Tag Archives: unix

The MIPS RS2030

Intro: The sleeping beauty

Well, the MIPS RS2030 isn’t really a beauty – but it slept quite a while in my basement. Actually, it’s a mediocre UNIX workstation at best… but there are many things about it, making it a special piece of my collection – and as an returning reader of GeekDot you may know I have a soft spot for those whacky things from back then… and as often with my posts, this one will be the most detailed you’ll be able to find. The RS2030 is yet another lonely system.
Well, if you look like this, you’re not the hottest thing in the Workstation-Discotheque ūüėČ

First things first

MIPS… Even if you have just a dim knowledge about processor history, this name will ring a bell… Founded in 1982 MIPS created the first commercially available RISC CPU and until 1992, they were system manufacturers, too.
The RS2030 had many “firsts”: It was one of their first models, featuring their first CPU, the R2000, and somewhat paved their way into the market while immediately hurting MIPS’ reputation… more about that later. And last but not least,¬†the used OS was one of the first 32-bit operating systems (1985) for RISC-based workstation-class computers.

So here are the specs:

  • Insane 12 (VAX)MIPS squeezed out of an 16.6MHz R2000 CPU and R2010 FPU. 32KB external Cache should speed things up a bit…
  • Up to 16MB (yes, that’s the max) RAM
  • 10Mbps ethernet… that’s 10base2 or an AUI transceiver.
  • 4MB/s synchronous SCSI interface (internal space for one 3.5″ HD)
  • Two RS232 ports controlled by an NEC V50.
  • Optional monochrome or color frame-buffer
  • Optional 3.5″ floppy drive

Just for the record: There was a 2nd model called RC2030, which only differed by not having the frame-buffer. It was sold as server… that’s why the put the “C” in the name. Errr, no, it’s… not… logical. So I’ll forget about this and move on.

The official brochure pictured all these parts like this:

Nice, but missing the power-supply and stuff… in reality, my RS2030 looks like this from the top:

Yeah, I’m missing the the hard-drive carrier – but the same goes for the front bezel, so what the heck… OTOH I have the mighty color frame-buffer, which you can see to the right of the huge power-supply in the middle. It is capable of 1280x1024x8bits/pixel at 60Hz. Here it is in more detail:

Here’s my mainboard having the PSU and frame-buffer removed, revealing the glorious R2000 and his math-bro’ R2010 as well as the V50 “I/O processor” and 4 mysterious MIPS custom chips :

Right behind where the frame-buffer sat, above the CPU/FPU you’ll find the L2 caches and RAM slots. These are SIPP modules and the maximum supported are 16x1MB.
Back in 1989 that was many… not much, but enough for a serious workstation:

Looking closely you’ll notice the cut cables for the 2nd fan (wasn’t me!). A small but very loud one meant to cool the RAM and most important the CPU/FPU underneath the frame-buffer.
Because I currently run the RS2030 without lid, it’s OK. But after some hours it gets quite hot in that region.

To the left of the power-supply (which has another very loud fan) are supposed two carriers for the hard-drive and the floppy-drive. Both were absent when I got this little beast.
Underneath the drives are the ethernet and SCSI controllers as well as the 4 EPROMs containing the “BIOS”, aka monitor.
Like all workstations back then, the RS2030 boots into a monitor, a basic software which gives you some means of setup and options to boot from HD, tape or network. More about this in the next chapter about setting things up.

To round things up, here’s the back side – connectors are from left-to-right:
Keyboard (DIN), 10base2 & AUI ethernet, SCSI, one parallel, two serial connectors and on top the frame-buffer. Mind the uncommon “0W3” RGB connector.

The OS with the many names

Finally, the RS2030 -like all MIPS workstations- ran a strange flavour of UNIX called UMIPS or MIPS OS or¬†RISC/os or RISCos (not to be confused with Acorn Ltd.’s RiscOS)… all tree names/notations are used randomly across documents and mails from those times. So Googling stuff is a drag, 99% of the hits are Acorns RiscOS pages.
It seems MIPS’ operating system started out as UMIPS (UnixMIPS) and settled to RISCos around 1990.
As said, in 1992 MIPS gave up making computers… and was sold to Silicon Graphics (SGI). And playing around with early IRIX versions you smell RISCos all over the place – it’s definitely the mother (or father) of IRIX.

Anyhow, like other Unices of those times, RISCos is hard to get used to it as it misses all those comfortable things we got used to in these Linux days. No bash, no editor but vi etc… To make things short, here’s the Wikipedia roundup:
RISC/os was based largely on UNIX System V with additions from 4.3BSD UNIX, ported to the MIPS architecture. It was a “dual-universe” operating system, meaning that it had separate, switchable runtime environments providing compatibility with either System V Release 3 or 4.3BSD.

Rant, rant, rant…

As said in the beginning, the RS2030 wasn’t quite the showpiece for MIPS. During my research I came across many disgruntled posts about this and other MIPS machine(s).
It actually seems that the RS2030 wasn’t even designed by MIPS but taken over from some other company (my assumption is ‘Integrated Solutions Inc.’¬†given the marking on the frame-buffer) to fill a gap. Here’s the gist featuring replies by someone who obviously worked for MIPS back then:

>>Between the sloppy I/O implementation (the RS2030 was designed by a
>>now-defunct-or-nearly-so workstation company, whose design Mips had to finish
>>to allow the delivery on a large contract; the bozos who did the box used an
>>off-the-shelf NEC V50 chip for I/O and programmed it poorly, causing lame
>>serial and SCSI performance where simply using the R2000 would have worked
>>better), the lack of expandability and the proprietary memory modules…

The options at the time were:
a) Walk away from a deal for a few thousand systems, a large percentage¬†at the time of Mips’ total base
b) Manufacture only the few thousand systems, and make little or no money on each because of economy-of-scale issues
c) Build and announce the 2030, and keep going on the next generation (albeit somewhat delayed)

(a) and (b) would have resulted in no Mips workstation product at all
that year, which would have been dramatically worse for the company.
The strategic direction at the time was to expect most serial i/o to
come in from terminal servers (this was subsequently modified somewhat).
In addition, issues of SCSI performance did not become apparent and reproduceable from quite some time after product launch.

>Surely MIPS could at least provide new ROMs for the V50? Or did the
>bozos solder them in?
There are some reliability fixes available. As for performance, let’s
face it: nobody’s going to spend money to improve the performance of a
system, at no return, years after it has been dropped from the product
line.

Wow, so it was deliver something mediocre and move-on quickly to create something better. IMHO not the best way to build a good reputation.
This probably led to comments like this:

Unfortunately, computers made by MIPS Co. were ill-engineered products. They were error-prone. From my limited experiences, they easily got broken. We had many broken RC2030s (early times RISC desktop with sloooooow R2000, codenamed “Jupiter”) and many broken RC3230s.
We stock them unwillingly and dumped eventually with disappointments.

Does this make me turning away from this poor little, mediocre thing. Not a bit! It’s an important piece of IT history – and because this is GeekDot, I will make it work for its money.

So follow me to the next chapter: RC2030 – The resurrection.

Siemens PC-X

This is an oddball from the very early days of the PC/XT world. And as you might have seen yourself browsing this page, I have a soft spot for the oddballs… ok, now for the facts:

The Siemens PC-X is based on the original “PC-D” design. Actually besides the ROM, the MMU, a slightly different graphics card and a hard drive¬†as standard they’re the same… BUT the “X” came with SINIX, ¬†Siemens’ XENIX based flavor of UNIX. That’s somewhat impressive when you check out the rather limited specs:

  • 8MHz i80186 CPU
  • 1MB RAM
  • 10-20MB hard drive (depending on drive used)
  • ¬†640x350x1 bit Black on white display – that was very high-rez back then

Yes, the PC-X/D were one of the few machines using the 80186 instead of the “industry standard” 8088/8086.
That move seemed to be advanced but it was a step backwards actually, because all those machines were more or less incompatible to the available, ever-growing MS-DOS software library.
For the “X” model, it was even worse. Running SINIX you more or less totally depended on Siemens for getting Software. There was their own office suite and you could buy MS Word/Multiplan/Chart and dBase II from them. Well, pretty ok to run a¬†multitasking( !) office system ¬†in 1984. Here’s a video showing a PC-X booting into SINIX:


Because nearly everything was non-standard in this beast (graphics, expansion bus etc), its career didn’t take long. I love the keyboard, though. It looks very 80’s and is another example of German over-engineering: You can run over it with your car, it’ll still works – like an IBM Type M.

This is what you see as soon you opened the 0.8mm thick steel case – left 3rd the huge power-supply, front drive case, back the mezzanine bus:

PCX_1stlook

Remove the drive-cage (Left:¬†BASF 6188 10MB MFM hard drive and right: TEAC FD-55FV floppy) and you’ll see¬†the GPIB/RS232 expansion card – very simple NEC D7210 design – the external connector is marked “DF√ú” (German acronym for “Datenfern√ľbertragung”, i.e. Modem and stuff) :

PCX_Serial

Next in the “stack” is the graphics card which also controls the keyboard. It seems to be different from the one used in the PC-D version. Left side a 8031 and a SCB2673 (Video attributes controller), 2 EPROMs (D39/40) and a 2k SRAM.
Right side, a SCN2672 (Programmable Video Timing Controller) with its own 8K EPROM (D12) and 4k of SRAM:

PCX_GraKa

Having removed that expansion board you have the full view of the main board – Bottom right the RAM, left the CPU, a WD2791 Floppy controller and of course the 80186 CPU and MMU:

PCX_Mainboard

If you also remove the power supply, you will find another odd thing (also a bit visible at the left edge of the above picture): A¬†SCSI-to-MFM converter board, the “DTC 520B“. So SIEMENS¬†decided it’s better to fit an MFM hard disk and this converter than using the on-board SCSI bus an provide an (expensive) SCSI drive. Mhhh…

PCX_SCSI2MFM

The reason to finally write this post is that I was asked for an image of SINIX and of the PC-X’s ROM to get the whole thing emulated in MESS.
So here are the ROM images of what I have. Maybe I’ll be able to add some more floppy images… stay tuned.

Other versions

While browsing the web, I came about another version of the mainboard and graphics-card. According to their model numbers and their design, they seem to be predecessors of my boards.

Here’s the mainboard. While mine has model W26361-D270-Z6-05-36, this one is marked -D270-Z6-02-05.
Many ICs are featuring a ceramic case. The RAM seems to be put on a separate PCB

PCX_AltMainbo_W26361

The graphics-card has more differences (mine is¬†W26361-D310-Z4-03-5, this one is -D282-Z4-10-5. The ICs are placed differently, its design looks more cluttered and some ICs aren’t populated¬†on the board at all.

PCX_AltGraKa_D282

Tips

If you got your SINIX running -maybe a¬†previously¬†installed version- and you cannot get root access here’s a hack to get root access ¬†(assuming you can login as guest w/o password (commonly named ‘gast’). ¬†It¬†bases on a mistakenly¬†set permission:

/usr/lib is writable for everybody

$ ls -ld /usr/lib 
drwxrwxrwx root /usr/lib

in there is a crontab file. Copy that to /tmp, delete the original and copy your version back to /usr/lib to make it yours:

$ cp /usr/lib/crontab /tmp
$ rm /usr/lib/crontab
$ cp /tmp/crontab /usr/lib

Now you can edit ‘your crontab’ with an¬†editor (ced)¬†and add one line like this:

* * * * * /bin/chown gast /etc/passwd

So after one minute /etc/passwd is yours, too.
Now you can remove roots (or admins) password by changing

root:cHuykydasds: (or something like that)

to

root::

Voil√°, this SINIX is yours ūüėČ

Another thing you might need is to move data in/out. The only initial way to do this is a tool called ‘trados‘. This can read/write 360KB (only!) DOS floppies. At least a start…

Next steps

Finally, when revisiting this machine after quite some years in my basement, there are some tempting things to check out:

  • Can I replace the DTC 520B and use a SCSI drive directly?
  • As the SRAMs on the graphics board are sitting in bigger sockets – what will happen if I use bigger SRAMs? This might be answered when the emulation is working and we can fiddle with the video firmware to use more SRAM.