2 Model 60

Posted on February 24, 2024 by neozeed

Don’t get me wrong, it’s a very 1980’s awesome machine. Aesthetically. But practically? No way, it’s a legit white elephant. And it killed OS/2 before it even became a thing. I know what about the JDA, and IBM interference? What about the poor choice of the 80286 processor? What about DOS Extenders? YES it’s all there, Half an Operating System, for Half a computer, the real reason OS/2 failed, and it’s wrapped up in a 20 x 8 x 18 inches package weighing in at 40 pounds.

Behold the IBM PS/2 model 60.

The PS/2 model 60 from the OS/2 1.0 brochure

The base model PS/2 60 with the 44Mb hard disk was priced at an eye watering $5,925 in 1987. And to be clear that is with only has ONE megabyte of RAM which is nowhere near enough to even boot OS/2. Realistically, you would need the additional memory card, and another 4MB of RAM, raising the price far higher, as stated in the requirements for the sales demonstration of OS/2.

The realistic OS/2 requirements, 5MB of RAM!

The 77Mb disk system would set you back $6,295, again not counting the needed memory upgrades.

It’s BIG, loud, expensive, and more importantly obsolete on day one.

Going back, to the original success of the IBM PC and it’s open architecture lead to the one big issue, which is that it was trivial for people to clone, as they published everything you’d want to know in their technical reference manuals. The one thing that was copywrite was the BIOS. However as I’m sure everyone heard the story of how Columbia Data Products released the MPC 1600, which set the gold standard on reverse engineering, but opened the floodgates to bigger players like Compaq, and ushered in the clone revolution.

IBM was obviously not happy with this. IBM always looked to hardware for money, and IBM build quality, and of course that lead us to the PS/2. There is no way they could have developed this in the space of a year, which again if it took 2-3 years to bring them to market, it would explain so many of the missteps of the Model 30 which both had an ISA bus, and had either an 8086 or 80286 processor. This may have been okay for 1985, but they were far too old & slow for 1987. Many people have cited that part of the PS/2 revolution was the new bus on the model 60/80 Microchannel which unlike ISA had to be licensed from IBM, but of course it didn’t catch on, instead it gave confidence to the industry to not only set out on their own 386 machines, but then their own 32bit bus EISA. Yet another reason the 8086/80286 machines should never had existed.

$5,795 MSRP for the IBM AT – InfoWorld 3 Dec 1984

Looking back to December of 1984 we can see the MSRP for the 6Mhz IBM AT was $5,795, the AT model 099 included a whopping 20MB hard disk, a single high density 1.2MB 5 1/4″ floppy drive, and 512kb of RAM. Now jump forward a few years, and every clone manufacturer has benefited from economies of scale as the commodity parts increase of demand and sourcing has only led to lower prices. Except for IBM. While the Model 60 does have twice the RAM going up to a base configuration of 1 megabyte, and a 44MB hard disk, the price is $6,995 or a 20% price increase!

What lead to this massive stagnation from 1985 to 1987? I’m sure it has almost everything to do with Don Estridge’s untimely death in 1985. I can’t imagine IBM releasing an XT years later with the same design language as the new ‘powerful’ machines, no doubt just fooling consumers into thinking they are ready for the 1990’s when instead, it’s a product more akin to 1982.

IBM PS/2 models at a glance – InfoWorld 6 Apr 1987

From Infoworld 1988:

On the one hand, IBM has shipped nearly 2 million PS/2s in the year since the machines were introduced. The Model 50 is currently the best-selling microcomputer in the industry a position it has held since November 1987, according to market research firm Store-board Inc. What makes these figures even more significant, say analysts, is that many of the alleged benefits of the PS/2 have yet to be fully exploited.
InfoWorld 4 Apr 1988

Although there was certainly an initial corporate interest in the PS/2’s IBM did not keep up with faster Intel CPUs quick enough and failed to keep up interest in the base models, leading to significant price cuts in the spring of 1988.

Drastic price cuts – InfoWorld 18 Apr 1988

Time and time again you’ll hear how there was no software poised to take charge of these 286/386 models, and there was no compelling reason to do so. And it’s why it was such a big mistake to not have allowed Microsoft to being GDI to OS/2 along with it’s working drivers & applications to have shortened development time to get them to market. By shipping these expensive premium machines without OS/2 (normal users don’t change operating systems), and the double slap insult being that none of these machines are capable out of the box of running *any* version of OS/2 it’s not hard to see why it failed.

Okay so the PS/2 was too expensive!

Actually, it was too cheap! They should have not bothered with the new look XTs it only created branding confusion, and really all 286/386 equipped models should have been able to run OS/2, with no upgrades needed. I can’t imagine anyone would be happy after spending six plus thousand on a new machine to only find out that to run the OS of the future, you need to spend a few more thousand.

Windows was irrelevant in 1987!

There is no doubt that being able to run Windows applications natively on OS/2 would have only helped it tremendously, as OS/2 would be the ‘professional’ version of Windows. Although OS/2 did achieve this through paravirtualization, having GDI/USER native to OS/2 would have consumed far less ram as you wouldn’t need to load two windowing environments at once!

While Balance of Power may not have been the #1 chart topper, it was one of the first commercial games for Windows (Maybe it was the first?), showing that instead of developing UI code & drivers, that even a run-time platform was a viable choice.

v86 mode was too difficult and it delayed OS/2 2.0 for years!

What if I told you that there is FOOTBALL & PIGSKIN? Granted they are text mode, but they absolutely incorporate v86 mode into what is basically OS/2 1.0. In 1987. Why was there no OS2/386? Yeah. IBM.

Instead, all the 1.x versions of OS/2 had a SINGLE MS-DOS box, or penalty box, even the 386 has the single DOS session limitation. So if your work flow was stuck to a single DOS session what compelling reason would there be to upgrade to OS/2? NONE. Speaking of 1987 however there was Windows/386 towards the end of the year.

Windows/386, is the friendliest glance into today’s future (Think of it as a graphical hypervisor, like VMware/KVM). Windows was the one environment where Microsoft didn’t need IBM’s permission to do anything, or adhere to any other standards, Microsoft added v86 support into Windows, and it brought mainframe power to the average user, by allowing them to create virtual machines running their own isolated MS-DOS applications, and even allowing copy/paste of data from between them, and into new Windows applications. While Windows 2 was a shadow of what would become the Windows 3.0 juggernaut of 1990, it was quickly headed in the right direction.

What is it with the 386 anyways?

And why were they so adverse to the 386? the 1st gen Model 80 motherboard feels more like a begrudging reaction to Compaq rather than what it should have been by the time they released the 3rd – 25Mhz version, with onboard cache controller & ram. Beyond v86 mode, there was the large memory space, and 32bit registers making it possible to port minicomputer (and even mainframe) programs to the PC. Was this desktop future too scary for IBM? Did they really thing that by refusing to adopt the 386 that they could somehow influence the rest of the market to not being 32bit computing to the masses? Even in the early 80’s there was the Definicon, a NS32016 cpu board you could plug into your IBM PC and unleash a programmable 32bit processor with upwards of 2MB of RAM. If IBM was not going to make a 32bit computer, others would find a way, utilizing the ever-increasing supply of open PC hardware.

As far as I can tell IBM didn’t even permit Windows/386 or any version of Windows to be bundled or shipped with the PS/2’s further alienating them from the growing market of software. And of course, by not increasing the RAM the pre-loaded operating system was still PC-DOS, not OS/2. It really shakes confidence when IBM won’t even preload their jointly developed Operating System of the future.

Then along came Windows.

While Windows 3.0 was fine enough running in 16bit protected mode on both the 286 & 386, having the ability to launch v86 machines, and take advantage of hardware paging of the 386 on Windows 3.0. At least you were 2/3rds of the chip’s capabilities, unlike OS/2 1.x where you used none.

There is money in those developer hills!

Time and time again, this has been one of the industry’s biggest failings. Just as IBM charged a fortune for SDK’s and DDKs all it did was raise the bar so high very few people paid for them, strangling the supply of apps & drivers.

While the PS/2’s were very expandable, it seems outside of collectors, very few are. Which again speaks to why it was so important to get that initial pre-loaded configuration right. And you control that with the pre-load, just as Apple forced the wedge by first loading OS X onto machines, then making it the default. At best with Warp IBM pre-loaded it on many devices, but users were oblivious that it was even there. It was more than once I’d seen someone buy a retail copy of Warp, to run this OS/2 thing to only find out their ThinkPad already had a copy.

The prices to get started with technical information, the toolkit and a compiler may seem expensive, but compared to the infamous $3,000 SDK & seminars.

As Steve would say – “Developers” – ViciousAloisius

Instead, developers should have been given copies for free, or even back then, on the MSPL. While the Microsoft Programmer’s Library is an invaluable resource, the lack of tools is just odd. Why even have slack space on those early CD-ROMs?

No doubt all the painful lessons were learned from OS/2 for Windows. Just as Windows NT ended up being everything NTOS/2 3.0 was going to be.

So yeah, really it was the PS/2 Model 60?

Bringing out a super expensive 16bit machine in 1987, holding Microsoft back in every technical way possible, along with all the poor choices revolving around IBM’s fear of the 386, and the 32bit future doomed OS/2 before it even began.

At best the 8086/80286 machines should have been cheap machines for MS-DOS present, but again the outlier is the PS/2 Model 60. Far too expensive with no real compelling reason to buy one – Don’t get me wrong I love mine! But it’s incredibly impractical.

If anything, once more again, OS/2 1.x should never been a thing, it performs terribly on 286’sand the single 3xdos session is just painful. With its heavy requirements, it always should have been targeting the 386, and the brave future of 1987 onwards, not 1984, and certainly not the PS/2 model 60, which never should have existed.

Hamstringing OS/2 to the $6,995 PS/2 model 60 in 1987 doomed it all from the start. It never stood a chance.

Phar Lap’s 286/DOS-Extender: why nobody used it for games

Posted on January 29, 2024 by neozeed

Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should.
-Ian Malcolm

Ever since I got my first 286 board way back in the early 90’s (1990? 1991?) I have been intrigued by the whole protected mode of operation. Unfortunately, in the era the required tools were way out of my reach, and of course were not available at retail. But now I live in the future where I have all the parts! Let’s look at the needed parts

I have to once more again thank my patrons, and people tolerating the google ads as it made all the difference in being able to buy all this stuff. And now is as good a time as any other to put it all together.

I stumbled upon this repo on sourceforge, Sarien. It included a Turbo C++ port, which is pretty exciting! So, this became my goal, get Sarien running on Phar Lap 286.

Installing Microsoft C requires you to pick and choose both hosting, targeting environments, along with what the preferred libraries are. In the business we call this foreshadowing as this can be such a giant PITA. At least virtual machines are fast, plentiful, and cheap. In addition I had been using MS-DOS player to host the tools on Windows 11. This of course proved weird later.

The first step was getting it running on MS-DOS using Microsoft C 6.0a. This was actually pretty easy, the hard part was working out the makefile, as some files don’t compile with optimisations. And overall, the project doesn’t seem to work with /Ox at all. I haven’t spent enough time mixing and matching settings to find what actually doesn’t work, but I’m in a hurry, and /Os seems to work just fine.

In no time I had both the CGA & VGA drivers up and running and verified working on my PS/2. Great!

Now comes the fun, getting it ready to run on Pharlap.

Phar Lap’s 286|DOS-Extender is pure magic. A DOS extender is a special program that can load a protected mode program into memory on a 286 or better computer and run it. At it’s heart, it can proxy MS-DOS functionality from protected mode to real mode, allowing you to use a lot of methodology and code from traditional real mode code. Phar Lap, goes beyond that by providing a pseudo OS/2 1.2 environment on MS-DOS, including advanced features like DLL’s, and being able to use ALL the RAM in your computer. Of course on the 286 there is a massive caveat:

The 286 has no built-in function for switching from protected mode to real mode. This makes programs that rely a LOT on MS-DOS potentially very slow. You can absolutely feel the difference between the real mode and the protected mode version of Sarien.

Phar Lap does include a test program, swtest which can benchmark the switching methods, so let’s run it and get some scores.

Switch code version = 1.14
BIOS signature: BA66CC86
BIOS date: 02/13/87

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 3 (SLOW) ... Test complete.
Avg switch time (usecs): To prot = 34, To real = 101, Total = 135
Min switch time (usecs): To prot = 32, To real = 98, Total = 130
Max switch time (usecs): To prot = 35, To real = 103, Total = 138

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 2 (AT) ... Test complete.
Avg switch time (usecs): To prot = 34, To real = 86, Total = 120
Min switch time (usecs): To prot = 33, To real = 83, Total = 116
Max switch time (usecs): To prot = 36, To real = 88, Total = 124

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 1 (SURE) ... Test complete.
Avg switch time (usecs): To prot = 34, To real = 70, Total = 104
Min switch time (usecs): To prot = 32, To real = 68, Total = 100
Max switch time (usecs): To prot = 35, To real = 72, Total = 107

For those of you wondering what the timing is like on a 386, here is my 16Mhz PS/2 Model 80 board (now with fully 32bit memory)

Switch code version = 1.14
BIOS signature: 039D2DB4
BIOS date: 03/30/87

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 5 (386) ... Test complete.
Avg switch time (usecs): To prot = 31, To real = 22, Total = 53
Min switch time (usecs): To prot = 30, To real = 20, Total = 50
Max switch time (usecs): To prot = 32, To real = 23, Total = 55

I’m honestly surprised the 286 switches from protected back to real so quickly! Although as you can see from the 386 timings it’s significantly faster than the 286.

Here is a quick video, real mode on the left, protected mode on the right. Yes I need to get a VGA capture card. Sorry.

Real mode on the left, Protected on the right. Running on the 386

Being a DOS extender it does have built in functions for things like hooking interrupts like this:

    /* install our new timer tick routine */
    DosSetPassToProtVec(IRQ0, (PIHANDLER)new_prot_timer_tick,
        &old_prot_timer_tick, &old_real_timer_tick);

Unlike some kind of OS/2 method which would involve creating a thread and or timers.

Setting video modes via the video BIOS is also supported, using the built in int86 style calls:

    memset(&r,0x0,sizeof(r));
    r.h.ah = 0;
    r.h.al = 3;
    int86(0x10, &r, &r);

Using pointers into things like video ram do require ‘asking for permission’ but it’s not too involved:

    int rseg;
  /* Get PM pointer to text screen */
    DosMapRealSeg(0xb800,4000,&rseg);
    textptr=MAKEP(rseg,0);

with the segment mapped, and a pointer to the segment, and now I can read/write directly into video RAM!

  /* save text screen */
    memcpy(textbuf,textptr,4000);

Just like that!

I’m not sure what I screwed up on the VGA graphics, as it doesn’t work correctly, but oddly enough CGA does work.

And now this is where everything goes off the rails.

It ran fine on emulation. So all excited I fired up the PS/2 and….

This lead me to more fun in how on earth to debug this. Of course Phar Lap 286 version 2.5 requires me to have Microsoft C/C++ 7.0. I shamelessly downloaded a disk set from pcjs.org. You actually need to install it, to copy out the files required:

28/05/1991 05:37 pm 47,216 CFIG286.EXE
26/11/1991 11:19 am 13,531 GORUN286.EXE
19/03/1992 04:00 am 42,720 shw0.dll
19/03/1992 04:00 am 105,039 eew0cxx.dll
19/03/1992 04:00 am 410,112 cvw4.exe
19/03/1992 04:00 am 91,118 eew0can.dll
19/03/1992 04:00 am 74,400 emw0w0.dll
03/08/1992 09:34 pm 2,649 INT33.DLL
03/08/1992 09:40 pm 2,718 MSG.DLL
03/08/1992 09:40 pm 1,702 NAMPIPES.DLL
03/08/1992 09:42 pm 2,073 NLS.DLL
03/08/1992 09:43 pm 5,184 PTRACE.DLL
03/08/1992 09:45 pm 2,320 SESMGR.DLL
03/08/1992 09:50 pm 1,508 WIN87EM.DLL
05/08/1992 12:04 am 3,100 KEYBOARD.DLL
05/08/1992 06:33 pm 270 TOOLHELP.DLL
14/08/1992 07:38 pm 7,891 KERNEL.DLL
14/08/1992 09:40 pm 14,545 USER.DLL
09/09/1992 10:59 pm 209,922 RUN286.EXE
09/09/1992 10:59 pm 229,046 RUN286D.EXE
14/09/1992 11:01 pm 14,024 TLW0LOC.DLL
17/09/1992 07:26 pm 34,152 CVP7.EXE

While CVP7 does come with Phar Lap, you have to run it via run286. As you may have noticed there is a mixture of OS/2 and Windows DLL’s in here, as at this point CodeView was a Windows protected mode debugger. The divorce was in full swing, and Microsoft C/C++ 7.0 had amputated the majority of OS/2 support. I’m sure all this is in the manuals, however all I have is disk images. There was no C 6.0a supported hosted debugger. Maybe it’s in the v1/v2 of Phar Lap 286, but I only have 2.5. There is version 3 files on the internet but I wanted to stick to 2.5.

And this is all I got. Yes, I did recompile with ‘/Od /Zi’ along with using cvpack on the executable. Yes, after copying the source to the PS/2 I was able to see the source line mapping, but it immediately jumps to assembly and GP Faults. All this is fine, but IT RUNS UNDER EMULATION.

What is going on?!

I asked around on discord, and found someone willing to test on their 286. It also crashed. I tried VMware and .. it crashed too! So did 86box! Ok now we’re going somewhere!

Since I had been using MS-DOS player to run the tools, I had an issue with the linker in C 6.0a crashing, so I tried the one from C/C++ 7. It also didn’t work. I tried the one from Visual C++ 1.5. It also failed. Almost giving up on the entire thing, since I had copied the source code to the PS/2, I tried something really silly, I compiled it using the /qc or QuickC flag. I wasn’t too worried about sizes as again I’m going to run in protected mode. It took some 20-30 minutes to compile, as 10Mhz machines are not the best for building software in this modern age. Much to my surprise it actually ran.

This was kind of shocking as I’m not sure what I screwed up to not get this to work, but it worked! I went ahead and changed the build to not use QuickC, but rebuild with /Os (Optimize for space). It took about an hour. And it too worked.

Phar Lap 286 running on OS/2 2.00 on VMware

Shockingly it runs! I’m not sure what on earth is up with the linking. I did find it easier to just rebuild on Qemu since it can easily map into my source directory and copy everything over and re-build very quickly.

Later I did try copying over compiled objects built using the MS-DOS Player, and linked them natively, and they ran fine.

What is it with the LINK?!

One weird thing on 86box is my pre-built machine I was using has a 5 1/4″ 1.2Mb floppy for the A: drive. It’s too small to fit MS-DOS, the game data and Phar Lap 286 all on there. Although Stacker to the rescue and it fits!

I removed a lot of Unix quality of life, to make it more MS-DOS dumping everything in the same directory so you can save & load games.

Assuming anyone is interested in this at all, I have the source up on github. I’ll follow up with some performance videos showing how much slower real vs protected mode is, along with some binaries/demos. A 5 1/4″ floppy disk image can be downloaded here for any suitable emulator.

Too many hard disks? The smiley face boot crash

Posted on January 22, 2024 by neozeed

I’d never seen this one before, but attempting to boot up PC-DOS 4.00 or 4.01 on my PS/2 model 60, with 7 virtual disks attached, all I get is a single smiley/happy face, ASCII 1 ‘☺’ on boot.

MS-DOS 5.00 doesn’t care.

all my SCSI virtual disks — too many disks!

While trying the Apricot MS-DOS 4 set I got on eBay, it boots from floppy disks, crashes trying to boot from the hard disk, and trying to run fdisk just causes a divide by zero error.

run-time error R6003
- integer divide by 0 — – integer divide by 0

run-time error R6003
- integer divide by 0

I’m a bit reluctant to rip the whole machine apart as SD card extension cables don’t work for me which is even more annoying. Didn’t people buy big machines and put in a LOT of disks to just run MS-DOS? Even a Netware server still requires MS-DOS to boot.

Is my 286 just too weird?!

I’m not sure if it’s worth following up, but it is perplexing. Maybe I need to rename all my disks, and stick with whatever was actually selling in 1987. And sadly that means not fully loading it out.

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

Posted on November 12, 2023 by neozeed

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?)

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.

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?

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

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

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.

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

Posted on October 27, 2023 by neozeed

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:

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”.

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!!!!….?

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.

Wow.

Just Wow.

LANDMARK 6.00

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.

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:

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.

More PS/2 upgrades! More RAM, More advanced SCSI!

Posted on September 29, 2023 by neozeed

So I had gotten this Boca Ram/2 card with 2MB of RAM, with space for an additional 6MB. Unfortunately trying to find matching memory has been a lost cause. Since the existing memory is 9 chip modules, I take that to mean it’s parity RAM, so I went shopping for much more available 3 chip modules.

I picked up 2x 1MB modules for £10.

Slotting them carefully into the ram card, taking great care as the clips are plastic!

Now from what I can remember being told is to never ever ever mix memory types like this. But logically I have to think that 9×1 = 4+4+1, right? RIGHT?!

I copied the @7A7A.ADF onto the reference disk image, slotted the card and booted up to the config, and toggled the card to 4M

I didn’t trust the auto-config, plus I just wanted to see what was there. Also I’ve always wondered if the PS/2 model 60 (or 30? 50z?) can slot higher density than the 256kb SIMM’s that IBM had used. I guess one day I’ll give it a shot.

Anyways thinking that this is about done, I save the config and reboot and now It’s Bocaram/2 issues.

Immediately, on reboot I get error 164.

164 POST detected a base memory or extended memory size mismatch error.

1. Run F1 Setup. Check System Summary menu for memory size change.
2. Run the Extended Memory Diagnostic tests.
IBM

Great.

Booting from the reference disk just crashes the PC.

Fantastic.

Pressing F1 however does let you boot, ignoring the issue.

After a bunch of digging I found this zip file with some utils. And just guessing br2pmems ‘fixes’ the CMOS settings allowing the machine to boot normally.

So now it’ll recognize the 5MB of RAM, and just boot normally. GREAT. But booting the reference disk still hangs the machine.

Which then brings me to the next upgrade:

The IBM SCSI with Cache aka the SPOCK. Since I ruined the one SCSI card, and ended up picking up a second card, but this time with the appropriate cable I’ve caused a massive market panic on Microchannel SCSI cards. Seriously check eBay, and you will see that the pricing has collapsed with many now selling in the £20-30 range. You’re welcome!

Not really wanting a 3rd SCSI card, but my eye saw this one with the cache RAM, and I figured if I wanted the ultimate PS/2 of course I’d want a caching controller. This looks to be the first rev of the PCB, but with the ‘hot fixes’ in place from the second rev. While the ROMs are stepping back to 1990, I don’t care much about the 1GB disk limit, as the BlueSCSI can emulate all the available devices in the chain, so I’m not losing anything in the way of capacity. This is a 286 after all.

Since the RAM card screws up the setup program, I have to remove it, and the old SCSI controller, re-configure the system with all the RAM and disks removed first. Then put in the new controller, and re-run setup.

I just accept the defaults, and reboot to check what happened. So far it looks good, slot 8 being near the middle of the PCB, and closer to the disk cage where the blue SCSI rests.

Remembering that the IBM controllers inventory the disks backwards, the 380MB disk image on SCSI ID 6, is the primary boot disk. I didn’t set it to the full 1GB as I want to later see how older versions of DOS/OS2 work with this, and I know they have issues with disks bigger than 512MB, but I figured matching a disk that did exist in 1988 would be more realistic.

With the SCSI setup, I could put the troublesome Boca board back with the RAM, and get my system booting up with the new “faster” SCSI controller, and all that new RAM.

Of course I did a few benchmarks on the old SCSI controller so I would know how much more awesome the new one is.

As you can see this is booted with my normal config.sys with a himem.sys and smartdrv from Windows 3.1 on a MS-DOS 5.1 install.

2,345.8 KB/sec With himem.sys & smartdrv
2,347.5 KB/sec with no himem.sys
2,316.6 KB/sec with runtime xmsmmgr & smartdrv
2,334.0 KB/sec with Windows 3.1 himem.sys no smartdrv

So, with these scores in hand, you can see that the penalty for various XMS memory access being turned on is there, but it’s nowhere near as massive as I’d have thought for performance. Even with it just being there, although again it’s so minimal.

Now for the real shocker:

That’s right, the advanced card is slower. A good 11% slower. Well, that was disappointing. I’m still keeping it in the machine, as having a hardware caching controller was all the rage, just like Mach microkernels. Maybe it’d make more of a difference in a 32bit system, but it’s performance is very underwhelming. For anyone wondering, the WDC AC2340, is an EIDE 340MB hard disk, with a 64kb cache. Im sure it was considered very fancy, and fast for the era, and it’s nice to know that no matter the SCSI controller, the BlueSCSI blows it out of the water. Also keeping in mind that MFM data transfers are usually sub 400KB/sec, so this is much more faster.

Okay you have all this XMS what are you going to do with it?

Well, after I did manage to get this original copy of Word for Windows 1.0, I thought that it would be a good test. One fun thing is that it includes the ‘runtime’ version of Windows 2.11, which can also upgrade an existing install of Windows 2 if detected. Running Windows 2 on MS-DOS 5, does involve loading the setver command in the config.sys, and rebooting. Windows 2 cannot use XMS (more on that) but instead uses the older LIM EMS standard that allows a 64kb page to be viewed from a far larger card. Since the 8086/80286 still use 64kb segments it’s not all that crazy to use.

And that brings me to this great program EMM286!

It allocates a 64kb page in low ROM, and backfills it from XMS. So I give it 3MB, and now I have 1.3MB of XMS left, and 3MB of LIM EMS ready for Windows!

So now I have EMS & XMS! And didn’t have to get some pesky EMS board either. I am pretty sure you need device drivers to use EMS, so how do you use LIM EMS under OS/2 1.x? I have no idea. Probably not I guess?

Anyways I run word, everything is great, it sees extra ram. I exit windows, and unload EMM286, and ..

3.4MB of XMS available? Somehow I lost a megabyte of RAM from Windows 2?! I’m not sure what is going on, or why or how Windows even touched it. Needless to say if you want it back, you need to reboot.

That’s right 494KB free! I thought MS-DOS under OS/2 just used some stubs in real mode, and called back to protected mode. No doubt this is totally wrong, there has to be some weird version of DOS+OS2 that actually runs in real mode going on here. I know that ‘bimodal drivers’ were a thing, but it sure seems like there really is a ‘real mode OS/2’ kernel with MS-DOS tacked onto the side.

Windows 3.0 standard mode, 286 + 5MB of RAM

It’s annoying OS/2 can’t tell you how much ram it sees and what is in use, but at least Windows 3.0 can. It’s more than enough to run Sim City, clearly making this one of the more expensive machines to run the game as intended. With the added RAM it doesn’t thrash as hard, but having emulated disks probably doesn’t matter as much as access time is always zero, and it’ll stream data as fast as it can. You can feel the difference moving between tasks, but things like the OS/2 file manager that loads a view into every directory is still incredibly slow. What were they thinking?!

Thouhts?

Back in the day this would have been an incredibly expensive upgrade. And is it worth it? The machine is still locked at 10Mhz. The FPU is also locked at 10Mhz, and you can feel it. The lightening fast disk access, despite it being some 11% slower is really hard to tell. Does the caching help at all? Applications don’t have to page in/out like crazy before as there is enough RAM to actually run them, but that is where the 10Mhz processor just isn’t there.

Just like the caching SCSI controller, I’m sure we’ve all heard how having that magical EMS memory would help out games like Wing Commander.

XMS/DOS High + EMM286 on the left, and just XMS + DOS High on the right

Well, I had to put them side by side, as I couldn’t believe it, but adding EMS made it noticeably slower. I was *NOT* expecting that. I should add that I used Vegas & this quick tutorial, on how to pan & resize one video to get them side by side. No doubt it’s not perfect but it’s enough to see that once the ship explodes, the performance on the EMS configuration is greatly throttled. It’s moments like this that makes me wonder is this something the caching SCSI card would do better implicitly? Or is it snake oil as well?

3MB is enough to load OS/2, and one application, just as Word v1 or Excel v2/v3 load just fine, but swapping between them is basically unloading one from memory, and loading the other back out to disk. It’s a shame RAM cost so much 1987-1992 as people really could have benefited from it. It’s just utterly bizarre that on such an outrageously expensive system that you even need RAM upgrade cards, it really should have been baked into the main logic board.

Installing the IBM SCSI / A ‘tribble’ card in an IBM PS/2 model 60, using BlueSCSI, and a tale of painful lessons.

Posted on September 17, 2023 by neozeed

As a follow up to Installing a Gotek floppy emulator, this time I’m adding something desperately needed, mass storage using a SCSI card.

The machine is the 40Mb MFM based model, the cheapest option of getting a PS/2 model 60 back in the day. MFM hard disks are incredibly old, and sadly the eventual end point for these old disks is death. While I had investigated a MFM disk emulator they are very costly, with prices starting at $299 USD. Ouch. However, from my Dec Alpha experiments I do have the BlueSCSI was available for a more reasonable £52. So all I would need was a SCSI adapter, and I’d be good to go, right? Mostly.

Looking at the card, you can see that it doesn’t use a standard 50 pin connector. I guess it being the 1980s and IBM trying to re-capture the PC market by going all in with proprietary connectors, they used a 50 pin IDC connector to attach the 50pin SCSI ribbon cable. This would prove to be disastrous for me later on. I initially had no luck finding an original cable, while the SCSI cards themselves seem to be plentiful on eBay. I guess me buying 2 of them has triggered a lot of movement in the market. Another source of concern is that the 286 is 16bit, and the card is advertised as being 32bit, but rest assured the notched middle part seems to indicate that the card is 32bit/16bit compatible. I can attest it works in my PS/2 just fine.

I had decided that since I do have a bunch of jumper cables, I could just solder them directly to the card fingers. I only have one device, so I don’t really need a ribbon cable, the BlueSCSI can emulate multiple devices, so I figured it’d be fine. Of the 50 pins in a SCSI ribbon more than half are ground, so I figured I only needed to solder up about 25 connections, just like how Apple got away with 25 pin connections. I did tone out the pins looking for the +5v power signal, along with checking the common ground, where the flip side of the SCSI card is all ground.

I had connected it up, and the machine saw the blue SCSI, but for some reason it was always reading 25Mb.

I was unable to figure out what was going on, so when I went to inspect my setup, I had seen one of the cables had disconnected. Uh-Oh.

As I pulled the card out of the computer, 3 more cables had popped off, revealing that the fingers were nowhere near as strong as I had thought, and the fingers had been torn off the card. Very sad. The card still ‘works’ but it’d need someone with a good eye and soldering skills to re-attach the pads, or just solder bodge wires from the test points on the card to the IDC connector.

Obviously if I’d known the fingers were so fragile, I’d have not done this. But I was impatient for the IDC connector to arrive (it took about a month), and I really thought I could get away with it. So I don’t know if it matters for anyone else, but yeah it turns out these fingers are nowhere near as strong to side to side forcers as I had thought. Also I was told “on the internet, so you know it’s true”‘ that various super glues are conductive, so test before you think about trying to do it live.

**IBM SCSI Adapter FRU 15F6561 IBM MICROCHANNEL SCSI 32 bit MCA Card + Cable**

And that is when this pair showed up, another SCSI card, but this time with the illusive cable. There is something weird how the universe times things.

So got this card & cable set (If it was available 3 weeks ago, obviously I would have ordered this one as it has the ribbon!).

Not knowing much about the IBM PS/2 SCSI/A adapter, I went ahead in BlueSCSI, and setup a 380MB disk on SCSI ID 0, a 1GB disk on ID1, and a 2GB disk on ID2. That’s when I found out that the adapter initialises the bus backwards.

I had thought it was a weird thing in the setup utility, so I booted up MS-DOS and ran FDISK to reveal that it really does read the ID’s backwards.

Obviously with the BlueSCSI they are just files on a SD card, so it’s trivial to just rename them.

I had also thought it was weird that the reference disk reads the disks being 2GB just fine, so I double up with both data disks being 2GB.

And sure enough, MS-DOS only sees 1GB per bigger disk. After search for a bit, it turns out that the 1GB limitation is a known thing and newer ROMs can work around the issue. Eagle eye’d might have noticed the first adapter had ROMs from 1990, while the second card has ROMs from 1991. But the better ROMs come from a totally different card. Normally I might have been annoyed, but since my disks are virtual I can just give myself 5x1GB data disks, along with that 360MB OS disk.

This is the best part of virtual peripherals, is that you can load out what would have been super expensive, and impractical for being era correct. Instead, now it’s super easy, barely an inconvenience. I can’t imagine trying to use physical disks in 2023.

One of the reasons I kept the smaller ‘C’ drive was to make for installing OSs a bit easier, as many older things hate ‘large’ disks. But being able to connect so many gives so much flexibility.

It’s a shame the MFM hard disk emulators are a bit expensive, even with my screwup it was still cheaper to go with SCSI, and the BlueSCSI basically just works, the only weird behaviour is all on the ‘tribble’ SCSI / A adapter.

Installing a Gotek floppy emulator in an IBM PS/2 model 60

Posted on September 5, 2023 by neozeed

Well like everything else, once you know what to do, its pretty self explanatory and easy. But until that point it’s a lot of trail and error.

The PS/2 model of computers went away from the PC/XT/AT design for something that would be more toolless and allow for more automation in the building & assembling of these machines. That means they removed loose wiring where possible to give not only great airflow, but an overall clean aesthetic to the PS/2 build. What this also means is that the old 34pin floppy ribbon will not do.

The PS/2 version uses and edge connection and integrates the 5v/12v power rails into the interface. You can try to add an old floppy to the mix, but there is 5 pins that need to be held high through a resistor pack to get an old floppy drive working. I didn’t want to fight it that much so instead I ordered an adapter from eBay, being sold by markgm.

Yes I don’t know what is up with the shipping either.

After much trial and error I found

After a lot of trial and error I found jumpering it for S0 was what worked. While I had read that JC was also needed, it just didn’t work when I tried. S0 puts the gotek into the first floppy position, in the older PC/XT/AT’s they jumper every drive as S1, but have a twist in the cable to negate it on the primary position.

The other catch is that it absolutely required a FF.cfg file

interface = ibmpc-hdout
host=pc-dos

Even though so many other systems didn’t need it, mine sure did. And Obviously I flashed my drive to the latest version of flashfloppy (3.41 as of now.). That also meant checking the processor type, which, is simple enough to check by opening it up, and setting your camera to maximum zoom.

Or checking the gallery of microcontrollers in the various Gotek’s. The prices have shot up dramatically over the last few years for unknown reasons, so they switched to from the ST to the AT line or similar processors.

Can’t say I blame them.

So with the drive updated, and config file loaded, along with a disk image, it finally booted up!

And with that in place I was able to boot the reference disk, and setup the system. The inside is a bit ugly but, I wanted to get this thing fully loaded, so I picked up an 80287-10.

One interesting thing about the PS/2 line of machines is that the 286’s could run their math coprocessors in synch. The IBM-5170/AT ran it asynchronously at 2/3rds the clock value. I would have imagined they convinced someone somewhere how at big step up from a 6Mhz 80286 & 4mhz 80287 to get into a PS/2 model 50/60 with a blistering 10Mhz 80286/287.

Happily the 80287-10 I had gotten from fractal2015, worked just fine.

Wow. awesome.

I’m waiting still for some cables to hook up the bluepill to the SCSI card, and the memory card, so I can run meaningful applications like SimCity for Windows, and OS/2.

PS/2 60 playing battletech, from a gotek emulated floppy

In the meantime I can do simple stuff from floppy. I’m still trying to keep an eye out for either an ethernet card, or a Token Ring card & MAU, along with cisco cards to at least let me use NetBEUI.

But for anyone else needing a solid answer on how to get the Gotek working with an IBM PS/2 model 60, here you go!

Virtually Fun

Fun with Virtualization

Category Archives: PS/2