Here's another random tidbit of 80186 exotica from a little less than a year ago:

https://hackaday.com/2017/11/03/386-too-much- … 186-in-an-fpga/

Scali wrote:

My thoughts here are that the 8086 and 80186 were rather 'unfortunate' products in the history of the PC.
That is, they were 16-bit CPUs in an era where the 'real' PC platform was still 8-bit. 16-bit ISA slots and chipsets were not introduced until the PC/AT with the 286 CPU. So I have never seen a 'full' 16-bit machine based on an 8086 or 80186. They were generally XT-class machines with a 16-bit CPU shoehorned in for some reason, but not taking full advantage.

Since there have been various homebrew projects to create 8088 machines, wouldn't it be interesting if such a project were extended to an 8086 or 80186 and create a proper 16-bit machine, to unlock the full power and features of these CPUs? Just to see 'what could have been'? 😀

I've come across a couple of examples of 8086-based PCs, and at least one of them had 16-bit (non-ISA) buses. This is the only one I can remember at the moment:

https://en.wikipedia.org/wiki/PC-9800_series

Of course it would be Japanese. I'd never heard of this thing when I was a kid, but I've run across mentions of it recently because of my love of vintage & retro gaming. (There are some cool anime games that were original to the PC-98 that made their way to the standard PC world.) The bus slots on the motherboards for it look like 8-bit PC slots because they're roughly the same length and have only one segment, but they have a different number of pins and are noted to be 16-bit.

Apparently it was really an IBM decision NOT to use the 8086 and NOT to use 16-bit slots, until, as you said, the AT debuted with the 286 CPU.

Strange, in my opinion. But maybe it made sense from an economic standpoint for IBM at that particular time. They did set the standard which has evolved into what we still use today, so it's hard to say they were wrong, exactly.

aquishix wrote:

Apparently it was really an IBM decision NOT to use the 8086 and NOT to use 16-bit slots, until, as you said, the AT debuted with the 286 CPU.

The story I heard was that both the 8088 and Motorola 68000 were in the race when IBM was designing the PC.
Ultimately they chose against the 68000 because it would require them to develop a more expensive 16-bit infrastructure, and possibly develop their own custom chips, because the 68000 ecosystem was still in its infancy (Apple decided to go with the 68000 in the Lisa at the same time, so we can see what happened there).
The 8088 was chosen because it was backward-compatible with the Intel 8085 peripheral chips. IBM already had experience building 8085 systems using cheap off-the-shelf parts (see the IBM Datamaster), and they could recycle a lot of that for the PC.
For this reason the 8086 was probably never even considered as an option (if you are going 16-bit anyway, picking the 68000 over the 8086 is a no-brainer).
Here's a nice story on that: https://archive.org/stream/byte-magazine-1990 … e/n451/mode/2up

aquishix wrote:

They did set the standard which has evolved into what we still use today, so it's hard to say they were wrong, exactly.

Depends on who you ask, I suppose.
Leads us back to the Betamax-VHS discussion. VHS won, but wasn't technically superior to Betamax. It was more about price, availability, convenience etc.
I think the same goes for the IBM PC. I personally think that IBM 'accidentally' made the PC a success, because it was so easy to clone. Ultimately it was the clones that made the PC platform a success, because IBM itself was always overpriced and underperforming.
It was all the clones that drove prices down and performance up, to the point where the line between business computer and home computer was completely blurred.

Scali wrote:

My thoughts here are that the 8086 and 80186 were rather 'unfortunate' products in the history of the PC.
That is, they were 16-bit CPUs in an era where the 'real' PC platform was still 8-bit. 16-bit ISA slots and chipsets were not introduced until the PC/AT with the 286 CPU. So I have never seen a 'full' 16-bit machine based on an 8086 or 80186. They were generally XT-class machines with a 16-bit CPU shoehorned in for some reason, but not taking full advantage.

http://www.vcfed.org/forum/showthread.php?282 … odesl-25-amp-30

Is this an example of the kind of system you were referring to?

aquishix wrote:

Is this an example of the kind of system you were referring to?

Yes, that's a quirky not-quite-XT, not-quite-AT model, with a lot of proprietary stuff, and won't accept regular 16-bit add-ons.

In Yugoslavia Novkabel launched in 1985 a ET188A PC-XT compatible machine based on a 80188 CPU.
Machine was fully compatible with PC-XT clones with MS-DOS or CP/M.
They chose 188 cpu because it had integrated peripherals so design of the motherboard was easier.
Technical Specifications:
CPU: Intel 80188 running at 8MHz
ROM: 8 KB custom made BIOS
RAM: 256KB (ET-188) or 512 KB (ET-188A), expandable up to 640 KB
Operating system: MS-DOS 3.20
Secondary storage: 2 x 5.25’’ 360KB floppy drive or 5.25’’ 360KB floppy drive + 22MB Tandon hard disk
Display: CGA compatible adapter (color text 40x25, 80x25 or graphic 320x200, 640x200) or Hercules compatible adapter (monochrome 80x25 text or graphic 720x348)
Sound: beeper
I/O ports: DE9 video output, RS-232, parallel port, keyboard

kokerich wrote:

In Yugoslavia Novkabel launched in 1985 a ET188A PC-XT compatible machine based on a 80188 CPU. Machine was fully compatible wit […]
Show full quote

In Yugoslavia Novkabel launched in 1985 a ET188A PC-XT compatible machine based on a 80188 CPU.
Machine was fully compatible with PC-XT clones with MS-DOS or CP/M.
They chose 188 cpu because it had integrated peripherals so design of the motherboard was easier.
Technical Specifications:
CPU: Intel 80188 running at 8MHz
ROM: 8 KB custom made BIOS
RAM: 256KB (ET-188) or 512 KB (ET-188A), expandable up to 640 KB
Operating system: MS-DOS 3.20
Secondary storage: 2 x 5.25’’ 360KB floppy drive or 5.25’’ 360KB floppy drive + 22MB Tandon hard disk
Display: CGA compatible adapter (color text 40x25, 80x25 or graphic 320x200, 640x200) or Hercules compatible adapter (monochrome 80x25 text or graphic 720x348)
Sound: beeper
I/O ports: DE9 video output, RS-232, parallel port, keyboard

Fantastic piece of history. Thank you!

Hello to you all , i'm also interested in creating the 80186 based system, i have the highest performing variants of this cpu , with the correcponding socket, plcc68 , i know it needs to be fed 2x the actual cpu clock speed , but not much more right now , i would spend time reading and designing the circuitry that will make use of this cpu, but i feel if i do it alone without any help it might take forever. Is there anyone who also wants to create such machine eventually?

i have the scanned Tandy 2000 Service manual , that might come handy at some point i guess, at least in the design part.

Do you want to make just a 186 based system or you want to make a IBM PC (or some other existing standard) compatible machine ?

Tiido wrote on 2023-11-26, 13:30:

Do you want to make just a 186 based system or you want to make a IBM PC (or some other existing standard) compatible machine ?

Exactly, and on this subject, I had access to the leftovers from beige box XT class system motherboards in college. Amongst these fully pc/XT clone compatible motherboards were 8086 and 80186 boards with 8 bit ISA and 16 bit banks of ram. Boards were all baby AT form factor . Guessing they all went to ewaste.

I believe most were mid to late 80’s
From what I was told none of the 186 chips onboard components were used.

But I’ve seen old timers grumble that certain late revision 80186 chips were made to be more pc/xt compatible (maybe Chuck)

So it’s possible you could reuse on chip components if you get a late rev 186, Chuck says so.

All the internal peripherals can be ignored, although BIOS will need to set them up so that way first (but aware software can mess with that stuff if it really wanted).

But as far as IBM PC goes, you need the timer, IRQ and DMA controller along with KBC that all work exactly the same way as original parts, same memory map and of course BIOS that provides all the same functions in same way. It is a significant amount of work to make a IBM PC compatible machine.

Oh man there's a ton of stoof I need to get back to in this thread. Hopefully by tomorrow.

BUT ... there was a Yugoslavian 80188 based PC??? WHY WASN'T I TOLD PRIOR. Someone is going to pay 🤣. I will need more details. Names, addresses.

Worldwide there were likely 3 dozen or more i0188/80186 based PCs. The moat significant 1 arguably was the Mindset.

I will get back to this thread. I have 3 Russian 8086s, 5 N80188s and now another 8086 staring at me (forget the make, Rockwell maybe). I want to build something 80188 based also.

Don't forget the Radio Electronics RE Robot brain, aka Vesta Technologies oem-188. They sent me at least so.eme.of the rom images years ago. I know someone who built the whole robot. But he may not be talking to me anymore 🙁

This topic deserves it's own forum. Or website. Maybe ...

For now I'll conclude with this. There was an 80188 project board, s100 based iirc. N8VEM
Apparently there was controversy, IP issues. I believe it was completed though. But it was just a dooky board imo. The Ampro board was much more interesting imo. I never had 1, but do habe the LittleBoard/PC (NEC v40 equipped).

aquishix wrote on 2018-09-21, 14:49:

I'm intensely interested in creating an Intel 80186 based system, but all of the motherboards I've seen for sale thus far appear […]
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I'm intensely interested in creating an Intel 80186 based system, but all of the motherboards I've seen for sale thus far appear to be intended for microcontroller applications. That's not surprising, since it seems like the 80186 was mostly used for controller cards/boards of various types. The only 80186 I've ever owned was the brain of an ISA SCSI controller that I acquired a few months ago.

But I'm interested in getting my hands on one for gaming. I would love to get compilers(or assemblers) that work on a 80186 or at least TARGET the 80186 architecture, so I could fix whatever incompatibilities are in the source code and re-compile(or re-assemble) them for the 80186.

Does anyone know what kind of video and sound hardware might be out there that's compatible with the 80186? What about drive interfaces?

I saw someone post a reference to this: https://en.wikipedia.org/wiki/Philips_:YES

But I haven't been able to find any of those (current or Sold) on eBay...so I'm inferring that they're exceedingly rare.

Any information on this insanely niche corner of the vintage computing/gaming space would be appreciated. The 80186 has fascinated me for a while now because it is the most obscure member of the x86 family as far as I can tell.

It may be that later versions of MASM for instance adopted support for specific 80186/88 instructions. But if you were just looking to modify code for 8086/88, that's a non issue. Anything would work. But ... if the target system is say a Tandy 2000, which had it's own very obscure graphics chpset, the task of adapting a game will be 100x harder then you think. If the game accesses hardware directly (very likely). There are other reasons for incompatibility. But those constitute the biggest part to my knowlwdge.

Graphics hardware isn't specific to cpus. A system with an 80186 will run a 6845 of whatever else you design for it. Most IBM incompatibles used the NEC upd7220 for graphics. The CGA/MDA/hercules used the 6845. Tandy 2k - SMC chips. The 6845 can be setup (initially by it's own firmware or the mobo bios) to run differently then say a cga card, yielding more colors, higher resolution. Some systems did this. And they were incompatible with the cga.

stamasd wrote on 2018-09-21, 16:16:

The 80186 wasn't used in PCs much because it was more expensive while not offering any advantages for a PC over a standard 8086. All of the extra peripherals integrated in it couldn't be used in a standard PC architecture because they were interfaced in a manner that was incompatible with PC hardware thus useless if you wanted to maintain compatibility (wrong base addresses etc)

The onboard peripherals could also be ignored (they didn't have to be utilized). The Tandy 2000 did this for the most part. The Tandy 2000 doesn't have the 8237 DMA controller. Not really a compatibility issue afaik. But who knows.

Jo22 wrote on 2018-09-22, 09:51:

That's right. Though IBM PC compatibilty wasn't all that important in the first half of the 1980s. Originally, system makers ass […]
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That's right. Though IBM PC compatibilty wasn't all that important in the first half of the 1980s.
Originally, system makers assumed that industry kept going the CP/M way of hardware independence,
so MS-DOS compatibility was considered good enough for a while. Unfortunately, things went different and programmers started to
do a lot of bare metal programming, assuming everyone had an IBM PC. This broke compatibility for a lot of early systems,
which were only DOS and partially PC-BIOS compatible. Anyway, I'm no PC/XT expert. Just summing up what I learned from reading old magazines.

🤣 lOL compatibility was extremely important in every part of the 80s (except 1980, non IBM puters were all the rage). Thing is if you bought a Tandy 2000 say, and had a few dozen titles to choose from, you maybe were fat (as was I), dumb (as I was definitely), and happy for a while. Until you tried to boot Starflight 🙁. A lot of hot titles were available. There's a sourceforge or github site full of Tandy 2000 specific s/w and docs if you google.

Merovign wrote on 2018-09-22, 10:24:

I believe the company was called "Computer Products United," the acronym was definitely C.P.U., and they were California-based a […]
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I believe the company was called "Computer Products United," the acronym was definitely C.P.U., and they were California-based and they had ads in the late 80s and early 90s in PC Magazine and maybe Byte - they had a 186-based PC for sale to the general public as a budget alternative.

I've never seen one personally and don't know anyone who has. 🙁

I just looked at 3 issues of PC Magazine from different years and only saw 8088 and 286 and 386 machines, but I remember seeing an ad and noting they had a 186 machine listed.

The Littleboard would be a real project, but doable with a lot of know-how and detailed manuals.

I called them in 1989. They wantwd 400$ for that motherboard. Was too rich for me.

Zup wrote on 2018-09-22, 11:10:

Well, I don't think so. […]
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Well, I don't think so.

8086 and Nec V30 were paired with 16 bits memory banks, so they got some speed improvements over their 8 bits (8088/V20) counterparts. Although there weren't many XTs with 16 bit slots, keep on mind that almost all peripherals on XT era were sloooow (keyboard, serial, parallel). HDD controller would have benefited, but HDDs from that era were so slow that it didn't matter. I'm not sure how much performance could be gained by using a CGA/Hercules/EGA 16 bit card... EGA was more common on AT systems. And the only examples I remember of VGA XTs (Amstrad 2086, Olivetti PCS86) have the video chip onboard (I wonder if it uses 8 or 16 bit bus).

80186 was a dead end for mainstream PCs. All peripherals were placed at odd addresses, so it only could (and sometimes could not) achieve compatibility at BIOS level. Many programas used direct port access to work faster, so they could not work properly on that systems. But it found a niche market on embedded systems, and some PC compatible PDAs (i.e.: my HP 200LX) were built around a 80186.

(Also, 80186 was used on network cards, SCSI controllers and in some printer boards so it was not a total failure)

Total loads were used as microcontrollers. It wasn't a failure at all, was just repurposed. The IBM Professional Graphics Controller used an 8088. I think there were 3 clones of that card(s). One was made by Vermont Microsystems, the only clone I have. It uses an 80188. There is another graphics card out there, which may be more of an early gen locker that uses an 80186. I forget the specifics.

Scali wrote on 2018-09-22, 11:26:

Well, I upgraded my 10 MHz 8088 with a Paradise VGA card. I had various friends who also had an 8088 or V20 with VGA. With a 16- […]
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Zup wrote:

And the only examples I remember of VGA XTs (Amstrad 2086, Olivetti PCS86) have the video chip onboard (I wonder if it uses 8 or 16 bit bus).

Well, I upgraded my 10 MHz 8088 with a Paradise VGA card. I had various friends who also had an 8088 or V20 with VGA.
With a 16-bit ISA bus, you could use a super-fast VGA card such as an ET4000, to completely remove the bottleneck to videomemory. I wonder just how fast a system can be with an 8086 or 186.
I have a 286-20 with ET4000 myself, and it's pretty amazing what you can make it do with well-optimized code.

Which couls lead someone to ask what would it take to get an AT mobo to run with an 80186 instead of tje 286. Huh - schmott, no?