Tag Archives: DIY


This is a hack which is very similar to the DesperRAM. It was born out of pure despair, so it’s neither elegant nor very clever – but it works and that’s what counts.

During the “BOZO resurrection“, I had one specific PAL under suspicion to not working correctly any more. That PAL was soldered (i.e. not socketed) onto the board in a very tight spot, so I wasn’t able to cut the pins as close as possible down on the board.
I know, there are special pliers which can somewhat around corners, but my trustworthy Knipex (The pliers maker in the world, full stop.) can’t. So I had to cut the pins right at the PALs package – easy and quick.

The downside is that this method leaves you with a leg-less IC… and if you then decide it might be useful to read-out that IC (like I did) it’s time to slap your forehead :-/
But not so fast, young Padawan. Despair has the advantage that it normally can’t get worse, so nothing to lose. Even you cut the legs off you still can spot the tiny remains leading into the package. So why not trying to replace the amputated legs with artificial limbs!?

My initial thought was soldering new pins to the package, but the remaining connection is way too small to allow anything to be soldered to it but a human hair.
So I used a socket, turned upside-down, slightly bent the legs inward, squeezed the PAL between the sockets legs and carefully soldered the pins to the case-connectors. Finally I put small bits of wire into the sockets empty holes to create new pins to connect the whole thing to my GAL-programmer. Voilá: FrankenPAL


Yes, it looks horrible and I was quite sure that this doesn’t work but it just costed me 10 minutes, so what the heck, let’s try read-out that beast.

What should I say? It worked right on the first try… So never despair as long as you have a working solder iron 😉

Paradico – “The cube”

This is yet another pretty unknown Transputer module. The silkscreen print says “PARADICO – beheer submodule – BOP 1990”. Well, beheer is Dutch for management, so it was the management submodule for… something.

I got myself 4 of those from my Transputer-Bro’ Mike and after a good year of lying in my cupboard it was overdue to do something with them.
Mike was kind enough to do the basic deciphering of all the traces, links and stuff, so it was basically just building & wireing a front- and back-plane to get them working.

This is how one PARADICO looks like:


Not everthing is readable here but it does the job because the PARADICO is a pretty standard Transputer design. More or less a huge TRAM. So nothing fancy about it:

  • One T800-25 Transputer
  • 4MB DRAM (4×256)
  • Some PALs for the memory decoding
  • Buffers for the links
  • A 5MHz oscillator
  • A fuse… just to be safe 😉
  • Handy jumpers for LinkSpeed and CPUSpeed

IMHO this is actually quite a waste of space but in these days you have to take what you get, right? 😉

Ok, so I ordered 8 DIN41612 sockets and after a day worth of soldering “The Cube” was finished:


“The Cube? It’s not square at all!” you might say. Yes, true, but the specs are all nicely squared so here’s the proof. The Cube has: 2² Transputers running at 5² Mhz, each has its own 2²MB RAM. Voilà, a cube 😉
For the convenience of connecting the cube to more or less any other system, I’ve added a hex-inverter so notAnalyse, notReset & notError can be converted into their “positive” counterparts (in the upper left corner of the picture, next to 3 red jumpers).

This is the ispy output connected to the “Gerlach Card“:

Using 150 ispy 3.23 | mtest 3.22
# Part rate Link# [  Link0  Link1  Link2  Link3 ] RAM,cycle
0 T800d-24 240k 0 [   HOST    1:0    …    … ] 4K,1 1024K,3;
1 T800d-25 1.8M 0 [    0:1    2:0    3:0    4:0 ] 4K,1 4096K,4;
2 T800d-25 1.8M 0 [    1:1    …    …    … ] 4K,1 4096K,4;
3 T800d-24 1.8M 0 [    1:2    …    …    … ] 4K,1 4096K,4;
4 T800d-24 1.8M 0 [    1:3    …    …    … ] 4K,1 4096K,4;

And if you happen to stumble over a Pradico yourself, here’s the pinout of the front  DIN41612 connectors:

          X  A32 C32   X
        GND  A31 C31  GND
 UpNotError  A30 C30  DownNotError
 UpNotAnaly  A29 C29  DownNotAnaly
 UpNotReset  A28 C28  DownNotError
        GND  A27 C27  GND
         X   A26 C26   X
   LinkOut0  A25 C25  LinkOut1
    LinkIn0  A24 C24  LinkIn1
        GND  A23 C23  GND
        GND  A22 C22  GND
         X   A21 C21   X
   LinkOut2  A20 C20  LinkOut3
    LinkIn2  A19 C19  LinkIn3
        GND  A18 C18  GND
         X   A17 C17   X
        GND  A16 C16  VCC
        GND  A15 C15  VCC
         X   A14 C14   X
         X   A13 C13   X
         X   A12 C12   X

1 LinkSpecial
2 Link0Special
3 Link123Special

1 ProcSpeedSel0
2 ProcSpeedSel1
3 ProcSpeedSel2

Next up: The Cube moves into the Tower of Power… when other more important things are done.

Fixing scratched traces

This is the price you have to pay if you’re into real men’s hardware:

Being (falsely) identified as “old crap”, some cool things end up in the dumpsters… or worse. Being tossed around in some storage for years, probably stacked with other cards and boards, it might happen that some traces on the outer layers got badly scratched, thus making the board/card non-working. Here’s how I try to fix scartched traces… and most of the times it works:

First make sure that the circuit path (trace) is really broken – I just may look like, but isn’t.
To do this you need a volt-meter. Follow the suspected trace in both directions until you find a pin or through-hole it is connected to. Use these two points to test if the trace is still connected.

Ok, damn, it’s broken 🙁 You need three things:

  1. A sharp knife or scalpel
  2. Adhesive tape (Scotch, Tesa or whatever it’s called in your corner of the world)
  3. Conductive (silver) lacquer

Conductive-what? Conductive lacquer is actually a cool thing to play with… but be prepared: It’s not cheap (about 9-10 Euros). It comes in tiny bottles or as a pen, which is even more expensive (20+ Euros). The bottles look like this (lacquer and diluter):


Ok, the process is quite simple:

  1. Use the knife to scratch-off some of the coating lacquer on both ends where the trace was “cut” until you see some copper shining through.
  2. Check with your volt-meter that you actually have contact with one end and e.g. a pin on the other end of the trace. Do this for both “halves” of the cut trace.
  3. Mask the place you’re going to ‘heal’ with your adhesive tape – this prevents the conductive lacquer to run all over your board.
  4. Apply the conductive silver lacquer onto the spot you’ve just masked and let it dry (read the manual that came with the lacquer – yeah it’s unmanly but nobody will see you ;-))
  5. Using your volt-meter, check again. This time from both ends of the complete trace.

If you’ve done everything right, the  trace should work again – and so does your card/board! Yay!

Here’s how my badly scatched MiroHIGHRISC looks like in certain places – can you spot the little silver dot?


Final hit: Some lacquers are quite thin on silver (blame the manufacturer) so after some days the spot you just fixed might become unreliable. In this case you might repeat the procedure to get more silver to that spot.

Removing pin rows

Removing pin rows…doh! It took me quite some time to figure out a working solution for this problem, so I thought it might be useful to you some day, too.

Some idio^h^h^h^h not so clever person cut off all the pins on one of my DSM860 RAM boards – I probably will never figure out why (may a lightning hit him!). Besides 8 of the pins all other 74 (!) where cut, rendering the ram card non-functional (it’s the memory bus connector).

Here’s a (blurry enlarged) picture of the mess:


I started to desolder some pins from the back-side of the card but soon found out that the solder was too old to be removed the classic way (desolder pump & wick). Also, that pin-row (41×2) was one piece, so I would have to completely remove all the solder before I would be able to pull the part from the card.

After some thinking I came to this solution, which worked quite good:

First you need to cut away the plastic part from the top of the board. I used a very fine and sharp  caliper to cut away one pin after the other (i.e. like a single jumper).
While doing so be careful not to cut into the board!
Then pull or push the plastic pieces from the pins, again one after the other – I used a thin knife pushed under the plastic an gently wiggling it over the pin.

When done, it should look like this:


You may spot that some pins are missing already – that’s because my previous desolder tries sometimes seemed to work. Still, I couldn’t avoid that some pins got bent. This is the time for my secret repair tools: Syringe needles!

Second, get two kind of needles:  Gauge 18 and 20, that is 0.9mm and 1.2mm, color code yellow and pink. Cut off the tip of the needles and use a rasp to make the edge straight and clean. They should look like this then:


The bigger needle (G20) is just perfect to be completely pushed over a pin which then can be bent into any position without the risk of breaking it off – it works like this:

(This is just a showcase picture with a different board, the needle needs to be pushed all the way down over the pin)

So straighten all the pins into an upright position. This will be important for the next step!

Now put your board into a vertical position (e.g. fixed by a bench vise or clamped between your inner thighs ;-)), get out your solder iron and the G18 needle – this needle should be just small enough to fit through a pin-hole.

This is the third and last step. Place the G18 needle over the pin you like to desolder on the back-side of the board like showed here:


From the other side you’re touching the base of the pin with your solder iron. As soon as the solder starts to melt gently push the needle onto the pin.
If everything works like it did for me, you will push the needle through the board, including the solder and the pin you’ve planned to remove!

The great thing with this is that the needle (being made of steel) does not stick to the solder. As soon as the needle got a bit colder, you can easily remove the pin as well as the excess solder from the needle with your fingers!
Now carefully pull back the needle through the board and you should have a nice and clean through-hole in the board. If not, a final cleaning with a desolder-pump or wick should do it.

This needle-trick also works brilliantly with empty pin-holes which got filled with solder. Just place the needle on the pin-hole on one side of the board, heat up the solder on the other side while pushing the needle. Pop! There goes the solder!

As said, this technique worked great for me. All 82 pins got removed, a new pin-row was soldered into place and the card is now working like a charm.

Still, do this at your own risk!
I’m not going to be taken liable for any damage to your board or your health!
If your unsure if you are able to perform this stunt, don’t do it!
Practice with an old scrap board/card before you fiddle with the “real thing”!


You might have been in the same situation: Some piece of old hardware could be upgraded (aka pimped) with more RAM, but there’s no place in the world to get that type of RAM needed.

In my case it was 1Mx4 DRAM in a DIL packaging. It’s hard to come by those in a ZIP packaging – sometimes used on AMIGA RAM cards – but DIL is next to impossible.

Well, when 1Mbit RAM chips were introduced, the industry switched to SIMMs anyway… and that’s where you find those. For the DespeRAM, SOJ packaging is what you want. SOJ (sometimes also called J-Lead) means there are short pins on the IC but they’re bend inwards under the chip… pretty much like PLCC pins.

What you need for this stunt:

  • Desperation. Lots of it.
  • A hot-gun (for getting the SOJ chips off the SIMM module)
  • A fine tip on your solder-iron. Very thin solder led (e.g. 0.5mm)
  • DIL sockets for your desired piece of crap^h^h^h^h vintage hardware
  • Wire, also thin (I used 0.6mm)


Clean desk. Good lighting. A steady hand (no coffee or drugs – I assure you, it won’t work. I tried it ;))

Ok, so first of all get out the hot-gun and carefully get the ICs off the module. Here’s a single chip and the socket it should be mated to


Bend the pins and straighten them. I used a needle to pry the pins upwards a bit and did the rest with tweezers. Now you have the exact spacing of the pins on your chip. Use that for building a “pin aligning tool”. I’ve used a piece of plastic and a fine saw to cut 10 grooves into it. When done, it looked like this:


Now find something on which you can fixate the chip to (still being movable). I used a block of wood and a rubber band. This worked quite well. This way, you can always adjust the position of the chip when needed.
It’s time to cut some pins. For the start I went for about an inch long – place them into your self-made tool and fix them with a piece of self-adhesive tape (Scotch in USA, Tesa over here ;)).
Now put some solder on the chip’s pins as well as on the freshly cut DIY-pins.
Carefully position your tool so that the pins do have good contact.

If you did everything right, a short contact with the solder iron tip should be enough to solder the new long pin to the original one. When you’re done with all pins it should look like this


As you can see, I did already start to bend the new pins to fit into the socket. It’s a bit try-and-error to get the right angle. Be careful to avoid the pins touching each other or even break when being bent. Re-fitting a single pin can be a major pain in the a**!
Now you need to cut the pins into a reasonable length. First bend them into position – constantly checking against the socket. When all pins are ok – start cutting from one side to the other, bit for bit until you got the perfect length (Use the first chip as a model for others which might follow).

The seating is a bit difficult as you can’t use maximum force to push them into the socket. I used a fine caliper to actually pull the chip into the socket.

Due to the angle needed, the chip will hover quite a bit above the socket. I guess you can go lower if you go for a 90° bending – I didn’t have the patience.
Double check all connections from the original pin to the one on the socket. Also check for shorts!


Here you have it, the ugly Franken-Chip. But hey, it didn’t cost me a dime!
That said, after soldering 160 pins, bending them and carefully pulling them into their sockets… I guess I won’t do it again 😉

Tower of Power

Having the “Gerlach card” running, I was looking for ways to create something Transputers were made for: A farm, grid, network, cluster – call it what you like.

By a lucky incedent I was able to make contact to some people at DESY, which is one of the world’s leading accelerator centres. DESY develops, builds and operates large accelerator facilities, which are used to investigate the structure of matter. It’s comparable to the CERN accelerator in Switzerland.
I’ve learned that they were on schedule to switch-off a part of their accelerator, namely ZEUS (German), as all the planned research-protocols were finished… and I’ve learned that they use(d) several transputers for data aquisition and real-time analytics!
So after 2 years of shmoozing and sending ASCII-art flowers in mails, I was allowed to give their transputers a new home (else they would have been destroyed – oh my!).

I was surprised to see, that there was not the amount of transputers used as I would have expected (hundreds?). So no wonder they were able to replace the transputers by one single Linux box for the last year of the project, running the transputers as hot-standby backup.
But I also got all their spare-parts and everything else… a good start.

The original system consisted of 12 transputers, each on a TRAM, 4 of those sitting on a custom made TRAM-board called “TRAMWAY” which looks like this:


It’s not really worth calling it a board – It’s mainly a TRAM carrier with RS422 drivers for each link. The links for the TRAMs are hardwired, so TRAM1 has one “down link” (i.e. from the host or another card) connected to link0. Link1, 2 & 3 are connected to TRAM1, 2 & 3 respectively.

6 of those TRAMWAYs are currently sharing a case making it The Tower Of Power:


As you can see I stacked some TRAMs (Size-1 TRAM on a size-2 TRAM) to squeeze in the maximum number of TRAM… power to the tower, man!
Here’s another one showing the ToP with its host, an Intel LP486:

This is how the full power looks like in ‘ispy’:

Using 150 ispy 3.23 | mtest 3.22
# Part rate Link# [  Link0  Link1  Link2  Link3 ] RAM
0 T425b-20 239k 0 [   HOST    …    …    1:0 ] 136K.
1 T805b-25 1.5M 0 [    0:3    2:0    3:0    4:0 ] 4100K;
2 T800d-20 1.8M 0 [    1:1    5:0    6:0    … ] 1028K;
3 T800d-20 1.8M 0 [    1:2    7:0    8:0    … ] 1028K;
4 T800d-20 1.8M 0 [    1:3    9:0    …    … ] 1028K;
5 T800d-20 1.6M 0 [    2:1   10:0   11:0   12:0 ] 1028K;
6 T800d-20 1.6M 0 [    2:2   13:0   14:0   15:0 ] 1028K;
7 T800d-20 1.6M 0 [    3:1   16:0   17:0   18:0 ] 1028K;
8 T425b-20 1.8M 0 [    3:2   19:0   20:0   21:0 ] 132K;
9 T800d-20 1.6M 0 [    4:1   22:0   23:0   24:0 ] 1028K;
10 T805d-20 1.8M 0 [    5:1    …    …    … ] 1028K;
11 T800c-17 1.8M 0 [    5:2    …    …    … ] 2052K;
12 T800c-20 1.8M 0 [    5:3    …    …    … ] 1028K;
13 T800d-20 1.8M 0 [    6:1    …    …    … ] 1028K;
14 T800d-20 1.8M 0 [    6:2    …    …    … ] 132K;
15 T800d-20 1.6M 0 [    6:3    …    …    … ] 132K;
16 T800d-20 1.8M 0 [    7:1    …    …    … ] 1028K;
17 T800c-17 1.7M 0 [    7:2    …    …    … ] 2052K;
18 T800c-20 1.7M 0 [    7:3    …    …    … ] 1028K;
19 T425b-20 1.8M 0 [    8:1    …    …    … ] 132K;
20 T425a-20 1.8M 0 [    8:2    …    …    … ] 132K;
21 T425b-20 1.8M 0 [    8:3    …    …    … ] 132K;
22 T805d-20 1.8M 0 [    9:1    …    …    … ] 1028K;
23 T800d-25 1.8M 0 [    9:2    …    …    … ] 2052K;
24 T800d-20 1.8M 0 [    9:3    …    …    … ] 1028K;

Das Transputerbuch

There was one major german book about transputers called “Das Transputerbuch”, written by Uwe Gerlach (ISBN 3-87791-019-X).DasTransputerbuch
What made this book special was that it included an unpopulated 8-bit ISA card for a transputer and 1MB RAM, fully B004 compatible.
Additionally, there were schematics provided to build a host-adapter for several homecomputers of that time (C64, Apple II, ATARI ST and Commodore Amiga).

I was able to get one book off ePay which was still includung the printed circut board and a 360k floppy containing some sample sources and a rudimentary assembler.
So I’ve polpulated it, found some mistakes Gerlach made and made it somehow run.

This is how the card looks


It’s design is pretty simple – at least compared to the efforts been taken with the i860 cards on this page. The simple design is also because the Transputer has nearly everything included… so what you see is:

  • The right half is the ISA-bus and link interface. The rightmost and longest IC is a C012 connecting the 8-Bit ISA bus to link0 of the Transputer. Everything else are buffers & drivers.
  • The left half is -besides the Transputer itself- just 1MB RAM and some address-logic. The card would also work without having this side populated using the internal 2 or 4k of the Transputer.

C’est ca. As said, prety simple.

The mentioned bugs of the card are:

  1. The orientation of U11 and U12 are wrong on the print on the PCB and in the book, check the photo for them.
  2. There are no holes for the capacitor near to U28, you will have to solder it to the corresponding pins on the back of the PCB.
  3. The crystal oscillator U12 has its pin-1 not-connected, but it is connected to ground on the board. My crystal oscillator didn’t generate a clock signal, when pin 1 was connected to GND, although it normally shouldn’t matter.

Still, there was a persistent problem with the external 1MB RAM. It was detected by mtest but depending on the Transputer-type used and some randomness, it never was checked as being ok.
Replacing  some capacitors and strengthening some ground traces helped but it’s still not clear what the real reason was.

Here’s the back of the card – looking like a snake-pit now 😉