Tag Archives: workstation

Vintage Fan replacement

Making some noise

Working with vintage computers has many aspects and one of them, nearly throughout every component, is noise.
Hard-drives whirr, floppy-disks rattle, the CRT emits a high-pitch whistle and on top of it all at least one fan is blowing like a jet-engine. Time for a fan replacement!

Luckily since these days, much quieter fans have been developed during the last 30 years – so let’s just swap the fan and… ahhh, silence. I did that with my Sun Blade 150 and it worked great!

…well, it’s actually not that simple all the time.

Blown by the wind

System cooling was handled a bit different back in the 80’s and 90’s. Practically there were just 3 levels of cooling:

  • None – convection had to do the job.
  • One for all – one fan cooled the whole system
  • Insane – Either huuuuuge Fans (>8″) or some mad-scientist liquid-cooling was used. I won’t touch these in this post…

The “no fan” class were all so-called home-computers and the lower-end models of the early 16-bit machines like the ATARI ST, Commodore Amiga 500 or the first Apple Macintoshes (Steve Jobs was fanatic about convection cooling).

The most prominent “single fan” family members were office PCs up to the 486-class as well as any desktop/deskside 68k Apple Macintosh. All these had one fan sitting in their power-supply, blowing the warm air out to the back of the case.
Please mind the warm air. We’re not talking hot streams of  death-rays here. While CPUs weren’t a big heat-source issue (until the advent of the i486/50) passive heatsinks were sufficient to cool them by the air-flow/draft through the case created by the PSU.
For such Personal Computer systems it can be perfectly fine to replace some old, noisy fans with recent high-tech whirls. Especially if the PSU was also replaced by something more modern (like I did with my Quadra 950) producing less heat than the original one.

This is a totally different story when it comes down to workstations.
An en-vogue (UNIX) workstation back in the days was mostly designed using a relatively small pizza-box sized case, nicely snuggling underneath a monstrous 21″ CRT. To name just a few there were

  • SUN SparcStation 1 to 20
  • SGI Indy
  • Digital VAX/DECstation
  • Many HP PA-RISC 7xx

These boxes were cramped (hard-drives, expansion cards, lots of RAM) and their high-end processors ran much hotter than those x86 and 68k in personal computers.
Surprisingly none of them had a dedicated CPU fan mounted – instead they all relied on the power of the fan installed in the PSU.

Under pressure

Searching the web, you will find many texts recommending to put a quieter PC into your workstation. Vintage-me says: Don’t!

In case of workstations (pun intended!) a new indicator is needed in the game of fan replacement.
While the ‘PC world’ just looks at the CFM value (cubic feet per minute, i.e. airflow) as a performance indicator, workstation owners need to check the static pressure delivered by a fan. This is measured in mm/H20 (millimeter of water) and means how strong is a fan pulling air over obstacles and/or through venting slits etc. – think vacuum cleaner.
In consequence, two fans having about the same CFM value might be completely different when it comes down to static pressure. This is a nice table I found on the web comparing some high-performance fans with standard PC ones and the Papst 8412N is a good example of what I just wrote: The much liked NF-A8  has just 25% less CFM but only half the mm/H20:

Fan Airflow [CFM] Static pressure [mmH2O] RPM Noise [dB]
Panaflo FBA08A12U1A 46.9 4.8 3450 38.2
EBM Papst 8412N 40.6 4 3100 32.0
Noctua NF-A8 FLX 30 1.96 2000 16.1
Noctua NF-R8 31 1.4 1800 17.1
Arctic F8 31 1 2000 20

That power naturally comes at a price: More revs and much more noise… which is inevitable at the given mm/H20 power.

What’s cooking?

So what happens if I chose the wrong fan?
If a low-pressure fan is placed in an airflow path with lots of obstacles, the fan’s airflow will reduce and it will cool only the nearby components, but won’t have enough juice to suck heat from parts further away.
This means it will only cool (parts of) the power supply and the rest of the workstation will be more-or-less cooled by convection and the internal temperature will accumulate. Running such a machine for a longer duration will lead to ‘effects’. From errors to crashes, even smoke and finally destruction.

C’mon, that’s folklore, Axel!” – Not a bit my friend.
I just had this experience when I thought that my MIPS RS2030 workstation could do just fine with a somewhat more silent, recent fan. The original one is/was a Delta AFB0812HH – a hellish loud fan. But even a  Noctua NF-A8 with a mm/H2O of nearly 2 made the small MIPS workstation unstable. First the PSU housing got really warm in the middle (switching regulators are screwed onto it there) and after 30 minutes of torture (compiling code) I got more and more SCSI I/O errors until the system completely froze.
Changing the fan back to the noisy one everything ran rock-solid. Quod erat demonstrandum!

So what should I do?

There’s no general advise to follow. If you want to keep your original PSU it might be possible to use a more silent fan for just the PSU and add one or more fans caring for the case ventilation.
Your milage may vary and multiple modern fans -which also need to be mounted somehow- might add up producing the same amount of noise like the single original did.

The cleanest solution is replacing the original PSU innards by more modern & smaller parts which then draw less power and therefore dissipate less heat, requiring less cooling.
This is especially advisable if you have the feeling that the original PSU gives fist signs of ageing (smell, heat, buzzing). Better safe than sorry!

MIPS RS2030 – the resurrection

As mentioned in the first MIPS RS2030 post, I’ve got mine off ePay around 2004 and after some testing its life was about slowly moving through my basement waiting for it resurrection…


The long way into the light

So, in 2004 the RS2030 wasn’t in the best condition: No front bezel, no hard-drive and a flakey DALLAS clock-chip. There were 8MB of SIPP modules plugged in and luckily it came with the original keyboard, a monitor cable and two QIC tapes from 1989 containing RISCos 4.10.
I fiddled around with it for a bit, still having a 21″ CRT on my desk, happily connecting to the BNC cable and the tapes were still readable but I wasn’t able to get things booting without a tiny bit of documentation. At least I added 8 more 1MB SIPPs for small money to fill it to the brim.

This changed 2012, when I got in contact with Julien Noël, who ran no-l.org (wayback-machine link) which pretty well described how to install RISCos. Well, he had a MIPS Magnum 4000 and used a bootp() server, but it described a lot of things I was desperately needing for my resurrection.
Some mails flew back and forth, a BNC-to-VGA adapter was build and little RS2030 saw some daylight again. Sadly my QIC tape-drive disintegrated over the last years and its pressure rollers turned into sticky goo – and I figured this out, when the goo slowly crawled into my precious tapes. Yikes!  😥
I cleaned the tapes as good as possible and everything went back into the darkness of “Zee Vault™” again. I think it was the next month, when Julian sent me a tarball containing RISCos 4.52 tape images. I saved them in a safe place and moved on…

Now or never!

This year (2018) I had more time at hand than usual and plenty of it went into some of my Macs and a comparably vintage SGI Personal IRIS.
During my fight practicing with installing IRIX 5.3 onto a clean drive I felt like prepared for an even older MIPS box. This time it had to be done! I got myself a new-old-stock QIC drive, 2 still sealed QIC-150 tapes and moved everything in front of my LG TFT display, which is able to handle sync-on-green signals.
Let’s check if it’s still alive at all – flick the switch, a noisy fan starts blowing and ~45sec and some beeps later the RS2030 is back in business:

Yes, the console looks strange. It just uses 2/3 of the screen and has a frame around it. The green tint is due to my way too long video cable.

Ok, there are many “FAILED” messages but it found all RAM and the ROM monitor (aka BIOS) prompt is happily blinking. Woohoo! I left it running/idling like this for a while just to make sure the power-supply stays stable.
After half an hour I moved on. The fails of the NVRAM and Counter/Timer test showed that the DALLAS DS1287 clock-chip finally went flat. The failed SCSI Master Test gave me a bigger shiver…

The clock-chip was quickly removed, the ram content saved, cut-open and enhanced with an external 3V button cell. It’s a common drill for all vintage hardware enthusiasts. I think this is the mother of all clock-chip modding posts.
Luckily the SCSI Master Test went away with the modded DS1287. Phew… while I had my beloved EPROM programmer at hand, I also saved the four 27c512 EPROMs and some Googling actually brought up a  more recent version than mine: v4.30 from Jul. 1989 vs. 4.32 from Jan.1991. You can download the binary images here. The most useful difference I found is the added ‘sprobe‘ command, listing all SCSI devices found.

There’s a nice thing all computers should (still) have. A 7-segment display next to the EPROMs giving you some idea of the systems status while booting. Also pictured the modded clockchip.

I found an older post of somebody desperately looking for a keyboard. While it looks like an XT-keyboard and weights like an IBM model M, it seems to be somewhat special. As said, I’m lucky to gave gotten mine together with the RC2030.

This was the last step: Check the drives. Find a proper SCSI hard-drive and externally connect my new tape-drive.
Having learned from my “tape disaster” in 2012 I carefully checked my tapes before putting them into my precious new tape-drive. And yes, they had a problem: The the slack retention belt was worn out and lost its elasticity…. resulting in, well, slack. To fix this you need a new(er) tape as ‘belt-donor’ and then do some tape-DJ’ing.

As I wasn’t able to find 2 reliable donor tapes, I decided to not dump the RISCos 4.10 tapes and move on…


It’s getting serious: I took my two best blank QIC tapes and copied the RISCos 4.52 tape-images onto them using Linux on my retro-server (which one day deserves a post for itself). That was the easy part…

Let the game begin

Using Juliens recipe the initial boot from the tapes went smooth. Well, at least for 90’s measurement. Times were different, so it’s definitely not slap in some DVD/USB-stick and let the BIOS do the rest – choose some packages to be installed and baaam!, OS installed.
This is the drill (theoretically):

  • Use the minimal boot command of the ROM Monitor to boot a stand-alone shell (‘sash‘) from the 3rd block of the tape.
  • This sash knows filesystems, so you can use it to temporarily copy a mini-root system from tape block #4 into the swap-partition
  • Then load the RISCos kernel from tape telling him where to find the mini-root filesystem.
  • Finally this kernel loads a full-blown shell which then is able to execute the install script (‘inst’).

But if you’re not owning an original hard-drive you have to format/partition yours first. In this case you have to “boot” the MIPS format tool. It’s the grandfather of SGI IRIX’ fx, just even more basic.
basic. And confusing. Out of the box, it “knows” 13 hard-drive models, of which 8 aren’t even SCSI. And all of them are very, very, very obsolete. Here’s the printout:

Option #13 gave me some hope… “other” means you can add your own drive – if you have these specs at hand:

Well, I guess you don’t. Neither did I. So I wasted spent 2 days to figure out how to get a partition scheme and whatever else is needed by RISCos onto my disk.
To spare you this experience, bad ideas are:

  • Use the IRIX’ fx tool
  • Use gParted
  • experiment with those wiredo specs

The solution is -as most of the time- simple. Choose some SCSI disk from the menu, answer all questions but deny formatting, so it will write all partitions and the so-called volume header (a partition containing sash and stuff). The tool ‘prtvtoc’ (PRinT Volume Table Of Content) will then show you something like this:

After that you can boot sash, miniroot und finally start ‘inst’. Again a very simple installation tool which creates the EFS filesystem and copies all packages onto the hard-drive. Time for a break… tapes are slow and it’ll take ~2hrs.

So tonight I’m gonna party like it’s nineteen ninety-nine

When that’s done, you have to reboot and your MIPS will boot like a proper workstation… back in the days. It takes some minutes and it greets you with a simple ‘sh’ prompt.

To make your life a bit easier quickly enter ‘chsh’ to switch into ‘csh’ which is a bit more modern.
From there have fun exploring your new, old system. Ah, and don’t forget: RISCos is not year 2000 aware. So set the clock to something before December 1999 😉

Don’t miss the next chapter: Home improvement… making things a bit more convenient.

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 😉

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

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.