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Comment by yjftsjthsd-h | Hacker News Reader

Like, MS-DOS? How? It doesn't seem to have had an x86 CPU to run it on. (I'm assuming this predates emulation like we might use today for that kind of thing.)

Edit: Oh, kept reading the wikipedia article and found the mention of an 8086 expansion card. That's cool:)

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We had PC emulators on the 68000 based Atari ST in the 80s. No extra hardware needed, but very slow! And I'm sure that emulators was a thing from the very first computers.

Amigas as well, that is how some of my friends would do their assignments on high school.

Yeah and one of the reasons was that every byte had to be reversed due to the endianness. So it was never going to be anything but slow.

There were pc addon boards for this reason for both Amiga and Atari but they were expensive as they were basically a whole pc on a board.

I had one of these in my Amiga 500: https://www.edsa.uk/blog/the-kcs-power-pc-board (this was before the PowerPC CPUs appeared on the market, so the name wasn't as confusing as it sounds today).

In addition to being a PC board, it also doubled as a memory expansion and RTC when you were using the host Amiga system.

Mine had an 8086 too!

Some systems also had expansion cards with an x86 processor on them. A more recent example would be Sun's SunPC and SunPCI cards -- you plugged these in a SBus or PCI slot, and ran x86 code on a real x86 processor. IIRC that's actually what the AT&T Unix PC did, too, but I'm not sure (I never owned one).

See "DOS-73 Technical Reference" on the linked page for details. Yes, DOS-73 expansion cards had 8086 CPUs.

Sun also briefly made a 386 based workstation. It didn't do well, but it could run DOS via V86 in a window on an otherwise Sun desktop.

https://en.wikipedia.org/wiki/Sun386i

The ST was at least a cost-effective way to emulate a PC very slowly. Not so much for SoftPC for VMS, which cost as much as an entry-level ST for the software alone:

http://bitsavers.trailing-edge.com/pdf/dec/catalog/Digital_U...

But hey, MS-DOS 6.2 and Windows 3.1 would have at least both fit comfortably on a single TK50 cartridge or 9-track open-reel tape, so at least you weren't stuck in front of the console swapping floppies waiting for the products to install.

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