Received the most weird 'PC'

Hi,

In this video I want to show you one of the weirdest PCs I've ever received.

I was lucky enough to receive this one from a viewer from Saudi Arabia and I'm really excited to give you this walkthrough and hopefully get it up and running

[tomatolicious]

I have a complete system of the same kind. Still with all the original boxes and documentation. You can make your own cable which will work with any generic monochrome BAS monitor.

It should also be noted that this is identical to the Siemens PC-D. With the PC-X being the unix version (SINIX) and the PC-D being the DOS version

[bjn]

12:53: That CPU is in fact not a PLCC package, but rather the "LCC" package variant. PLCC (Plastic Leaded Chip Carrier) chips have contact pads on the bottom and has exposed "leads, " while LCC (Leadless Chip Carrier) has the contacts on the bottom, because the IC still has no leads but rather the pads on the underside of the chip package, as you can see at 13:05, where these pads are visible on the CPU package running to the IC at the center. Also LCC sockets _require_ a retention mechanism, as opposed to PLCC sockets which are self-retaining.

[eformance]

80186 makes sense now, Siemens built industrial CNC controls in the 80's using that processor. Notably the Hardinge CHNC 1 series were equipped with the Siemens 810T control. This was an 80186 powered control with a VME bus and passive backplane design. The 80186 includes most of the glue ASICs that were needed on 8088 and 286 based machines, designed for embedded and industrial use. A couple PC companies built systems with the 186 processor, such as MAD Computer Inc.

[ChipGuy]

15:47: what you call "additional ROM chips" are not ROM chips at all. It is 2 times intel 8259 Interrupt controller and 3 times SCN2661 serial interface ICs. The total memory of that machine is 512KByte since it has 16 chips with 256K bit each. The entire memory bus architecture is 16 bit. This is why there are 2 BIOS ROMS and 16 DRAM chips.

[omegamsx]

Those orange capacitors in the PSU are known for failing short circuit, I'd check them out!

[bad.sector]

Interesting find! I have some additions...
The ISA connector has also been used in GDR Robotron EC 1834 machines - albeit with normally laid out cards, where this connector just replaced the ISA connector. Not only that, the EC 1834 also had 720k floppies in use!
The 186 is indeed rare (have one, but no board to run it). It doesn't have an edge with 1 MB memory, the 8088 can address the same. It DOES however include some new commands and some operations run a bit quicker. The new commands were later continued to be used with the 286 (e.g. pusha, popa for registers on the stack). The main reason this isn't mainstream though is that includes some circuitry that is normally found on the MoBo itself, like a clock gen, interrupt controller, etc. Therefore it was incompatible with many existing board designs.

[GodmanchesterGoblin]

The video controller card uses the SCN2674 - consequently the card is completely incompatible with regular PC video controllers which where based on the older MC6845. The SCN 2674 was a much more capable controller although not very widely used. Also interesting that the board has it's own microcontroller (NEC 8741) and an 8k byte ROM (perhaps OTPROM) presumably for font data. I love the use of the DIN 41612 connector for the main bus in this computer. They were very widely used in industrial computer systems in the 80s-90s.

[ErraticPT]

A 80186, a pretty rare beast indeed.
Mostly used in industrial systems, that would explain the strange keyboard that looks similar to a POS terminal/ruggedised industrial one.
One thing I'd check is the 4 pin power connectors, make sure they are wired the standard way, I've seen similar example systems that had the 12v running on the normal 5v pins and 5v on the 12v pins despite the connector being standard fit. Nice way to blow things up!

[cmjones]

Interesting to see 80186 in a PC. I've got a piece of laboratory equipment (Tektronix CSA803A oscilloscope) which uses several of them, and if memory serves they're in sockets like the one in the Siemens PC too.

[galier]

Not PC compatible. Can't be with a 80186. The 80186 integrates the DMA controller and the timer chip in package (chip select decoder etc.) which are not compatible with the 8 bit peripheral chips IBM chose for their PC. There were several PC that were built around the 80186, the Philips :YES, the Siemans PC-D, SMT-Goupil G4, several HP models and many more. All were not fully PC compatible even if they used MS-DOS as OS (PC-D had an adapted MS-DOS 2.11 version).
The 80186 was probably the least known Intel CPU with the longest production time if one counts the embedded derivatives. AMD presented new models up into the millenium. The 186/188 was an excellent embedded processor. We used it extensively in the company I worked for in Germany in th 90s.

[SiDWiNDR]

No need to undo the slot screws fully (around 7:00) - they're designed to loosen up then fit through the bigger hole ;-)

[dougjohnson]

Even if it won't run just having an 80186 for show is cool.

[darknessblades]

That white connector is a PCI/104 adapter, it is often used in Industrial machines, where space is limited, so stacking cards is the best solution.

[RoomerJ]

So someone sent you a box full of siemen...

[maxtornogood]

Good luck finding a monitor & keyboard for this particular PC, I suspect they aren't exactly common!

[SproutyPottedPlant]

It reminds me of the Acorn A5000. It too had expansion cards with those connectors, this is no Acorn though!

[nneeerrrd]

wrong, 80186 had the same memory model as 88/86. Improvements were in the speed of MUL/DIV/bitshift operations, plus some new useful instructions.

[chriswareham]

I believe these were used for SCADA systems (industrial process control), as an alternative to hardware from Digital Equipment Corporation. They wouldn't have been running DOS, but a form of Unix. Likewise, the DEC hardware often ran a form of Unix called Ultrix instead of VMS.

[TotoGuy-Original]

wow a 186 didnt know these existed i thought it was like movies where you dont call the first one 1 lol

[mattwright]

I wonder if this was used for some sort of automation controls.