Os8088: A powerful Mac-like OS for the IBM XT, 286, 386

More like hand-prompted...

I appreciate the topic, interest, and ambition, but if a human couldn’t be bothered to create and document it, I can’t be bothered to spend my time reading about it.

Visi On[1] was a graphical operating system for the IBM PC that actually existed as a commercial product, though definitely not a very successful one. It was made by VisiCorp, the same company that created VisiCalc (the first spreadsheet for a personal computer).

It was demoed at COMDEX in 1982, before the Apple Lisa was released. It came out after the Lisa but slightly before the Macintosh.

Here's their promotional video from 1983: https://www.youtube.com/watch?v=kc4wFeVvKTI

Fun fact: Bill Gates saw the demo at COMDEX, and at first he was skeptical that it was really running on an IBM PC. But ultimately he was so impressed he decided[2] to start developing a product called Microsoft Windows.

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[1] https://en.wikipedia.org/wiki/Visi_On

[2] https://en.wikipedia.org/wiki/Windows_1.0

> Pre-emptive multitasking on an 8086

> Twelve task slots, 1,536 bytes of stack each, and a timer interrupt that takes the CPU away from whatever is running 18.2065 times a second. No task is asked to cooperate and no task can refuse.

If you don't have protected mode, can't any program just rewrite the interrupt handler? It's not a bad system, but it sounds easy to break.

A MacOS-like desktop for the Intel 8086, written entirely in real-mode assembly (with Claude). Verified to run on real hardware, with FAT12/16 support, ported apps, games, Sound Blaster support and upcoming Hard Drive support.

It’s almost as impressive as the “GOS” written for Atari 8-bit running on 6502 at 1.79 MHz. Visually it’s almost identical but has a nicer font. The specs are somewhat similar with 16 task slots, calculator app and task manager, serial mouse support (ST mouse) and Atari’s hardware sprites helping with some of the graphics. The XOR window frame is the same idea. Amazingly, Atari GOS runs in 128K of RAM! One has to admire the work and inventiveness in these projects. See description and videos here:

https://atari8.co.uk/gui/

That said, it's not like something of this nature was thought impossible; many embedded OSes running on even slower and more limited machines (e.g. 8051) had preemptive multitasking and a primitive GUI. It just took several decades for someone with the idea, tokens, and motivation to actually do it.

I have a Pocket 8086 - I would love to give this a try next weekend.

VGA adapter means you have to wait until 1987 to run this, otherwise you'd deal with CGA's non-square pixels. EGA support would only be possible in Oct 1984.

[0] http://runtimeterror.com/pages/iv/images/b869a0cf44a7e7cbc40...