The pivotal importance of IBM's PS/2 range on computers, even today

Wed, 28 Sep 2022 20:58:30 GMT

A HN poster questioned the existence of 80286 computers with VGA displays.

In fact the historical link between the 286 and VGA are significant and represent one of the most important events in the history of x86 computers.

The VGA standard, along with PS/2 keyboard and mouse ports, 1.4MB 3.5" floppies, and even 72-pin SIMMs, was introduced with IBM's PS/2 range of computers in 1987.

The original PS/2 range included:

• Model 50 -- desktop 286.

• Model 60 -- tower 286.

• Model 70 -- desktop 386DX.

• Model 80 -- tower 386DX. (I still have one. One of the best-built PCs ever made.)

All had the Microchannel (MCA) expansion bus, and VGA as standard.

Note, I am not including the Model 30, as it wasn't a true PS/2: no MCA, and no VGA, just MCGA.

IBM promised buyers that they would be able to run the new OS/2 operating system it was working on with Microsoft at the time.

This is the reason why IBM insisted OS/2 must run on the 286: to provide it to the many tens of thousands of customers it had sold 286 PS/2 machines to.

Microsoft wanted to make OS/2 specific to the newer 32-bit 386 chip. This had hardware-assisted multitasking of 8086 VMs, meaning the new OS would be able to multitask DOS apps with excellent compatibility.

But IBM had promised customers OS/2 and IBM is the sort of company that takes such promises seriously.

So, OS/2 1.x was a 286 OS, not a 386 OS. That meant it could only run a single DOS session and compatibility wasn't great.

This is why OS/2 flopped. That in turn is why MS developed Windows 3, which could multitask DOS apps, and was a big hit. That is why MS had the money to headhunt the MICA team from DEC, headed by Dave Cutler, and give them Portable OS/2 to finish. That became OS/2 NT (because it was developed on Intel's i860 RISC chip, codenamed N-Ten.) That became Windows NT.

That is why Windows ended up dominating the PC industry, not OS/2 (or DESQview/X or any of the other would-be DOS enhancements or replacements).

Arguably, although I admit this is reaching a bit, that's what led to the 386SX, and later to VESA local bus computers, and Win95 and a market of VGA-equipped PCI machines: the fertile ground in which Linux took root and flourished.

PCs got multitasking combined with a GUI because of Windows 3 and its successors. (It's important to note that there were lots of text-only multitasking OSes for PCs: DR's Concurrent DOS, SCO Xenix, QNX, Coherent, TSX-32, PC-MOS, etc.) The killer feature was combining DOS, a GUI, and multitasking of DOS apps. That needed a 386SX or DX.

These things only happened because OS/2 failed, and OS/2 failed because there were lots of 286-based PS/2 machines and IBM promised OS/2 on them.

The 286 and VGA went closely together, and indeed, IBM later made the ISA-bus "PS/2" Model 30-286 in response to the relatively failure of MCA.

It was a pivotal range of computers and it sealed the future of the PC industry long after PS/2s themselves largely disappeared. They were a hugely important range of computers, and they introduced the standards that dominated the PC world throughout the 1990s and into the 2000s: PS/2 ports, VGA sockets, 72-pin RAM, 1.4MB floppies etc. Only the expansion bus and the planned native OS failed. All the external ports, connectors, media and so on became the new industry standards.

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The pivotal importance of IBM's PS/2 range on computers, even today