be reasonably sure it will work on other Nintendos too. You don’t have to worry that maybe some Nintendo can’t handle as many sprites, or runs some instructions faster and screws up the game’s timing, or has less RAM, or has a TSR installed that’s stealing cycles, or has a garbage collection that’s too conservative and causes your game to run out of memory and crash halfway through, or doesn’t interpret the cartridge format in the same way.
The challenge for Veskeno is achieving this, for a “console emulator” written by someone born after this body dies, who doesn’t have access to a working Veskeno implementation, while enabling the format to support applications that are sufficiently powerful to do things like run Linux and Windows at a speed sufficient for artifact preservation, if not everyday use.
To do this, it needs to specify the behavior of the peripherals used for the user interface at a level of detail sufficient to permit real usage; CHIP-8, for example, specifies the keyboard layout used by the COSMAC VIP, designed by CHIP-8’s author, and Norbert Landsteiner explains that the most difficult part of getting the PDP-1 emulation for Spacewar! usable was emulating the afterglow of the P7 phosphor used on the CRT, an aspect Steve Russell specifically called out for praise in his comments.