This is pretty cool. A PC with an 80186 CPU is a little weird, though; I don't think many of those actually existed. It seems like virtually everybody went straight from 8086 to 80286
The Tandy 2000 used an 80186; I still have mine in the attic. It ran MSDOS 2.11, but it was not BIOS-compatible with the IBM PC (which explains why it was a market failure, even though it was technically superior in many ways). For example, you could mod it to have 896KB of base RAM (compared to the usual 640KB) - I had this done to mine. You could do this because video memory was mapped to a different location than with IBM PC's (but consequently, programs that wrote directly to video memory for speed wouldn't run unaltered on the 2000). I got tired of dealing with the incompatibilities and got a 286 from CompuAdd a couple of years later.
The Tandy 2000 was one. It was a PC-ish, DOS-running machine that was more powerful than anything put out by IBM at the time, but not PC compatible. The 186 had additional on-chip hardware like timers, etc. that the 8086 (and 286 and subsequent chips) did not, and some of these were mapped to I/O address space that corresponded to different PC hardware, so building a fully PC compatible machine with a 186 was near impossible.
Forgoing PC compatibility was not without its advantages. The Tandy 2000 could have up to 768k of RAM -- and used all of it, the 640k limit being nonexistent. This made a huge difference in applications such as Lotus 1-2-3. The Tandy 2000 also featured a 640x400 color display option -- extremely high resolution for the time -- at an affordable price, making it attractive as a graphical workstation. Tandy 2000s were used in the design of Stars and Stripes 87, an America's Cup winning yacht, and were also used to prototype color display in Windows 1.0. So it was an important machine, despite fading into obscurity due to its lack of PC compatibility.
Sorry, I just frickin' love this machine and wish it were more remembered.
Actually, you could go up to 896KB - it was not officially supported by Tandy, but there was a guy in Washington who had a company called Envision Designs that did this.
I think I read about him first in Jerry Pournelle's coolumn in BYTE. So he modded my 2000 up to 896KB, and also added a disk controller and hard drive. Tandy eventually started selling cards with an 8087, which definitely helped with floating point stuff.
It was a wonderful machine. I first ran Turbo Pascal on it, did my first color Mandelbrot set. I had the color monitor and the inkjet printer. What is incredible is that for what I spent in 1984 dollars on all that stuff, adjusted for inflation, I could probably now get dual Xeons with 20 cores!
It was a very sad day when I realized that it was getting too hard to deal with the incompatibility with the IBM-PC standard. The video RAM (and 640 x 400 8-color graphics), the nonstandard floppy disks, the add-on cards (which could be installed without opening the case), ... Technical superiority isn't always conclusive.
The original BYTE review, for anyone who's interested:
Yeah, those tray-like expansion cards were neat. Too bad that idea never caught on, and there were only a few expansion cards (all by Tandy) available for the machine.
PC compatibility basically steamrolled over all that. Maybe it was seeing what happened with the 2000 that convinced me from an early age that PCs were going to conquer the world, and Macintosh and Amiga fanboys were next on the chopping block. I couldn't even guess then how right I'd be; not even game consoles avoided turning into cut-down, purpose-built PCs.
At the time, I was just disappointed that the only graphical game that actually worked with the 2000 was a specially ported Flight Simulator 1.0.
The latch-things that were supposed to secure the cards in the slots apparently didn't seat the cards tightly enough. My dealer finally just replaced them with screws after I complained a few times about the graphics card coming loose, resulting in a poor signal.
Compatibility has been great in some ways. But with standards in flux back then, there was more variety (and maybe fun) than there is now. Besides experiments like the 2000, there were things like machines with 2 different CPUs (the Commodore SuperPet had a 6502 and a 6809, and I think the DEC Rainbow had a Z80 and and 8088). There were so many 5.25" floppy formats you needed utilities like Xenocopy to convert among them (I think it fiddled with the drive controller to manipulate the drive heads).
With machines being simpler, you could fiddle a lot more. Many magazines published assembly language code for little games and utilities; for that matter, the computer section of a typical bookstore carried lots of books on assembly language. There were books on microcomputer system design, stuff about how things worked at the chip level. All gone.
I remember Flight Simulator. I couldn't believe it the first time I played it. Crashed the plane over and over ... There was a graphical paint program, and other graphical stuff which worked with the very slow mouse - in fact, I have a copy of an ad featuring Bill Gates in which he describes using the 2000 in designing the early versions of Windows.
I'm a bit surprised that in your list of dual-CPU systems you didn't mention Tandy's own Model 16 -- which was a TRS-80 Model II fitted with a 68000 daughtercard and up to 768KiB RAM for the secondary processor. It was the first Unix-capable desktop not to come out of Sun.
UK people might remember it as it was pretty popular in schools in the late 80s/early 90s
The Nimbus was an absolute horrific trainwreck of a machine - RM were only able to supplant the far superior Acorn in schools due to backdoor shenanigans. Imagine the world now if kids who had grown up on Archimedes went into companies and started using that tech there, we would be 15-20 years ahead of where we are now technologically. Instead the geniuses at the department of education collectively shot us all in the face.
Prior to their purchase, I recall my dad spending some time trying to persuade my headmistress that the RM Nimbus was a bad choice and we should have "real PCs" in school instead. Unfortunately it turned out the powers that be had a contract with RM and the choice of machine was basically forced upon schools.
With that said, beyond the odd software incompatibilities, I found it an interesting system. Its BASIC was pretty good and it had a music chip integrated at a time when almost no machines had sound cards.
There wasn't any real reason to use the 80186 in a PC; it was meant for embedded devices. The only major feature that it had was some additional hardware for timers and DMA built in. Everything else was (more or less) architecturally the same as the 8086.
Probably the last series of 80186 PCs ever made were HP's 100LX / 200LX, a palmtop DOS based PDA that was released in the mid-'90s IIRC. It was an amazing little gadget for its time.
Those were compatible but actually used the NEC V20 processor. I have a 95LX, 100LX, a couple 200LX and I'm in the market for a 4MB 200LX and maybe the 1000CX (which lacks the built-in spreadsheet).
My other major hardware hobby project is a custom clone of a 100LX, based on a PIC32 running RetroBSD! Wire-wrapping tiny membrane keys is damned painful however so it’s been on the back burner for a while
Actually, I'm partly mistaken. The 95LX had the V20. The 100LX, 200LX, and 1000CX it seems had an Intel 80c186 codenamed "Hornet" which competed with the V20.
The ICON was a computer built specifically for use in schools, to fill a standard created by the Ontario Ministry of Education. It was based on the Intel 80186 CPU and ran an early version of QNX, a Unix-like operating system.
I cut my teeth on a "Siemens PC-D", a German variation on the IBM PC. Not quite compatible but almost.
It had an 80186, 1MB of RAM (extreme at the time) and many other niceties that a normal IBM PC didn't have. I think it even had an external MMU, at least it could run SINIX. Though there were UNIX clones like PC/IX and early XENIX versions that ran without MMU on stock IBM XTs, without protection obviously, so I'm not certain what the story with SINIX on the PC-D was.
Certainly was an Apricot, and the does look like it and may well be it, but this was 1984/5, which predates the 300 release. That said, was working for government IT department in one of the regional electricity supply companies and do recall the kit was in for evaluation and we did get pre-release kit in to look at. Though we are talking 8086 CPU time-rame here.
But without a doubt though it was an apricot, thank you for that. I did have a quick look or older models it may of been, nothing could pindown for sure. Though pre-release eval kit back then was much more fun and creative than today's verbatim to release.
The 80186 would have been a natural successor to the 8086 in personal computers. However, because its integrated hardware was incompatible with the hardware used in the original IBM PC, the 80286 was used as the successor instead in the IBM PC/AT.
In other words, the few "PCs" which did use a 186 weren't fully PC-compatible.
It was possible: "Being IBM PC/XT compatible and running MS-DOS 5.0 from ROM, the HP 200LX can run virtually any program that would run on a full-size PC compatible computer as long as the code is written for the Intel 8086, 8088 or 80186 CPU and can run using CGA graphics. It can also run programs written for the 80286 CPU, provided they do not require the use of protected mode.":
It is not that you cannot build 186-based PC-compatible computer, but on the other hand using 186 for PC is somewhat pointless because you cannot use most of things that 186 adds to 86/88 in order to remain PC compatible.
> A PC with an 80186 CPU is a little weird, though; I don't think many of those actually existed. It seems like virtually everybody went straight from 8086 to 80286
In the late 1980s, the network server on my high school computer classroom’s LAN was a ’186; the actual PCs were either 8086 or 8088 machines.
The 80186 was an 8086 integrated with some of the peripheral chips mainly used in embedded devices. You can still get some SBCs with 8018 compatible chips.
For some time 80186 was quite common in SCSI devices. I've seen large amounts of 5.25" (and larger) SCSI harddrives with 80186 and IIRC some RS/6000 workstations had 80186 in their SCSI controller (on MCA card).
It is one of the saner Intel's attempts at x86-compatible embedded CPU with integrated peripherals.
