Don’t waste money on a math coprocessor they said;

You don’t need it they said!

Well it’s been no secret, but OS/2 6.123 on my PS/2 model 80, is insanely unstable running simple MS-DOS based games (large EXE’s)

And almost always I’d get this fun error:

SYS0037: The system cannot write to the write-protected c: drive.

Followed by a crash trying to execute code at the top of the memory MAP (ABIOS?)

Illegal instruction at 0xffffffff

Then ending the program will just crash OS/2. Very annoying!

My goto test of v86 mode environments is an old game that I enjoyed as a kid, 1988’s BattleTech the Crescent Hawks inception.

Infocom’s Battle Tech

It’s a great game, that runs on many 8-bit/16-bit systems of the era, and is surprisingly a very well behaved MS-DOS game. I mean if Windows/386 VGA machines can run it in a window using the CGA version, surely a super early OS/2 2.0 beta (6.123) can run it, right? However I found 6.123 to be incredibly unstable, and sadly not up to the task.

I tried to launch BattleTech over and over and had zero success. I couldn’t figure out why it was struggling on my model 80 board, where it runs just great on 86Box. What is going on?

One thing I had stumbled upon was that if I launched an ancient Infocom game in a DOS box, and then launched BattleTech it had a much higher chance of running. But this did not always equate to it working. How is launching an old COM file from the early 80’s excise the ‘devil’ of some 1988 EXE from running?

IIT 3C87-25

I wasn’t sure but I had this weird suspicion that it was that my system was lacking a math coprocessor. When I had the model 60 286 board in the PS/2 case I did spring for an 80287, and one thing I found is that OS/2 1.0 & 1.21 ran great. As a matter of fact I think it ran better than when I used to have a 386sx-16 and then later a 486SX-20. Now it’s been closer to 30 years, so I could have an absolutely false memory of all this, but I wasn’t sure I was onto something. So while shopping around a subscriber offered me a math coprocessor as they seem to be insanely expensive in the UK. I have no idea why the 80287 was so cheap, and no idea how to make any kind of adapter, but pJok was able to score one for super cheap in his homeland and send it to the barren wastelands of Scotland. As I was wrapping up the SSD G5 fun, the coprocessor arrived, and it was time to install it!

Note the purple 80386! It’s what we might call foreshadowing

The PS/2 8580 motherboard is really oddly designed with chip orientation going in every which other direction, and the 80387 socket isn’t keyed by pin, so it’s vital to see the notches on the silkscreen. Otherwise I just used compressed air to blow out the socket, and run the reference disk to add the processor.


The processor was instantly picked up, although I had the crashing issue with the BocaRAM/2 memory card again, which meant I had to remove the RAM card, re-configure with the math coprocessor, then add the RAM card, reconfigure, then run the util to patch the CMOS so it’d boot up. I really dislike this RAM card, but 32bit cards cost far more than this entire endeavor cost so I’m pretty much stuck with it.

Now let’s compare the Landmark scores between the 286/287 and the 386/ITT387

Landmark System Speed Test with the PS/2 model 60 80286/80287

And now the 386:

Landmark System Speed Test with the PS/2 model 80 80386/ITT 80387

The ITT processor is significantly faster than the old 80287, which is pretty amazing. The system bus is running at 16Mhz, although being 32bit vs 16bit yielding a nearly 2x in performance, although the ITT co-processor is so much more efficient.

Booting back into OS/2 6.123, and yeah now it just works! No fussing around, everything is just great.

I’m kind of lost too, as none of this should require the maths coprocessor, but the results speak for themselves. I used to wonder once I got some disk images for this ancient version of OS/2, why didn’t they ship it? Sure that insane fight with Microsoft on refusing something like Windows on OS/2, or even WLO like Windows IN OS/2 from being part of the product killed any hope of running apps, but this version of OS/2 is already caught in the trap that it can run MS-DOS so well, despite DPMI not being a thing right now.

As I’d mentioned it does run just fine in 86Box, so what is the deal? Well that lead me to look back at when it did crash I noticed an odd string 038600b1

OS/2 6.123 crash screen. TRAP 000e

So what does this mean? Well looking back at the CPU let’s try to decode some of it

16Mhz 80386

First, it’s an A80386-16, which really isn’t that hard to figure out it’s a 16Mhz rated 80386. Next is the revision level, S40344. Searching around we can find this table:

S40276 - A1 (but probably 12 MHz as S40277 is 12 MHz)
S40334 - A2
S40336 - B0
S40337 is B0 stepping
S40343 - B1
S40344 is B1 stepping
S40362 - B1 (20 MHz)

So this places it at at the tail end of the introductory line of 386 processors. Checking over at pcjs, we find that there were quite a few more revisions to the 386.

And further that the B1 Errata is actually quite substantial. Maybe this is why the 386 had such a poor reputation for Unix ports in the day, and why it was shunned by CSRG?

As mentioned in the infamous 32bit multiply bug, this processor had been tested and was given the ΣΣ mark of approval. There are numerous issues listed with the presence of a math coprocessor, I have to wonder if beyond issues for using the full 32bit datapath, if there were some electrical issues with utilizing the full datapath as well? Much like an improperly terminated SCSI bus, did the simple presence of the ITT 387 help with signaling and improve system stability? Or am I hitting some weird bug in 32bit math that is simulated due to the lack of a coprocessor, that once one is in the system, the operation is performed on hardware, sidestepping the entire issue? I’m neither an EE or any good at reversing code, so I really don’t know.

The date code 751 does mean that this processor was manufactured in the 51st week of 1987.

Looking at how ancient this CPU is, I have opted to order one that was made in 1990, an SX218 or D1 stepping.

Although it hasn’t arrived yet, I have to wonder if it would make a really big difference in 32bit system stability? I have to wonder if there was such a massive delay in OS/2 2.0 because of the early 386 processors having so many defects that it just added an undue burden to the development, along with the fighting between IBM & Microsoft. While it would be interesting to see the difference between any of the Microsoft versions of OS/2 2.0, none have surfaced as of yet. Which is a shame.

Although it is nice to have this ‘mid’ IBM beta of OS/2, it does suffer from the ever so common issue of not being able to run any shipping 32bit executable, so unless you have source/object files to link, you are pretty much out of luck. The Microsoft Beta 2 tools are 16bit, so thankfully they run on pretty much any version of OS/2, and they ought to be able to run under Phar Lap 286 as well.

Microsoft OS/2 2.0 tee shirt

One thing that did recently surface on eBay, is a Microsoft tee shirt from their OS/2 2.0 group. With a minor bit of sleuthing, the Enterprise is from the 1989 ‘hit’ Star Trek V. Maybe I’m too much of a nerd to have recognized the GIF.

Back some 20+ years ago when I lived in Miami, I did have a loaded out PS/2 model 80 back then, and I ran AIX on it, as I thought it was really cool. But it was also incredibly unstable. I have to wonder now if it was a fault of the processor, or the system? Then again back then I had 6 registered IP’s and of course my PS/2 was on the internet! Although it was also the right height to double as a standing mouse pad.

So I guess this potentially leaves us with some painful lesson that you ought to get the math coprocessor for older systems if you plan on running anything other than DOS/Windows with a DOS extender. While I do have a PS/2 version of Xenix, I haven’t been able to dump them yet as my Power Mac doesn’t like NON FAT disks. One thing is for sure, it made a massive difference in OS/2. I don’t think 16Mhz/6MB of RAM is anywhere near enough to run OS/2 2.00 at any decent speed so I’ll stick with the much lighter 6.123.

32bits of disappointment, upgrading the IBM PS/2 model 60

So long..

While I had enjoyed this fully loaded 286, it was getting a bit annoying with all the 32bit limitations I was running into. Frontier Elite was a 32bit program, Obviously no WIndows/386 nor any DooM. It seems that most of the MS-DOS fun I had really was 32bit only. So with this PS/2 model 60, I did the only real thing I could do:

PS/2 80 motherboard

I swapped the motherboard with a PS/2 model 80 board. I had seen this on eBay for a bit of an excessive price, offered 40% of said price, and woke up to having shockingly won the bid. Of course it also means that I need special 32bit RAM to boot the board, because “IBM”.

a 1MB module

I picked up 2 of these 1MB modules, they are 3 chip much like the SIMMS I had used on the PS/2 model 60 motherboard. So these are no doubt parity 256k in each row, and 2 cards giving it 2MB of RAM right off the bat. I got lucky to find these 2 cards in country and at a really reasonable rate, when compared to all the others. They did make 4MB & 8MB cards, but naturally they are incredibly expensive.


Luckily for me the board & RAM worked (the board was listed as working), and running setup from the gotek was painless. However for the heck of it, I put in the Boca RAM/2 board to see if it works. It does. It also does the same thing where once the Boca RAM/2 board is configured the setup program only crashes on running it, meaning I need to disconnect the battery backed RAM.

I thought I could avoid setting up the RAM card, but oddly enough until I did so it would not initialize the SCSI card. Oh, sure it showed up in the setup program, saw all my disks and everything, but it would not boot or show up from a boot disk.

So now let’s re-visit the painful world of SCSI disks. I had bought one SCSI controller, and tore some pads off for being impatient, bought another and had it working fine with the approved cable, crashed the PS/2 MCA SCSI market, and then bought the caching faster controller card, to only reveal that it is in fact slower than the stupid card.

But it’s a 32bit card!

And now I have 32bit slots and a 32bit processor! Surely it’s going to ROCK!!!!….?

32bits of disappointment

It’s 0.3% faster.

What the actual FUCK. I mean ok BlueSCSI is great, and we’ve seen it perform faster with the ‘stupid’ card. I can’t imagine paying the $999 MSRP of this faster caching card to find out its slower. Nor the massive upgrade cost of going 32bit to find out its only slightly faster.


Just Wow.


That said, v86 mode is really cool!

My goto test for v86 is BattleTech the crescent hawk’s inception. I mean if Windows/386 can run this, everything else should be able to. And yeah, 16Mhz is almost enough to run this in a window. It screen tears like crazy and is just slow. But at least it runs!

Warning beeper music!

Although football was capable of doing this full screen in 1987, and Windows/386 could run it in a window in 1987 as well, it wasn’t until 1989/90 that OS/2 could with the much delayed 32bit version. Of course, the divorce happened after Windows 3.0 became such a massive seller, and OS/2 was delayed. again. While I had no issues under 86Box, I had plenty of weird issues on real hardware that seem to magically sort themselves out by running Infocom’s Planetfall first. I don’t know why either.

16Mhz Wing Commander

And luckily there is some difference in running at 16Mhz. Although I haven’t tried EMM386 on/off yet. The 286 had it’s excuse of copying pages in & out of protected mode, and the switch time being so horrific. But the 386 should be instant, only limited by it’s slow bus and I guess 4MB of slow RAM.

But what about DooM?

DooM v1.1 low resolution not quite postage stamp sized

Yes DooM v1.1 runs! I’ll have to try some Fast DooM later to see how much faster it can be! I’d like to think itll be faster but I am not holding out much hope.

Many of the bench stuff I had setup on the 286 to compare to the 386 sadly depend on a math processor. The problem of course is that 80287’s are very cheap for some reason. 80387’s however are not.

eBay special

And the majority of them look like this. I don’t know how on earth people have hundreds of 80287’s to sell at super cheap prices, but 80387’s all seem to have been trampled, or had their inner core’s turned into slag. I will keep a lookout, although knowing my luck it may be cheaper to find another motherboard with a 386/387 paring.

Speaking of OS/2 and weird crashes, I got this fun one from OS/2 trying to run sysinfo:

trap 000e on 038600b1

While I’d seen plenty of trapcodes in my time, but I know less than nothing about reading them. Maybe it’s burred in there somewhere. The one odd thing was the 038600b1 part… Since the 386 is a 16Mhz part, maybe it’s a crazy old version? While it does have the ΣΣ mark, maybe there is other troublesome 386’s? I really don’t know. Or maybe OS/2 is just really more sensitive to having 2MB 32bit RAM + 4MB 16bit RAM.

Way back in the old times, I had upgraded from a 12Mhz 286 to a 16Mhz 286, and life was great, although I left out of all the 32bit personal computer revolution. After a lot of hard work, I managed to secure a 386sx 16Mhz board with 4MB of RAM. It was awesome although yeah SLOW. Clock for clock, task for task the 386sx was at best the same speed. Sometimes I’d swear the 286 was faster. A few months later though I made the insane trade of some complete in box Infocom games, along with cash and was able to score a 386DX 16Mhz, along with 4MB of 32bit RAM on some massive board. Surely this was going to be great right? I found pretty much the same thing there was no perceivable difference at all. At least back then it was 1992? and the capacitor plague was still decades away, and you could just call the BBS of the motherboard vendor and download the disks if needed (I didn’t need to). It was, frankly, a big letdown after so much ’32/32 is far superior to 32/16′ and here we are again in the future and the SCSI card bears it out, that id basically didn’t matter.

I guess it really comes as no surprise that the 386 does everything the 286 can just better.

So, what have we learned? The PS/2 model 60/80 chassis is the exact same thing. The low clocked 386 chips are super unimpressive, no doubt the magic in the intel family really didn’t hit until the DX2/66 and beyond. Beta versions of software act weird, oh, and that the backup program from MS-DOS 5.00 can actually backup a dual booted OS/2 install & restore it just fine. That was a bigger surprise for me, as the great thing about the BlueSCSI i that I can have so many drives, so I made a backup of the C: OS drive and trashed it quite a bit. Not expecting anything, but yes, a restore actually worked.

OS/2 2.0 Technical Library on

It’s certainly one of those things that I’m surprised I didn’t buy when it was current, but glad binipafruc scanned the set.

PDF’s look nice on an iPad, but maybe that’s me being old.

It’s crazy that once uppon a time, corporations thought developer documentation was a revenue stream to their upstart Operating System. It went as well as you can imagine it would.

IBM OS/2 2.00 UK edition

Well something interesting and slightly different popped up, it’;s OS/2 2.00.. but in a different box, packaged for the UK market.

14G0495 – Generic Package

You have to hand it to IBM for making something amazing for 1992 so.. Bland and Generic. You really have to think there was some truth to that deal with Commodore licensing their bland grey style from the Amiga DOS 2.0 betas in exchange for a REXX.

One thing I did like about this package is the included quick reference card. I don’t recall this in the US version.

Front side

Sorry I don’t have access to a scanner here, so this is about all I can do.

Installing this was a bit of a bear, as the only thing I could boot this up in was VMware.


From a glance it pretty much looks the same as the US release, as an end user the only thing I saw different was that during the install it defaults to a UK keyboard, and Locale.

UK in the UK

I guess that is to be expected? The xr06100 fixpack installed without any fighting, so that was nice.

Sadly no stickers in the box, so it’s very underwhelming in that regard.

Ill have to look into the bootloops and crashes under qemu/bochs later. I had planned on installing it on an old machine I literally pulled out of the garbage, but it doesn’t emulate a PS/2 mouse with USB, so I have kind of put that on hold.

Anyone interested can find it here.

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.

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.

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

2ine updated to have preliminary 16-bit .exe support!

From icculus’s patreon

This is nothing short of amazing.  In the last update, 2ine was running simple 32bit programs on Linux, and providing a portable API set to allow strict OS/2 API based programs to run on Linux.

And now Ryan has turned his focus onto 16bit support for 2ine, which you can read about here:

As you can read right now It’s running a simple OpenWatcom 16bit hello world based program.  The 16bit OS/2 and 32bit OS/2 API’s ended up having different calling sizes, among other issues which had complicated the bridge program.  However Ryan’s newer use of scripts to generate the required glue for the API’s at least mean that adding the 16bit/32bit calling conventions & required bridges/glue is at least now automated.

This is super cool, as this will eventually open the door to Watcom C/Fortran, Zortec C, Microsoft Basic/C/Cobol/Fortran and of course many other languages that burst out into the initial OS/2 scene before the eventual weight of the SDK & associated costs doomed OS/2 to failure.

Seriously, for those among us who love OS/2 and have like $5 to spare, send some encouragement to Ryan… 🙂