Chasing more 386 OMF

Microsoft’s first 32bit OS, Xenix

Well back before, I had been looking into old linkers for 386 OMF, I knew I’d found some fun with some old GNU tools going back to the heyday of Xenix 386. As kind of expected the tools used to build Xenix, along with it’s SDK were in fact Microsoft C/MASM. So yes way back in 1987 Microsoft not only has MASM386, but they also had a 32bit Microsoft C 5.00. Let that sink in for a moment as OS/2 had been forced into 16-bit land despite FOOTBALL, and Windows/386 being a 386 VM86 multitasker. So in a weird way all the parts were in existence.

Back in the old days of GCC 1.x there was a bit of excitement about the file masm386.c in the old GCC source directory, sadly despite it being updated, there was no real public push on modifying GCC to support non AT&T assemblers. Instead something unexpected (well to me!) happened is that GAS had been modified to output OMF.

I tested this on MinGW with some simple stuff, and sure enough it links just fine. Considering its what is on the GCC on Xenix port I’m sure it’s pretty solid.

Enter OS/2

Now this is more fun, and again kind of sad that GCC didn’t take on the ability to target other assemblers (just look at the x68000!), Maybe they didn’t see GAS for OMF, or just didn’t know. Instead a more aggressive choice was made, to alter the binary output. Linking on OS/2 with EMX involved 2 very different and incompatible paths, the first one is the ancient Unix i386 a.out format, which then a utility called emxbind will convert into a loader & stub that OS/2 can run. Think of it as an OS/2 extender to take simple Unix programs (which is what they are) to run on OS/2. Neat!

The second more ‘native’ approach is to convert the binary a.out files into what is known as OMF files, which non GNU linkers like Wlink from Watcom or Link386 from Microsoft can then link into direct native EXE’s or DLL’s.

There had been an experimental ELF build of the EMX toolchain on OS/2 but I think it may have died? So as crazy as it seems bigger and crazier programs need to be built on systems like Windows or Linux and linked outside of OS/2 to get around the old memory limits. It’s really hard to say as I’ve never used it, although being able to do the link outside of OS/2 would be an advantage.

I’ve found 2 programs to convert the a.out objects into OMF, the first and oldest being o2obj. The one drawback I’ve had is that this doesn’t play so well with the Watcom 386 OMF linker. Instead the much later RSXNT/LIBC0.6 project’s emxomf. I’ve done some painful hacking but it appears to do what it should do. A simple omfdump seems to be spilling stuff out.

Of course the alternative is to use a 64bit linker, and since a.out has been pulled from binutils the only real hope is the Watcom linker which is now running in a 64bit address space. And the Watcom chain won’t understand ancient i386 a.out, however Microsoft 386 OMF it certainly will, although it appears to be based around something later than the aforementioned o2obj, which is why I ahd to do the emxomf.

I know as this stands it’s not very satisfying but I kind of wanted to push this out the door as I’d been hacking from time to time on it, and didn’t want to leave it to rot completely. The EMX tools remind me of the NeXT stuff where everyone goes native platform wild never imagining a day when remaining portable would mean it’d be easier to target more software.

The one thing I wonder about sometimes if there was some kind of secret Microsoft extended DOS/Windows that relied on OMF & Link386 that predated the NT team and their switch to COFF? Obviously it’d be super obsolete and would have been something like the first PharLap 386 stuff. But I’ve only owned a disk dump of v4, and a legit copy of TNT v6. Old 386/DPMI/Extender tools are hard to find.

Linkers & loaders, along with binary formats are too hard for me, but I thought I’d share at least what I’d been able to conjure with MinGW. I’ll have to touch on EMX to native OMF linking later.

Citrix South Beach: aka the missing link from text to graphics

A long long time ago, in a distant continent I once interviewed at this small company called Citrix. It was some QA position, they didn’t need programmers. I’d passed the interviews easily as I’d been programming serial TSR’s so I was hip to the 8250/16450. Citrix was an interesting but troubled company. They had incredible contacts and more importantly a deal from Microsoft that gave them access to OS/2. Sadly OS/2 1.0 had been a dud, and by the time OS/2 2.00 saw even a limited release, Microsoft had pulled out of OS/2. Citrix was a company that had lost twice in what should be a big market. -Multi user commodity systems.

Citrix Multiuser 1.0 was based on OS/2 1.21, and was limited to 16bit protected mode apps. Citrix Multiuser 2.0 was based on the Limited Availability version which means that it cannot run “GA” or General Availability programs. So no 32bit programs here. Instead it can run the same 16bit protected mode applications, however it can also run MS-DOS based programs. DOS4/GW programs run so oddly enough the only real commercial stuff that can be run is MS-DOS.

So here we were 1994. Citrix had struck out twice, but this time it was going to be different, but the deal had to be re-struck again. I have no idea how they managed to secure this lucrative deal again, but Citrix was able to get access to the source access Windows NT, after the 3.1 release to 3rd parties (when they got DEC involved). By now the world had gone Windows, Office 4.2 was a thing, and on the high end side, NT had SQL & SNA, and there was most defiantly a market for multiuser systems as there had been from the old days of Unix, with the old mix of ASCII and network graphical terminals.

The CD looks like a normal-ish NT 3.5 Server CD although there is no MIPS or Alpha builds, as expected everyone at Citrix would be working and targeting the larger established i386 market.

As you can see this is Beta build 101.

In the text mode setup it looks like a normal setup program. No doubt they had better things to do than skins, wallpapers and themes. HOWEVER there is a silent IDE bug that many people will no doubt run into:

Although it works okay in short bursts, the IDE driver will send a command 28 zero byte and then shut down the controller. From this point it hangs. So that means we either need to generate all the floppy disk images (not going to happen!) or do the MS-DOS cross install. Yeah I’m doing that instead.

When setting up under Qemu, use the AMD PCNET card. It’s much easier. I set it to Twisted Pair, and PCI bus. I’m not sure if those matter all that much, but it works for me!

If you are going to use Hyper-V, you’ll need the GF100 NIC driver, but use the Windows NT 3.1 driver, as this is technically a beta of NT 3.5 and the production 3.5 driver will blue screen.

I set the driver to autosense.

I also had both Qemu and Hyper-V bluescreen when doing DHCP. I don’t know what the issue is, and I’m too old to care as I don’t have source code to South Beach, and even if I did I’d probably regret posting fixes. So static IP address it is!

Ready to login

Honestly again the air in the office when I was there is that everyone was running around like crazy to QA the product, and get ready to expand client support. While I was too much of an OS/2 fan boy, they certainly knew that from now on everything was going to be about Windows NT.

Logging into the Citrix the first fun thing to do is to define some remote terminals, using the WinStation app.

The first interesting thing is that async terminals are supported. Along with using either NetBIOS or Winsock protocols for connecting clients. Isn’t that great! TCP/IP built in!

Now for the crazy part. The only client that works is MS-DOS based. Yes there is no Win16, no Win32, no Java, no protected mode DOS, no Linux, SunOS, Solaris, DG/UX, AIX, HPUX, Xenix, UnixWare or SYSV i386ABI. ONLY Real Mode MS-DOS. Despite the connections being able to be ICA version 2 or 3, they are incompatible with newer Windows based clients from Win Frame.

This it the following list of supported protocols. Although I had Novell Lan WorkPlace and used it before for Desqview X, I can’t find it at the moment. good luck finding FTP TCP/IP, in retrospect it’s a terrible name, and for all intents and purposes it’s disappeared from the earth. So that leaves Microsoft TCP/IP. Now all the LANMAN clients have it, although this isn’t what it wants. It wants the MSCLIENT found in the “\CLIENTS\MSCLIENT\NETSETUP” path from a retail version of NT Server 3.5

The DOS client is.. very touchy. Deleting profiles can lead to a corrupted profile. Altering existing profiles well yeah can lead to a corrupted profile. I thought it was EMM386 causing issues but it locks up on it’s own.

Revenge of text mode UI

One interesting thing I found is that the text mode UI didn’t die. It’s still very much alive. As mentioned above you can connect async terminals, or even connect over the network!

Text mode does bring up a Program Manage analogue, but all my programs are graphical so it’s kind of moot. But rest assured text mode stuff works great.

PowerStation Oregon Trail

So 32bit Fortran stuff works great, what about MS-DOS?

Here is MS-DOS / Qbasic editor. Running on Citrix South Beach! Great, what about OS/2?

OS/2 F2C Dungeon

And here we go running the f2c translator through Dungeon to get an OS/2 text mode app. As you can see forcedos reveals that this isn’t a bound executable, instead it only runs on the OS/2 subsystem.

As you can see the os2.exe/os2srv components of the OS/2 subsystem

And of course it looks better on the graphical client to mix and match them all.

Win32/Win16/OS/2 all at once!

Indeed Word & Excel for NT work great alongside everything else.

Obviously somewhere post South Beach the text mode stuff dropped off. I’ll have have to dig for more, but it’s kind of neat the idea of a real text mode NT. Sadly South Beach doesn’t seem to like VMware. I haven’t dug too far, as I like WSLv2 so I’m stuck with Hyper-V. It may work fine on ESX I haven’t tested. Obviously you need the appropriate drivers, ill try to update links later, if anyone cares.

No doubt that finally Citrix was no positioned to realize the dream of multiuser commodity based hardware along with commodity applications. Of course it wouldn’t be all sunshine and rainbows, and no doubt there was a toll needing to be paid between Windows NT 4.0 and on the way to Windows 2000. But back in 1994, things were looking good!

IBM OS/2 J2.1 Beta Release (aka 90’s CD-ROM done right)

Frustration of the early 1990s

Something that used to annoy me to no end back in the early 90’s was nearly empty CD-ROM’s from big companies. Back then dialup was the norm and I was ‘lucky’ enough to have a 2400 baud modem back in 93. I wanted a 32bit processor and at least 4MB of ram to join that elite home based 32bit computing to finally feel like I’d upgraded well beyond the Commdore 64, but money was tight and that 2400 baud modem I got on sale from BrandsMart USA was ‘good enough’. I’ve had a 300 baud modem on the c64 so I knew the feeling of absolute painful downloads.

Heck internet access wasn’t so prevalent, and dialing up to BBS’s was super common. It’s a BBS where I stumbled across Linux on CCUG, which was both great for being local but also letting me download at night at 2400 baud as many BBS’s kicked me for being too slow. Thanks Doug!

But here we had this awesome era of CD-ROMs, I managed to snag a NEC Intersect single speed external from TigerDirect, who would have these annual sales to clearance all kinds of RMA’s. It was a great time to get stuff for pennies on the dollar as they say. It was amazing to have access to nearly 700MB of data per disc. But it was amazing how empty so many were.

One such opportunity to ship as much as possible to the users was absolutely missed in OS/2 2.1/3.0 Looking at the EN-US release you find the OS/2 2.1 for Windows CD-ROM contains just the OS, both extracted and disk images:

Volume in drive E is OS2_CD_ROM
  Volume Serial Number is 4384-1BD8
 Directory of E:\
 [DISKIMGS]    [MMPM2]       OS2SE20.SRC   [OS2SE21]
                1 File(s)             10 bytes
                3 Dir(s)               0 bytes free
 Total Files Listed:
          645 File(s)    292,279,546 bytes
          135 Dir(s)               0 bytes free

with 300MB on the disc that left space for another 300MB. What could they have put on there? Obviously the best answer is 3rd party drivers, any and all SDK (Although we are talking about IBM who famously priced the OS/2 1.0 SDK for $3,000), demos, utilities, free software?!

Enter OS/2 2.1J Beta of Japan

While on the Discord some cheap OS/2 CD-ROMS popped up and @plaman was nice to image them for me. I was more interested in Borland C++ 2 for OS/2 but there was also this Japanese beta of 2.1. Normally I wouldn’t be all that interested as I was thinking it was for PC-98 but but’s the ‘DOS/V’ variant which is mostly like a normal PC. But mounting the CD-ROM showed it was far more interesting:

Volume in drive F is V_MAG9310
  Volume Serial Number is DD59-9766
 Directory of F:\
 [DOS_WIN]     [OS2BETA]     [OS2DEMO]     [OS2FREE]     OS2SE20.SRC   [OS2SUPP]     [PCGAMES]     README.1ST
                2 File(s)          2,187 bytes
                7 Dir(s)               0 bytes free
 Total Files Listed:         2867 File(s)    501,115,944 bytes
          637 Dir(s)               0 bytes free

PC Games?! Demos?! What is this! And sure enough it has a tonne of game demos including a bunch of Sierra, LucasFilm and even an Electronic Arts Syndicate demo!

Leisure Suit Larry Demo
Indiana Jones and the Fate of Atlantis Demo

In the freeware directory its a selection from Hobbes, including EMX 0.8F, and the GCC/2 port. Also hidden in there is ‘S_O2OBJ.ZIP’ which is the source to a program to convert GAS i386 a.out object files to OMF for use by LINK386 (yes that adventure is ongoing), and all kinds of other fun things. What is nice is that the source code archives are included as well. Thanks IBM of Japan!

In addition there is of course one of those ‘OS/2 demo’ slide show apps

Very AmigaDOS 2.0

It’s just a simple slide show thing to go over how to use the new desktop

Transform your ‘old’ desktop to the new metaphors of the past:

Into the OS/2 future! Of course you have to understand it’s 1993 by now, and the vast majority of the world is using either Windows 3.0 or 3.1. The new OS/2 2.00 UI is so radically different that even Windows 10 doesn’t attempt the same level of object integration. Although leaving it like the above would be more of a ‘Bob’ type of move, the real world result was this:

Of course in the demos the backdrop per folder thing in OS/2 always looks great, but in real life it was never the same. Perhaps it was the limitation of editing tools of the time, or how OS/2 had a different bitmap format from Windows, which really limited the ability to interchange images.

Compare this to the clutter of the Windows 3.0/3.1 desktop:

Obviously the ‘winning move’ was the Windows 95 desktop which reduced icons to mere shortcuts to give the illusion of something like the OS/2 desktop, but without anywhere the level of complexity and integration made for something far more lightweight. Of course I don’t even want to talk about the binary ini files, their ability to corrupt and booting off diskette to rebuild the desktop by hand. When things failed on OS/2 they failed in the most amazing ways.

At the end of the day;

I still haven’t tracked down a release version of OS/2 2.1 for the Japanese market to see if the CD-ROM version shipped with anything beyond the OS. Perhaps it was simply a beta thing. But these shovelware discs always have a great accidental archives of the era. And it’s nice to see that some OS/2 stuff got preserved for once.

If you are interested you can download the ISO on here: OS2J21_Beta

Ultra rare IBM OS/2 ad featuring OS/2!

I honestly didn’t think anything like this existed

Stay 2'ned. Can't help but think of 2ine.

Presentation Manager for Windows NT

This is something that honestly deserves so much more. Back in the original scope of NT OS/2 it was going to be a C parallel of OS/2 2.00 Cruiser that had the promise of running on one of those new fangled microkernels, and those trendy RISC workstations. The 486 / Pentium were considered like the 68040/68060 to be the peak of CISC processors and from there on it was going to be a RISC world, the only question was to be which one?

Many of the Motorola customers who couldn’t afford to make their own (SUN with the SPARC), or license a school project (SGi with MIPS) were expected to use the 88000 processors that were expected to eclipse the 68040. There was an Apple initiative, and even a NeXT RISC Workstation built among many others. Only with the launch of the 88010 it was discovered performance was nowhere near expected and it’d take significant work to fix.

Back on the i386 side, Microsoft had been working with Intel on their upcoming RISC, the NTen aka i860. And just like the 88000 it too had performance issues, which resulted in Microsoft retargeting the MIPS.

Things changed along the way, and not only was the primary CPU platform dumped, but Windows 3.0 became such an incredible seller that OS/2 Cruiser was dumped from NT OS/2, and it became Windows NT. NT had been promised with the ability to run OS/2, MS-DOS, and POSIX applications, with an emphasis on Win16 and the new extended Win32 applications. However MS-DOS was super limited, POSIX was just enough to run vi & tar, Win16 was incredibly slow as it ran through WOW (Windows on Windows), and OS/2 had been kneecapped to the 16bit 1.x support as it was primarily a vehicle for running Microsoft SQL Server 1.0/4.0 . Another consequence of this is that OS/2 was command line only. In the back of deployment guides, and resource kits there was always an inference to a Presentation Manager subsystem for NT, although I’d never seen one in the wild.

Until I got a hold of a bunch of Microsoft Select CD-ROM’s that mostly were multilingual service packs of Office and Windows 98 / NT 3.51 & NT 4.0 But burred in there was a copy of Presentation Manager for NT 3.51!

First off it’s a text based install. It feels like October 1991 all over again. It installs a parallel OS/2 directory with presentation manager support.

Once it is installed it’ll setup program icons from the Windows NT side. Presentation manager runs in a separate window from the GDI. This is akin to how OS/2 would run Windows in a ‘full screen’ session. So oddly enough both support each other’s 16bit applications full screen, while reserving the desktop for 32bit applications. IBM would later introduce dual mode video drivers capable of rending Windows and OS/2 applications at the same time. Clearly Microsoft would never do this.

Launching the control panel reveals that it’s OS/2 version 1.3. No big surprise there. You can return to the Windows NT desktop either via the Windows NT icon in the bottom right, or via a Control+Alt+Delete.

The DeScribe 3 beta installs pretty smoothly into the subsystem. However running Describe is a different story:

It hangs trying to open or do anything. Even the ‘help about’ is too much. Such a pitty.

The readme warns against trying to copy the file manager from OS/2 although it does tell you what files to copy in manually. Naturally there is no ‘console’ for Presentation Manager, rather that is handled on the Windows desktop.

No doubt there had to be some big customer that demanded a way out for their investment in Presentation Manager on Windows NT. Otherwise this would have been built in. And it’s only 5 diskettes so it’s not a space issue. I suspect since it was on a Select CD, it really was not meant for wide scale distribution.

Last time I tried, Excel 3, and Word 1 had issues running on Windows NT, as the loader tried to intercept them as Win16. Things didn’t go so well. Or maybe it’s my memory. I went ahead and installed Excel 2.2 for OS/2

Despite it being text mode, it has Presentation Manager hooks, and needs PM Shell to be running. It’s a simple setup program, but yes, it’s text mode.

One nice thing about Describe & Excel is that they can see the program groups on the NT side, and create icons over there. However NT has no ability to read OS/2 resources so the icons are all incorrect.

And yes, Excel for OS/2 runs on Windows NT! Back then Excel was super expensive, this is before the big Office OEM bundles that took over the industry. So I could totally see preserving this massive investment in Excel.

Despite having 80286 emulation in the earlier versions of NT, and 80486 emulation in Windows NT 4.0 (Yes DooM runs on the MIPS!) the OS/2 subsystem was never available on the RISC platforms. I suspect had Windows 3.0 not been a big seller it may have. Then again without the big ‘rabbit out of a hat’ like DOS Extenders, Windows would have died on the vine. Who knows, maybe NT OS/2 is a thing in a parallel universe.

All in the Family

One of the more interesting things about OS/2 1.x is how it had this interesting idea of how to strattle the bridge between old and new, and it was a very common bridge tactic where you can have a shipping program that can simply run in both the older operating system, and the new one. Naturally there is trade offs, you can’t fully take advantage of all kinds of features on the new side, you will be largely held back on the old side, but all is not lost, there is space for things that fit in the ‘same but bigger’ world where you have an overlap between old and new.

For OS X, this was the Carbon era, for Windows this was the famous Win32s extensions, and for OS/2 it’s the Family API.

As a quick example, allocating memory under MS-DOS may be limited to 640kb, but under OS/2 you have access to so much more memory, the entire capacity of an IBM AT class machine. And this also got OS/2 tools into a lot of MS-DOS developer’s hands as the early compilers and tools were built around the Family API and were able to run on so called legacy environments. Although it was far better to run on OS/2, the advantage 30+ years later is that MS-DOS emulation is more common and prevalent than OS/2, especially on non x86 processors.

Ages ago I had done a very simple video memory dump of the Microsoft Programmer’s Library giving me electronic access to the old documents, and a few queries give these as the Family API building blocks:


  • DosAllocHuge
  • DosAllocSeg
  • DosBeep
  • DosBufReset
  • DosCaseMap
  • DosChDir
  • DosChgFilePtr
  • DosCLIAccess
  • DosClose
  • DosCreateCSAlias
  • DosDelete
  • DosDevConfig
  • DosDevIOCtl
  • DosDupHandle
  • DosEnumAttribute
  • DosErrClass
  • DosError
  • DosExecPgm
  • DosExit
  • DosFileLocks
  • DosFindClose
  • DosFindFirst
  • DosFindFirst2
  • DosFindNext
  • DosFreeSeg
  • DosGetCollate
  • DosGetCtryInfo
  • DosGetDateTime
  • DosGetDBCSEv
  • DosGetEnv
  • DosGetHugeShift
  • DosGetMachineMode
  • DosGetMessage
  • DosGetVersion
  • DosHoldSignal
  • DosInsMessage
  • DosMkDir
  • DosMove
  • DosNewSize
  • DosOpen
  • DosPutMessage
  • DosQCurDir
  • DosQCurDisk
  • DosQFHandState
  • DosQFileInfo
  • DosQFileMode
  • DosQFSInfo
  • DosQPathInfo
  • DosQVerify
  • DosRead
  • DosReallocHuge
  • DosReallocSeg
  • DosRmDir
  • DosSelectDisk
  • DosSetDateTime
  • DosSetFHandState
  • DosSetFileInfo
  • DosSetFileMode
  • DosSetFSInfo
  • DosSetPathInfo
  • DosSetSigHandler
  • DosSetVec
  • DosSetVerify
  • DosSizeSeg
  • DosSleep
  • DosSubAlloc
  • DosSubFree
  • DosSubSet
  • DosWrite


  • KbdCharIn
  • KbdFlushBuffer
  • KbdGetStatus
  • KbdPeek
  • KbdSetStatus
  • KbdStringIn


  • VioGetBuf
  • VioGetConfig
  • VioGetCurPos
  • VioGetMode
  • VioGetPhysBuf
  • VioGetState
  • VioReadCellStr
  • VioReadCharStr
  • VioScrLock
  • VioScrollDn
  • VioScrollLf
  • VioScrollRt
  • VioScrollUp
  • VioScrUnLock
  • VioSetCurPos
  • VioSetCurType
  • VioSetMode
  • VioSetState
  • VioShowBuf
  • VioWrtCellStr
  • VioWrtCharStr
  • VioWrtCharStrAtt
  • VioWrtNAttr
  • VioWrtNCell
  • VioWrtNChar
  • VioWrtTTY

I’m sure this is not exhaustive by any stretch. I got the list from a simple query like this:

grep -i 'family api' os2dev.txt | awk '{print $2}' > fam.txt
grep -i 'family api' prgmr[34].txt| awk '{print $3}' >> fam.txt
sort fam.txt | uniq > family.txt

As an added bonus you really don’t have to mess with the API at all, as the LIBC will use it no doubt.

At any rate, using Microsoft C 6.00 (I can’t get the syntax right for 5.1 to save my life, I suspect I need to run it UNDER OS/2 to build for OS/2 properly), you can compile a typical stdio compliant program, and get an OS/2 executable.

The real fun is from the bind program which will convert that OS/2 program to a full Family mode app with the bind program.

And now on MS-DOS (Under OS/2) you can see very quickly that the OS/2 app won’t run, however the family mode one does!

So this is what let’s me run the older SDK tools as I’d simply forgotten about this great mode, letting you run programs in either environment.

Of course the added fun is the 3rd party product Phar Lap’s 286|Dos-Extender that provides some OS/2 services under MS-DOS in addition to greater memory but DLL’s! But that’s for another story.

**EDIT Oh and another edit, here is how to make the OS/2 program ‘window’ compatible with a link time definition file:

OS/2 2.00 via telnet

and then on the console:

Window mode

And there we go with some magical flags & def file it’s now marked as being compatible with window mode. So no full screen VIO tricks for you!

Wlink-ing for fun & … profit?

well rounding out the experiment is of course the hidden OS/2 2ine. And how does it respond to the various linkers?

Operating System/2 LX (Linear Executable) Linker
Version 2.00.000 Mar 20 1992
Copyright (C) IBM Corporation 1988-1991.
Copyright (C) Microsoft Corp. 1988-1991.
All rights reserved.

If you remember this is from the Limited Edition or Citrix Multiuser 2.0 version:

$ ./lx_loader /mnt/c/msos2/test/mt.exe
mmap((nil), 8192, RW-, ANON|PRIVATE|FIXED, -1, 0) failed (1): Operation not permitted

What about the OS/2 2.0 GA linker?

[<ohestwo>-C:\TEMP]\os2\link386 mt.obj

Operating System/2 Linear Executable Linker
Version 2.01.005 Mar 16 1993
Copyright (C) IBM Corporation 1988-1993.
Copyright (C) Microsoft Corp. 1988-1993.
 All rights reserved.

Run File [mt.exe]:
List File []:
Libraries [.lib]:
Definitions File [nul.def]:
LINK386 :  warning L4071: application type not specified; assuming WINDOWCOMPAT



and on 2ine?

$ ./lx_loader /mnt/c/msos2/test/mt.exe
not an OS/2 module

Well this all sucks. But how about a 3rd party linker? Watcom?!

C:\msos2\test>cl386 /c mt.c
Microsoft (R) Microsoft 386 C Compiler. Version 1.00.075
Copyright (c) Microsoft Corp 1984-1989. All rights reserved.


C:\msos2\test>wlink d all SYS os2v2 op m op maxe=25 op q op symf @mt.lnk

C:\msos2\test>dir mt.exe
 Volume in drive C has no label.
 Volume Serial Number is 3C41-1D63

 Directory of C:\msos2\test

13/05/2021  01:48 am             5,160 mt.exe
               1 File(s)          5,160 bytes
               0 Dir(s)  646,855,708,672 bytes free


and on 2ine?

$ ./lx_loader /mnt/c/msos2/test/mt.exe

Wow! How about OS/2 2.00 GA?

Sadly a no go.

Obviously this needs more testing on later versions of OS/2. I tried wlink from Watcom C/C++ 10.0 and it won’t run. Once more again the devil is in the linker, and just as last time, it turns out that the ‘portable’ tools are 16bit!

$ ./lx_dump /mnt/c/msos2/bin/orig/CL386.EXE
NE (16-bit) executable.
Linker version: 5
Linker revision: 2
Entry table offset: 117
Entry table size: 2
CRC32: 0x30E8EA59
Module flags: MULTIPLEDATA
Application type: WINPMCOMPAT

I meant to post earlier but if you want to follow along, project dump is msos2-wlink.7z.

Continuing with Ancient Microsoft C/Linkers

Microsoft OS/2 Software Development Kit Pre-Release 2

I don’t know why, but Microsoft OS/2 2.00 beta’s are beyond rare. At one point I had a documentation set but not disks. However disk images circulated around, so at one point I did have printed documents (that basically didn’t show much interesting other than True Type fonts for OS/2), and the SDK/ToolKit. However there to date has been no operating system images surfacing.

Since yesterday’s look at the 1991 Windows NT Pre-release which turned out to be using the OS/2 compiler, I went back and checked the Microsoft OS/2 SDK, and it turns out that the compiler is a ‘bound’ executable, meaning that it’ll run under MS-DOS!… And for us that means the MS-DOS Player can make native Win32/Win64 executables out of the compiler/assembler.

Microsoft (R) Microsoft 386 C Compiler. Version 1.00.075
Copyright (c) Microsoft Corp 1984-1989. All rights reserved.

As always the devil is in the details, and this time it’s the linker. I now have OS/2 2.00 v123 (February of 1991), Citrix Multiuser 2.0 (March 1992), and OS/2 2.00 GA (July 1993). And not surprisingly despite them all either including a system link386.exe or the SDK link386 they have massive final incompatibilities.

For fun, I’m using a super simple C program, and compiling it with the Microsoft Pre-Release 2 SDK. After that I’m just using various Linkers & OS’s and the same Pre-Release libraries to see the same object relinked and running.

void main(void){

It’s a very simple program that really doesn’t assume or need much other than write.

So looking at OS/2 build 123

Version 1.01.015

This is the SDK Linker 1.01.015. Dated November 28th, 1990. Which sounds a bit late in the year, but don’t worry as the OS includes Version 1.01.018, dated August 15th 1990!

Version 1.01.018

I don’t understand it either.

Citrix Multiuser 2.0

Version 2.00.000

Citrix Multiuser is using the 177H base also known as the OS/2 2.00 LE. It includes a version 2.00.000 linker, which works fine for it. However the SDK and 123 linked files do not run. While the SDK runs fine, I don’t know how did they link the tools as they work fine**.

OS/2 2.00 GA

Version 2.01.005

And finally we have OS/2 2.00 GA using it’s linker, and yeah it runs fine. Also the GA can run the LA linked files. Naturally 123 can’t run either LA or GA EXE’s.

Obviously the tool group was separate from the OS teams, and there was that brief window when everything 32bit was OMF, and LX was going to be the grand behind the doors unification thing providing 32bit exe’s for Windows 3.x VXD’s, OS/2 2.x and Windows NT. But as was obvious in the 1991 Pre-Release the tool to convert OMF to COFF wasn’t going to be a tool much longer and it was going to be integrated directly.

I’ve tried using the link386 from the Windows 3.1 DDK but I can’t get it to link properly. Just as I haven’t tried other MASM386’s or even 16bit MASM 5+ which apparently support 32bit OMF?

Again it’s interesting to me, but is it useful? Not really. Also the last interesting bit is that the Microsoft C from the 73g build of the Windows 95 SDK can produce assembly that the Pre-Release more or less understands:

D:\OneDrive\proj\link386>4.00.73g\BIN\cl /c /Famt.asm mt.c
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 8.00.3200
Copyright (c) Microsoft Corp 1984-1993. All rights reserved.



And then assembling and linking on OS/2

Useful? Not very. I don’t think anything complicated will run, although I have only tried one thing and it had a tonne of 16bit/32bit collisions. I don’t know if Microsoft C/C++ 8.0 for OS/2 is all that desirable but I’d imagine if it were, smarter people than I would have made it a thing.

**Edit from the future

Well it turns out the SDK tools are 16bit Family mode apps. It’s obvious once Nathan pointed it out that there is no 32bit ‘bound’ for MS-DOS, however there was Family Mode*** for realmode/protected mode 16bit code.

DOS/4G error (2300): can’t find DOSCALLS.282 – referenced from MT
DOS/4G fatal error (1313): can’t resolve external references

PharLap famously made their early 286 extender based around OS/2, however for the 32bit stuff it was apparently home grown for the early stuff (I have version 4) but there is DLL’s to emulate MS-DOS like the 286 extender. Interestingly enough DOS/4G supports DLL’s but again there is no DOSCALLS.DLL I can find, but the loader loads it.

***Family Mode/Family API

From the book INSIDE OS/2 (ISBN 1-55615-117-9): Family API
To provide downward compatibility for applications, OS/2 designers
integrated a Family Applications Program Interface (Family API) into the
OS/2 project. The Family API provides a standard execution environment
under MS-DOS version 3.x and OS/2. Using the Family API, a programmer can
create an application that uses a subset of OS/2 functions (but a superset
of MS-DOS version 3.x functions) and that runs in a binary compatible
fashion under MS-DOS version 3.x and OS/2. In effect, some OS/2 functions
can be retrofitted into an MS-DOS version 3.x environment by means of the
Family API.

Interesting? Maybe. October 1991 NT SDK uses the OS/2 toolchain

The linker is from an older MS SDK, the compiler from October 1991 preview of NT

So back in the day I wrote something vague about the October 1991 preview version of Windows NT, and after messing with the tools and building f2c & dungeon (among some other stuff) one that that stuck out to me is that the object files had to be converted for NT.


The interesting thing is of course that it doesn’t support the cl386 direct compile and link (hence CL). Instead you have to compile, convert and then link. A fun thing about the October 1991 version is that there is a cl386 cross compiler for OS/2. So while looking around for OMF linkers (and assemblers that either understand GAS but output OMF, or some translator) I ran across this, and well yeah, it turns out that the OS/2 tool chain is the toolchain. I guess it makes sense in that the NT team was using OS/2 to build NT, but objects and exe’s were not solidified.

I think 6.00.080 was the last version of Microsoft C 386 for OS/2. I need to start collecting more of the SDK/DDK’s of the mixed era, I think the LX/OMF stuff was a bit more widespread hiding in plain sight.

Anyways, interesting?! sure. useful? Maybe 30 years ago. Although I’d probably say just use Watcom C/C++ instead of Microsoft C 6.00

Early MSDN CD’s on

I ran across this, and thought it was cool. These CD’s are getting harder and harder to find, and unless you want the old physical disks, getting ISO images is, of course the next best thing.

Granted these disks replaced the much older Microsoft Programmer’s Library. The new CD’s use a Windows based search & interface program removing the clunky old MS-DOS program that made it feel like trying to view the world through a straw. (Although the up side of the MS-DOS version is that you could easily dump the video RAM and save the contents to plain text).

And in this brave new post Windows 3.0 centric world of Microsoft just about everything regarding OS/2 was dumped, and the seeding of Win32 via Windows NT had started.

Naturally after winning this war, Microsoft withdrew many low end products and just couldn’t compete with the tidalwave that was GNU/Linux.

At any rate for the curious kids down the road that want to see what all the fuss was with Win16, and how Windows 3.0 had changed the landscape removing the force of IBM it’s worth a look.