OS/2

From Computer History Wiki
Revision as of 07:29, 11 February 2009 by Neozeed (talk | contribs) (This is a quick version from memory, it needs pictures and stuff.)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

OS/2 started as a collabrative effort between IBM and Microsoft to put together the next generation Operating System for the IBM AT and above.

Microsoft, famous for hedging bets, started the Windows project around the same time.

Needless to say Microsoft wanted to target the 386 processor, and work on 32bit software, while IBM wanted to deliver to the IBM AT customers it had sold to, and demanded the 286 16bit version. Someone at IBM even got the idea that the development tools should be a revenue stream, and needless to say, the $3,000 SDK was *NOT* a big seller. Instead the industry worked around OS/2, and developed DOS Extenders technology.

Microsoft, lept at the chance to formalize DOS extenders into DPMI, and use it in Windows, cementing OS/2's 1.x inability to run DPMI programs. Microsoft was also upset that IBM locked them out of the graphical components of the OS, and that OS/2 worked BACKWARDS compared to Windows... the 0/0 in the screen coordinates is the bottom right, while everywhere else it's the top left..

There is a great writeup on the divorce on google's usenet archive:

http://groups.google.com/group/comp.os.ms-windows.misc/msg/d710490b745d5e5e

Versions

  • 1.0
  • 1.1
  • 1.2
  • 1.3
  • 2.0
  • 2.1
  • 2.11
  • 2.11 SMP
  • 3.0
  • 4.0
  • 4.5

PowerPC port

It's a deep secret that the PowerPC version ended up sucking up so much time, effort and money from IBM's development of OS/2, that it ended up bleeding the group dry, and without a product to ship. IMHO it's a shame, as partnered with the PowerPC 615 CPU it could have revelutionalized the industry.. But then back then everyone expected Intel to hit a wall, IBM had the 615 in their pocket which was a PowerPC CPU which was pin compatable with a 486, and could run x86 code (albeit slow..) and then switch to PPC mode. The company NexGen opened up everyones eyes that a specialized RISC cpu could infact run x86 instructions much quicker then a real Intel cpu... This opened the way to the Pentium CPU's and effectivly killed the RISC revolution.


Running OS/2 under an Emulator

16 bit versions

The only version of OS/2 1.x that can run under an emulator is 1.3 with all the updates applied. The three problems that you will run into is emulated floppy disks are too quick, and other various timing anonmolaies that will lead to a COUNTRY.SYS failure. The last major hurdle is the method of switching from protected mode to real mode. Prior to the last fixpack for OS/2 1.3 the method was a tripple fault. None of the emulators can accuratly reproduce a tripple fault. However with the fixpack, it will use the 386's normal method for switching between modes.

The method for install requires you to install OS/2 1.3 on a physical machine, update it, then make a whole disk image of it. I can confirm that OS/2 1.3 runs under Virtual PC 2007 just fine.

32 bit versions

I've run OS/2 2.0 & 4.0 under Virtual PC, and Qemu... I guess it really comes down to if you move disk images around between various hardware platforms. Anything prior to version 3.0 should be run in an ISA emulation mode (-M isa) to let the periphials work in a more compatable manner... Virtual PC 2007 works fine as well, and includes extensions that allow the guest VM to use drives that are installed on the host pc. I've heard that VMWare has given up the compatability mode fixes.

Qemu Virtual PC 2007