Windows 1.0 for IBM PS/2 found!
Well, it looks like these rare Windows 1.0 releases just keep coming in.
This time we finally got IBM's OEM release of Windows 1.04 for their PS/2 line. It was uploaded to Archive.org by member redruM69 (thank you!).
It comes on three 3.5" 720 kB disks. The latest file is SETUP.EXE on disk 1, dated 27th May 1987, so not that long after the retail 1.04 release. The most interesting thing about this release are of course the PS/2-specific drivers, namely the mouse and display drivers, as those are absent from the retail 1.04 release despite the readme claiming PS/2 machines are now supported.
- IBMMOUSE.DRV: this is the PS/2 mouse driver (officially designated as "IBM Personal System/2 Mouse"), which will also work on non-IBM machines with a PS/2 mouse. Using this driver in other Windows 1.0 releases instead of the Windows 2.0 driver is probably possible, and it's a more elegant solution.
- IBMPS230.DRV: the display driver for IBM's MCGA display, used in the lower end of the PS/2 line (model 30, most notably). Which is why it's called "IBM Personal System/2 Model 30". You can read more about MCGA elsewhere, but in short, it's a downgraded form of VGA that wasn't very popular.
- IBMPS250.DRV: this is the driver we've all been waiting for, it's a plain IBM VGA driver, called "IBM Personal System/2 Model 50, 60, 80" since VGA was used on more expensive PS/2 models. It also works on non-IBM machines with standard VGA cards, and in theory, should work on any 3rd party card that's VGA compatible.
- IBMPS2DA.DRV: and finally, we have the driver for IBM's more expensive display option, the 8514/A ("IBM Personal System/2 Model Display Adapter Card or Display Adapter 8514/A"). Sadly, this display isn't emulated anywhere as far as I know, though the actual card could produce a 1024x768 interlaced resolution at 256 colors. Would be definitely be interesting to see Windows 1.0 running on that.
There's nothing else note worthy in this release, aside from the mentioned drivers and it's rareness. Unfortunately, IBM didn't bother putting their logo on the bootscreen.
UPDATE: Thanks to John Elliot for pointing out that the 8514/A driver is nearly identical to the VGA one, which means it's limited to the same 16-color 640x480 display mode. Oh well...