Tag Archives: ISA

Digging deeper into the highRISC

After 7 years mainly doing research on Transputers and the i860, I had the feeling it’s time to do some more digging into the highRISC card.
If you have read my initial post about the miroHIGHRISC (and the Tiger) you remember the undocumented 20pin socket on the card (pictured in the upper right corner):


Let’s have another look at the “UART port” again:

The pinout (the connector is rotated 90° counter clock-wise):

GND  oo  /WR0
D0   oo  INT2
D1   oo  /RD
D2   oo  /IOSEL
D3   oo  RESET (most likely)
D4   oo  A2
D5   oo  A3
D6   oo  A4
D7   oo  A5
VCC  oo  A23

Reading a bit of the BIOS’ disassembly, I stumbled across routines to talk to an UART.  A very common (D)UART of those days was the SCN2681. If you take a look at this chips specs, they perfectly fit to the signals provided at the HIGRISCs UART-port!

Here’s its pinout with the corresponding pins marked:


A2-A5 are used for A0-A3 on the 2681 and the only pin not directly represented is A23 which might be used to decode. Also, it nicely reveals that CPU INT2 is used for the UART.

The LR33000 datasheet tells me that there’s an 4MB IO-area starting at 0x1E000000 reaching up to 0x1EFFFFFF- most likely the 2681 will live there… and the corresponding signal called /IOSEL is available on the UART-port (and will perfectly help as chip-select decoder). Tadaa!

So after the UART we need to get the RX/TX signals to a higher level, i.e. the +/-15V of RS232 – this is the call for our old friend MAX232.

[current bread-board experiments sadly didn’t yield into ‘instant success(tm)’… I’m missing out something – need more time to investigate]

Bootcode / BIOS

The LR330xx CPU also has an /EPSEL EPROM select signal, indicating it’s accessing an EPROM expected to start at 0x1F000000 and ends at 0x1FFFFFFF (4MB right below the IO-area).
Using this knowledge and knowing that the MIPS standard boot-vector is at 0x1FC00000, it’s easy to feed the ROM-dump I did some years ago into the disassembler with the correct start address to do his job.

We need to get an understanding of this bootcode first, so that we can get an idea of “what is where” (e.g. ISA bus, UART etc) and later upload our own code and use those addresses.
Just to stick my head a bit into the clouds, the aim is to first port a then common MIPS monitor-program called ‘PMON’ and use that to run some sort of μLinux. But that’s probably another handful of years ahead…
PMON was a good source of information, because it’s originally written by LSI, supporting all the LSI eval-boards. Lo and behold, some of them had a 2681 UART, too… located at 0xBE000000, which is extensively used in my BIOS disassembly  😉
I have a certain feeling that miro borrowed some design ideas from the LSI Pocket Rocket evaluation board (don’t Google it, it’s a mythic being – if you have documentation, mail me!).

So this is the 2681 memory-map then:

#define BASE_2681 0xbe000000
#define SRA_2681 ((1*4)+BASE_2681) // 0xbe000004 status register 
#define THRA_2681 ((3*4)+BASE_2681) // 0xbe00000C Rx/Tx holding register 
#define ACR_2681 ((4*4)+BASE_2681) // 0xbe000010 Aux contrl. register 
#define ISR_2681 ((5*4)+BASE_2681) // 0xbe000014 interrupt state register 
#define CTU_2681 ((6*4)+BASE_2681) // 0xbe000018 Counter timer upper 
#define CTL_2681 ((7*4)+BASE_2681) // 0xbe00001C counter timer lower 
#define START_2681 ((14*4)+BASE_2681) // 0xbe000038 start timer 
#define STOP_2681 ((15*4)+BASE_2681) // 0xbe00003C stoptimer

Using those addresses we should easily identify the comms routines.

Something happens at 0xBE800000 which seems not UART related. So that’s probably the reason why A23 is available on the connector. That way we can ignore access to that address by OR’ing it with /IOSEL to create a /CS.

The DOS side of things

The tool to load a MIPS executable into the HIGHRISC is called DL.EXE. Loading the test-program prints this to the console:

miroHIGHRISC download program. V 1.00
(c) miro Computer Products AG , Germany

CONFIG: I/O-register-address: 0x368 
CONFIG: DRAM - base-address : 0xD000 
CONFIG: DRAM - size : 8 MB
CONFIG: TIGER - RAM - size : 8 MB

Resetcount = 87340

Loading test.zor
text : start=0x80030000 size=0x52c0
data : start=0x800352c0 size=0x520
bss : start=0x800357e0 size=0x150
entry : 0x800301a0
TIGER comm.address : 0x3ffd00
max_used_address : 0x35930 
real_DRAM : 0x800000 
Heapsize : 0x7CA6D0

test.zor sucessfully downloaded.

This gives us valuable information. The DOS-side uses the IO port 0x368 and has a memory window of 16K from  0xD000 to D3FF.
MIPS programs are loaded to 0x80030000 and the 16K seems to be mapped to 0x003FFD00, just 128K below the 4MB boundary of the LR33k address space.

As usual – this is heavily work-in-progress. So this post will be edited while making any new progress. TBC…

TIGA – The basic stuff

Welcome to the TIGA basics page! The fist post in my little TIGA chapter.
You probably came here because you just got (or plan to buy) a cool, shiny TIGA card and like put it to some use. Or you’ve read about it and found out, that the Web is pretty thin on that matter… Anyway, you came to the right place!

Let’s check some points fist…


Well, if you have a card already, great, you’re set.

There were/are different versions around. The early cards used the first implementation of the graphics controller called TMS34010 chip which was clocked up to 60MHz (amazingly high!).
Later models used the advanced TMS34020 which started at 33MHz up to a max of 40 but had faster instruction cycle times, a faster memory interface and a twice as big instruction cache (512 bytes. Yes, bytes). Additionally the ‘020 supports the rare TM34082 floating point co-processor (actually even more than one) to speed up 3D calculation. I’m not aware of a Tool using that…
Every TMS340 has its own RAM to run “programs” in. Depending on the model this starts at 1MB and can sometimes expanded up to 17MB. Better cards used SIMM to do this, but there were some models which used  proprietary RAM modules which are nearly impossible to come by these days.
Next the TMS340 needs VRAM, the memory holding the graphics itself. Again, depending on the model, this might vary from 1 to 4MB resulting in different max resolutions. IMHO just 1MB doesn’t do a TIGA card justice. That is just enough for 640×480 in 24bit…
Finally, as TIGA was not a standard CGA/EGA/VGA replacement, you’ll need some way of displaying the DOS text/graphics output. TIGA was always meant as an additional display mostly using a 2nd high-resolution screen, so TIGA cards either run in parallel to an existing VGA card or it also features a (mostly simple) VGA controller for this.
Very sophisticated cards like the miroTIGER gave many options for this. It features a small VGA part (a Cirrus Logic CL-GD540 and 256K of DRAM) to make a 2nd card unnecessary or could disable that to use a 2nd card of your choice for a two-screen-solution or offered to loop-though the signal of an existing VGA card and automatically switch between them for a single-screen-setup.


So if you consider buying a TIGA card, go for a TMS34020 with SIMM sockets. It should have at least 1MB RAM and 2MB of VRAM. A SPEA Graphiti FGA is a good example for this minimum config.
While DRAM isn’t that important, the more VRAM you have, the better. Having a VGA controller on board might be desirable if you’re tight on slots – but to my knowledge the best VGA controller ever used on-board  was an ET4000. So it’s more or less a matter of taste.


Actually this is the more important point on your list. While yes, TIGA is a standard, it contains certain proprietary parts, called the CD, GM and EXTPRIMS you’ll need to get your card going. The reason for this is the driver which is more a layer model looking like this (listed bottom-up):

Application using TIGA (e.g. AutoCAD)
application specific extensions (also *.ALM/*.RLM file)
extended primitives (EXTPRIMS.RLM/*.ALM)
Graphics Manager (e.g. tigagm.out)
Communication Driver (tigacd.exe)


The 3 yellow(ish) levels are card-dependent, so without them, you’re lost and your shiny TIGA card just makes a nice paperweight.
The lowest level is the Communications Driver, or CD for short, is 100% hardware dependent –  It is always supplied by the cards manufacturer and, well, handles the low-level communication and resides in the PC (upper-)memory.
Above that sits the Graphics Manager (GM)- this is the “real thing™”, the core or kernel of TIGA – which is the firsts thing being loaded into the cards own DRAM.
On top of the Graphics Manager sits another layer belonging to the package provided by the card manufacturer and loaded into the cards RAM, the Extended Primitives Library called EXTPRIMS.RLM in 99% of all cases. This contains all the drawing routines for primitives e.g. boxes, circles but also printing text etc. The file extension ‘RLM’ stands for relocatable load modules while ALM means absolute load modules. RLM’s are loaded and linked at run time, ALM’s are linked in advance for a fixed configuration and later at run time just loaded onto the TIGA card.

Here’s another illustration to show the layer model separated by memory regions:

With these 3 layers loaded, your TIGA card is ready to rock and awaiting commands from your application. Let’s take AutoCAD as an example – it’s probably the best example anyway as TIGA was mainly used for CAD.
It will not only load the TIGA driver but probably also some extensions provided by your cards manufacturer. So for example the miroTIGER came with a 3D-Viewer called “MulitVIEW”, ELSA provided a tool called ELSAVIEW with their Gemini cards etc.. All those tools loaded some extra code into the cards RAM (that’s the light blue layer).
All the extension tools I saw up to now didn’t require more than 200KB RAM. The TIGA core itself is at ~100KB, so for most basic stuff 1MB might suffice at first – but of course some of those tools need extra RAM for holding data so my assumption is that 2MB are a good bet to start with.


All that said, be aware that were two main versions of the TIGA kernel – V1.x and V2.x which have slight differences in programming. Again, it depends on the model of your card which TIGA version is supported. As far as I know, V2.x (2.2 being the latest) requires a TMS34020.
ALM’s were a unique feature of TIGA V1.1 and should no longer be used with TIGA V2.0. Generally, V1.x programs do not run (properly) on a V2.x CD/GM combo.


First, most likely there might be something to setup on your card. DIP switches for example or jumpers. At least you need to know/set the base-IO address of your card. Lucky are those who have a manual 😉
Next, as this is DOS-land, there are some things to set-up in your config files. As usual with DOS, you have to set an environment variable in your AUTOEXEC.BAT:

SET TIGA=-mC:\TIGA -lC:\TIGA -i0x60

This defines the path(es) to your TIGA modules and libraries as well as the base-IO address, at which your card is communicating. This has to be adjusted to your hardware setting.
Also the base-path to your TIGA files needs to be in the system path.

Then you load your CD and (optionally) GM:


The 1st line is clear – if your config allows, you can load the CD into upper-memory. With the 2nd line you can pre-load the GM into the cards RAM and the -LX parameter makes sure it eXecutes right after that. This step is optional, as well programmed TIGA programs check for the GM and if it’s not loaded, they’ll take care of that.

That’s about it. Yay, your TIGA system is up and running 😀 and you’re ready for some action. The next post (in the works) will then show TIGA “in vivo”… so stay tuned!
[in the meantime have a look around – many other cool vintage things to discover on this page]

Inmos B008

Introduced at the sunset of the Transputer era, the INMOS B008 was the successor of the B004 of which it dramatically differed:

  • 16-bit ISA connector (for Interrupts/DMA, it’s still an 8 bit data path)
  • 10 TRAM slots
  • C004 and T2xx on board

The usual source provides the full manual/documentation… down to the GAL equations.
All these enhancements enabled the B008 to create simple, yet powerful Transputer networks on a single expansion card and still makes it the perfect platform for todays Transputer retro experiments/fiddlings.

Here’s a late “Rev.F” version of the IMSB008:


The previous revision E had a ceramic version of the T2xx and used GALs instead of the CPLD you can stop in aboves picture.



Obviously the Inmos B008 had clones as the B004 did.

Transtech TMB08

Well, I guess there’s nothing which Transtech did not clone and/or improve…
In this case they used a AMD MACH CPLD from the beginning, a PLCC version of the T225 and everything else was SMD.


Alta SuperLink/XL Transputer PC Card

Alta Technology was a spin-off of Computer System Architects (CSA).
The SuperLink/XL board used TRAM modules like the Inmos B008, but featured a 20 MHz IMST225 Transputer to handle external interfacing and a beefed-up host interface design. Like the B008 it supported 10 TRAM’s

Altacor SuperLink XL


Actually I wasn’t aware that ARADEX also made TRAM carriers… One of my first TRAMs was an ARADEX one, so this is a first for me, too.
Their interpretation of the B008 theme features just 8 TRAM slots (vs. the 10 “standard”) which are strangely enough sorted in ascending order (0-7) and not like the B008 order of 1, 5, 6, 2, 0, 4, 7, 3, 8, 9. Also the TransAT provides two 9pin D-subminiature connectors in contrast to the B008s 37pin connector – most likely its layout is the so called Aalener Link-Interface. That includes the RS-422 differential drivers and receivers next to the connector (AM26LS23’s and AM26LS33’s).

Concerning other parts, besides an C012 they used some sort of CPLD – presumably to control the 16 bit bus – in the photos I have, I can clearly see the traces coming form the ISA Bus’ D[8-15].
It also uses the IRQs 10-12.

Last fun bit: They named the two GALs with their JED filenames. Very handy 😉


Other Transputer interfaces

This is the collection of other Transputer interface cards (i.e. not from the usual suspects) I came by here and there. And no, I don’t actually own them all.
Some are rare, some are odd, may are cool and most are all three of them 😉

This post will be irregularly updated as new finds come along…

Pixar Transputer Card

Yes, that’s true. Pixar built its own Transputer interface back in the days, simply called “Render Accelerator”. Nomen es omen 😉
In constant search of raw computing power they tried out everything, eg. Intels i860 and others. It was just another logical step to try speeding-up Pixars Renderman package by using a Transputer farm. As an early adopter, they had to build their own stuff to suit their demands. Here’s a very interesting read about the long way Renderman came from and which hardware they’re were using. This article about texturing techniques is mentioning this card on pp.16.
The mentioned Jeffrey Mock was also quite busy during his Pixar days in helping Logical Systems (LSC) by writing a concurrency library for their C-Compiler.

Here’s the front of the full-size 8bit ISA card – filled up to the brim.
It features two T800-20 Transputers, each having its own 4MB of RAM. Two links are facing the outside-world – I presume it’s been meant like a up- and down-link to the next card.
The rest is standard early-days ISA bus, C012, Transputer DRAM design.


No much to say about the back side. The silkscreen is a bit uncommon, but it’s nice when it comes down to repairing… and some “burning” shows, that seemed to be the case with this specific card.


The Quintek T9

This is a very manly approach into transputing matters… don’t give me that step-by-step upgrading of an Transputer array. Just do it once and do it right 😉


Yes, that’s 9 Transputers, each with 1 or 4MB RAM and a C004 all directly soldered onto that 8-bit ISA card. It sure was expensive…
While there’s a C004 (the 6th golden IC from left), there’s no T2xx to control it. So I assume that one of the T800 is in charge to configure it… or this is done through the ISA link-interface as there are two C012 on the card,


The YARC ProTran

This is a fullsize 16-bit ISA card from YARC. It features 4 Transputers with the option of supporting them with a (for the time) big amount of RAM.


The ProTran board can be equipped with 1 to 4 Transputers. The root Transputer (the rightmost) can have acces to 1-16 megabytes of RAM – it’s 8 in this picture. Each of the other three can be configured with 1 to 8 MB. That was very serious stuff back then.
What’s most interesting about this card is that YARC  didn’t gave much about standards and went a proprietary route in many places:

  • A proprietary bus interface is said to provide a peak I/O speed exceeding 1 MB/sec
  • All links, event inputs and subsystem control signals are fed to a proprietary pin-field array.
  • The memory design uses a multibank and interleaving technologies to achieve zero wait state performance

All this explains the excessive use of GALs in the lower half of the card. Beside the proprietary approach the ProTran offered a compatibility mode (read: B004 interface) to use standard INMOS tools.


CSA (Computer Systems Architects) was big in the educational market and produced smaller, better integrated B004 compatible Transputer cards. The higher integration of DRAM parts allowed half-length ISA cards meant for evaluation or as a starting point for building bigger systems later.
(The following pictures are courtesy “the PCPUTER” page. Permission to repost them were kindly granted)

Meet the “Transputer Kit PC Card” –  They came bundled with a slightly restricted version of the Transputer Toolset, together with a great manual which described lots of different programming and hardware interfacing lab-type experiments.  These cards used standard multi-pin circular DIN connectors/cables to route the link and reset signals, and provided the first hands-on introduction to distributed parallel processing for many people.  They included a “budget” T400A 32 bit non-floating point processor, and off-processor memory was an option

CSA Kit Board

This is th PART.1 four processor board – mainly a carrier for CSAs proprietary Transputer Modules (like INMOS’ TRAMs), and the single processor PART.2 board featuring a PC interface.

CSA PART1 and PART2 System

The “Gerlach card”

The card from the book “Das Transputerbuch” from A. Gerlach is a typical example. It has its own post on this page.<
Very simple design but only 2 layers and completely documented in the book.




Hema TA2

The Hema TA2 is some very special specimen of ISA interface cards. IMHO it’s the last and most sophisticated interface you can run in an ISA bus. These are the feature highlights:

  • 16 bit ISA interface
  • half-size card
  • 4 TRAM sockets
  • TTL and RS422 link connectors (if RS422 drivers are fitted, TTL is not usable)
  • B004 compatible ‘Fast Mode’ as well as 100% vanilla ‘Slow Mode’

The TA2 implements an Idea which can be found in some documents from those days, about getting the maximum speed from the sluggish ISA bus and a link-interface chip like the IMS C011/012:
Overlapping acknowledge by using FIFO buffers and a controlling FPGA.

This is how the TA2 looks like:


I’ve marked the the important parts with colors/arrows:

  • red arrow – the IMS C012
  • orange arrow – the IMS C011 connected to
  • blue – two 1KB FIFOs controlled by
  • yellow – a MACH 110 CPLD and
  • green arrow – a PAL
  • purple – a XILINX 3030 FPGA doing the control logic
  • cyan & magenta – TTL and RS422 link connectors

And here’s the block-schematic using the same colors:


The schematic also mentioned the two other cool features of the Hema TA2:
Four TRAM slots and the “hema LINK-Bus”, a proprietary two row DIN 41612 connector which provides all links/subsystem which were used otherwise by the 4 TRAMs.
Finally there is a 4-bit microswitch (upper right corner) to set a unique ID for the card so you can identify up to 16 cards in a single system.


Using the provided control program “CTA2” everything can be set by software, e.g.

  • Base addresses for the fast- and slow link (0x150/0x158 by default)
  • Swapping fast/slow link configuration
  • Linkspeed for every link (fast/slow/TRAM/hema-bus)
  • Up- /Down-subsystem control
  • Interrupts per link
  • Waitstates

All the hardware wise ‘jumping through hoops’ still doesn’t do the job alone. To reach the ultimate ISA speed (the docs are talking about up to 1mbps) the communication needs to be tuned, too.
Lets talk a bit x86 assembler here (ahhhh), and DOS-only for sure:
It’s not enough to use simple in and out port instructions and constantly poll the C011/12 status register – that’s way too slow. You’ll need to go for the string variant(s) ins[b|w|d] combined with the rep instruction. Here’s an example for a C insb wapper function:

void insb(UINT16 port, void *buf, int count)
   _ES = FP_SEG(buf);   /* Buffer Segment */
   _DI = FP_OFF(buf);   /* Buffer Offset  */
   _CX = count;         /* Bytes to read  */
   _DX = port;          /* from Port xy   */
   asm   REP INSB;

Same goes for outs[b|w|d] respectively.  But there’s another extra to care for: The TA2 provides special  registers to give you deeper insight into its status, e.g. FiFo fill-rate (empty, half-full, full), FiFo interrupt settings.
So in effect, you couple the fast ins/outs instructions with interrupts attached to e.g. input half-full and output full.

That said, there are some caveats. ins[b|w] and outs[b|w] are supported from the i8018x and V20 on.  insd and outsd needs a 386.
And then there are possible speed penalties with 32nit processors (i.e. 386 and up) as they optimized the port instructions for virtualization (Virtual 8088 mode, not todays VM!) resulting in 100+ cycles per call.

So when everything is 100% optimal, hema says in its documents these are the possible transfer speeds to reach:

Function/Array size 1K 10K 100K 1MB
Read FiFo 150kB/s 390kB/s 570kB/s 615kB/s
Read Polled 160kB/s 160kB/s 160kB/s 160kB/s
Read Direct 600kB/s 610kB/s 610kB/s 610kB/s
Write FiFo 565kB/s 600kB/s 610kB/s 610kB/s
Write Polled 160kB/s 160kB/s 160kB/s 160kB/s
Write Direct 610kB/s 610kB/s 610kB/s 610kB/s

FiFo – Using interrupts and syncing status of fill level.
Polled: Each byte is synchronized with the C012 status
Direct: Like FiFo but no syncing.

Well, this has to be proved yet. Seem I need to write a benchmark… someday 😉

Inmos B004

I’d call the Inmos B004 the “mother of all Interface cards”, simply because it was the first ISA card sold by INMOS. And it wasn’t just the card but it also defined the (PC) standard of the software interface, mostly called the “B004-interface”. What a surprise 😉

So being the first card, it is quite big (full ISA length) while not offering really impressing specs: 8bit XT Bus, just one Transputer –TRAMs weren’t invented yet- and a max. of 2MB RAM (DILs). To do it justice, the manual rightfully calls it “Evaluation Board” and for that purpose it’s totally fine – remember that 2MB were quite an amount of RAM back in 1984.
To create a multi-Transputer network you had to either plug-in multiple B004s or connect an external network to the onboard connectors (the blue ones in the picture below).

As mentioned, the B004 software interface is what makes this card a keystone in the Transputer universe. All communication to the host (i.e. the XT/AT compatible PC) is done through a port range normally beginning at 0x150 (base, can be moved by some cards).
With certain offsets the host software can communicate with the Transputer, or the C011 to be precise:

Base Address Register Comment
+0x00 C011/12 input data  read
+0x01 C011/12 Output data write
+0x02 C011/12 input status register read = returns input status
write = set input interrupt on/off
+0x03 C011/12 Output status register read = returns output status
write = set output interrupt on/off
+0x10 Reset/Error register write: Reset Transputer & C011/12 and possibly subsystem (check manual)
read: Get Error status
+0x11 Analyse register  (un)set analyse

This mapping was used by more or less all ISA interface cards and extended by other more sophisticated interface cards later.


Needless to say, that very soon there were a couple of “inspired” models from other manufacturers. AFAIK all of them support Transputers up to 30MHz, which the B004 didn’t… so they’re actually better.

This example is from Microway (yes, those guys who later build the i860 Number Smasher), named Monoputer and dated 1987. Up to 2MB could be used on it. Mind the connectors being accessible from the outside:


Later they produced the “Monoputer 2” which was more modern and used SIMM RAM modules instead of DIL parts. The Transputer and Linkinterface moved into the middle of the card and the link connectors were moved inside the pc case again – the connectors are the very same used on the NumberSmasher860:


And here’s the one Transtech made, calling it TMB04 mind the SIMM banks which enable the card to give home up to 16MB RAM (at 3 cycle speed!):

Transtech TMB04

The DSM-860 Series

Based on a public project from Rolf-Dieter Klein and Tobias Thiel (“PC-Karte mit i860”) in the German computer magazine “mc” (2/90 to 7/90), the Munich based company DSM built several i860 boards for the PC/AT which they called the DSM-860 series.
All DSM-860 have one thing in common: They offer a high level of hardware features – no costs were feared. So naturally, those cards were not cheap. But you really got something for your money. All versions featured

  • 4 Transputerlinks for networking multiple cards
  • Connection to the hosts system-bus (ISA/EISA) via dual-ported RAM
  • A 16-bit bus is also available via dual-ported RAM on special connectors giving a throughput speed of 8MByte/s for high-speed connections between several SPC boards.
  • RAM was put on an extra RAM board making the complete SPC-860 a double-card sandwich


The 1st incarnation was the SPC-860, very quickly renamed to DSM-860, an 8-bit ISA card with 4MB RAM (DIL) and 4 10mbps Transputerlinks via four C012’s (polled by the i860 resulting in 740kbps linkspeed).

Here’s a picture from a 1992 ad, with separate RAM card attached:


It did cost 16450 DM including the (GNU) C compiler and assembler.


Next, they released the DSM-860/16 (renaming the DSM-860 into DSM-860/8) being a full fledged 16-bit ISA card. It has a real Transputer (16bit T222, having its own 32K SRAM) for handling the “multiprocessor communication” and is able to support up to 256MB on a sandwiched daughter-board, now using SIMM modules instead of DIL parts.
The Hitachi HD63310 dual-ported RAM, used in the 8-bit version to communicate with the host was replaced by faster Cypress IDT7130 types (“because of the high speed of the 16-bit ISA interface” ;-)), resulting in a peak-rate of 14MByte/s.

Here’s the schematic of the card and its components


This is how it looks in reality… my DSM-860/16:


As you can see, the card is not exceptionally high integrated – even built 1992 there is not a single SMD part used, everything is socketed, only some PALs could be called “custom parts”. But this does not necessarily mean it’s badly designed or build.
If you have a close look (click the picture for a bigger version), you’ll see that every part/socket/jumper on the board is nicely specified in the silk-screen printing. All GALs and the EPROM contents are available in the documentation… which has 426 pages by the way.

Here’s the left side in more detail:


This end of the card is the “external comms” side. Beside the all-mighty i860 you can easily spot the golden Transputer being the communication controller.
To its left, there’s the first dual-ported RAM (1k x 8) connected to the socket for the external bus (Ring-A, located on the edge above). Below that are the two 16k SRAMs -marked MHS- for the Transputer. Then to the right are the two dual-ported RAMs (a 7C131 and a so-called slave 7C141) making the 16-bit connection to the i860’s bus. The rest of the parts are quartz oscillators (5MHz & 40MHz) and drivers/buffers for the buses. On the top edge next to the Ring-connectors you can spot the 4 Transputer links (JP9-12).

The right side is comparably boring:


The boot EPROM, 6 GALs, again two dual-ported RAMs (this time for the ISA-bus connection) and some buffers… well, and 5 LEDs. LEDs are good. 😉
Also, you can see the pin-row connectors at the lower edge and on the left of the photo. That’s the expansion-bus. The lower connector is more or less 1:1 the ISA bus, the left one is a 16-bit bus to the i860. AFAIK, they never offered an expansion for sale.
The last (but not least) interesting thing on this picture is the copyright. Yes, it’s a DSM860/16 from 1992, RDK made it (Rolf-Dieter Klein), DSM in Munich distributed it – but it’s obviously also a rev. 1.6, which means there could be others before or after that one. If you have more informations I would be happy to learn more.


I’m pretty sure there was one more version after this rev.1.6, this b/w picture from a DSM press release about shipping the 250.000th slot-CPU card shows a very changed design. The silkscreen print says “DSM860-OEM/16”, so it’s obviously nothing for the normal market.
Mind the onboard-RAM, the missing comms-section and the high integration (SMD parts all-over) and even an early form of an FPGA from Lattice – my assumption is that this version could be the answer to the Kontron SBC860 showing nearly the same layout:

At least this ‘riddle’ is finally solved. I was able to buy an DSM860-OEM/16..Yay! As assumed, it is a modern (for 1990 standards) version of the DSM860-16 now consisting of just one board, so no more RAM card as described below- and without the Transputer and Ring-A/B stuff.

Here are my pictures of it. First of all, the card in full view:


The right half shows a very high degree of integration compared to its predecessor. All DIL ICs were replaced by SMD parts and lot of logic went into PALs and even an FPGA (The contents of the EPROM is the same as with the other card, minus Transputer handling):


The left half contains the CPU and the RAM. This time only 8 SIMM slots:


The RAM card


This is the 2nd part of every DSM-860 – the RAM card (except the OEM-16). Same dimensions as the SPC itself… i.e. full length. The biggest part of it is consumed by the 16 angled SIMM sockets, obviously interleaved, thus named altering slot-a & b. Only the 8 a-slots are populated on mine.
The rest of the board is used for lots of buffers and drivers, some GALs (doing the mem-mapping) and there’s quite a big copyright… again.


One typical detail of those days is the fact that manufacturers were not very keen on having users doing upgrades themselves. Even this RAM board has standard SIMM sockets and one could simply plug in more SIMMs to expand the RAM you had to change a GAL (the one in the lower left corner with a while label saying “UXM24Wxx” on it). Obviously these GALs are the only ones notdocumented. All I know is that there were 3 GALs available differing in the last two letters of the label:

  • 8B = only a-slots can be used by either 1M or 4M SIMMs giving 8 or 32MB total
  • 16 = both a- and b-slots used with 1M SIMMs = 16MB total
  • 64 = a- and b-slots filled with 1M and/or 4M SIMMs giving 16, 40 or 64MB total.

Because the card as well as the documentation says the maximum supported amount of RAM is 256MB there might be the chance of supporting 16MB SIMMs – I did not try this yet.

Both cards attached together give quite a big and heavy sandwich


It’s obvious that you not only need 2 full-size slots but also guide-rails inside the case to hold the weight of this beast.


This seems to be the king of the SPC hill. Technically it’s pretty much the same as the DSM-860/16 but this time featuring a 32-bit system bus – namely EISA. The EISA bus was a dead-end like IBMs Microchannel but comparably easy to implement and free of license fees.

So the main difference to the DSM-860/16 is the 32-bit wide connection to the hosts bus, visible by the 4 dual-ported RAMs used for a 32-bit wide connection to the EISA slot.

Again, here’s a 1992 magazine ad showing a probably early version of the card as the marking says “DSMß860-32” (mind the beta) and the year “1991”:


Compared to that, my version (1.2) does not look that much cluttered – also the Transputer comms part were moved to the left side of the i860 and two more LEDs were added:


So the left side of the card looks pretty identical to the DSM860-16, while the right side has a bit more logic to satisfy the EISA standard, the already mentioned 2 more DP-RAMs, a bigger expansion-bus due to the EISA slot and most important: 2 more LEDs! Did I mention that LEDs are good? 😉


This more detailed picture shows that the DSM860/32 was released the same year as the ISA version. This card is a rev.1.2 – again, if you know more about revisions, I’d be happy to hear from you.
You might have spotted that this card looks a bit shabby. That’s because it was pulled from some universities dumpster. It was missing some components and had some “scars”. The good thing was that none of the GALs were missing and due to the fact that every piece is documented on the card it was easy to replace the missing parts.
On the above picture you can clearly see e.g. the 100nF capacitor C40 below the i860 or the 40MHz OSC. I wish everything would be that well documented.

The Infinity card

This is a rare and mysterious beast. The documentation only touches it very briefly. It’s definitely nothing been built for the average DSM860 user – if something like that existed. For sure it was extremely expensive… and it has LEDs 😀


So at the first look you see 2×3 connectors for 40pin cables – the same used on the DSM860 cards (Ring-A and -B). Then there are a lot of drivers and buffers and a big Lattice pLSI 1032-50 which is a 6000 gates PLD (Programmable Logic Device). A closer look to the board gives more hints – thanks to the DSM (or RDK) habit to print as much info as possible onto the board:


Ok, first information we get is that this is a EINF860M or INFINITY 32Bit Extender. It’s like all other boards (c)1992 by DSM Munich and -as one would expect- designed by Rolf-Dieter Klein (RDK).
The three connectors are labeled ADDR(ess), DATA MSB (Most Significant Byte) and DATA LSB (Least Significant Byte).
The the right of the connectors is an Intel 85C098-20. I think that’s a One-Time-PLD, not 100% sure.

My educated guess is that this card is what the print on it says: A bus extender. Using the 16-Bit bus on the DSM860 cards one can build quite a big parallel computer. But the max. length of the flat-cable to connect each card with the next one is limited. So this card would be connected to other DSM860 cards in the same case (i.e. a 19″ case in a rack) and the extender would then “amplify” the bus-signals to be send over into the next rack full of DSM860 cards.
That said, my fear is, you’ll need two of those cards as the seperation of Adresses and Data (MSB and LSB) is nothing being used on the DSM860 cards. So my next guess is, that the INFINITY communicates over the EISA bus with the other cards and has its own external bus. Again – I’m happy if you contact me if you know more/better!


This is indeed a very rare breed – I was informed that less than a 100 of those were sold. Built in the end of 1992 as “Project Zorro” by the German company miro (bought by Pinnacle in ’97) it took the same line as all the other accelerated graphic cards in those days: Highspeed graphic -mostly TIGA- plus some speedy general purpose CPU. The SPEA cards using Intels i860 were direct competitors for example – I was also told that miro also looked into using the i860 but scrapped that attempt in an early stage in favor for the HIGHRISC.

The Miro HighRisc -or miroHIGHRISC as they wrote it back then- was a full-length 16-bit ISA card containing a MIPS CPU and a maximum of 32MB of RAM.

Technical facts:

  • 33MHz LSI LR33050 CPU which is a R3000 clone including the R3010 FPU minus MMU
  • 1k data- and 4k instruction caches on-die
  • 33 MIPS / 33 MFLOPS
  • 8-32 MB RAM plugged into up to 4 SIMM slots
  • 32 bit bus to connect the miroTIGER graphics card (100MB/s)
  • 2D: 150000 Vectors/s of 10 pixels length
  • 3D: 10000 triangles/s of 100 pixels, flat-shaded
  • 6000 triangles/s of 100 pixels, Gouraud-shaded

miro claimed that the HighRisc would deliver nearly twice the performance of an i860/33 solution with “real-world” applications (namely AutoCAD 12). That has yet to be proven but sounds reasonable given the limitations the i860 had when used as general purpose CPU.

Here’s the HighRisc in its full glory:


Interestingly, there’s next to none information on the Web about this card. Probably due to its high cost (5700DM) and the failing TIGA standard.
Here’s a nice snippet from an interview (in German) from 1999 with the original product manager Frank Pölzl:
Q4. What was your biggest flop?
miroHIGHRISC, a 3D-graphic card with MIPS and TI-Graphic-Processor.

Another tasty detail is that according to a news-snippet from the German magazine c’t (12/99, p.22) this card was developed in cooperation with Silicon Graphics (SGI) which bought MIPS some years before. Maybe this was SGIs first and last attempt to get a foot into the PC market?
Yet another interesting fact: The LSI 33k CPU was later radiation hardened by a company called Synova Inc., rechristened as “Mongoose V” and as such traveled into space several times… even to Pluto!

Here’s the left side of the card in more detail. It contains the CPU and the BIOS (32k EPROM dump available here) lots of 74-logic ICs, GALs and some MACH PLDs.
At the top-left corner of the picture below you see the connector to the miroTIGER, a TIGA graphics card described a bit further down on this page.
Also, there’s  an undocumented 20-pin connector at the upper-right edge of the card. This might be the 16MB/s interface “to connect peripherals like laser printers or repro-devices” as mentioned in the c’t article. Thinking about it – it’s an interface to an UART. This will be a nice project to do further investigation.

The pinout (the connector is rotated 90° clock-wise):

GND  oo  /WR0
D0   oo
D1   oo  /RD
D2   oo  /IOSEL
D3   oo  (unknown)
D4   oo  A2
D5   oo  A3
D6   oo  A4
D7   oo  A5
VCC  oo  A23


The right side of the card is dominated by the 4 SIMM slots which, according to the manual, support up to 8MB each. Also there’s a DIP-switch for setting up the address-range etc.


Even it has nothing to do with MIPS, the accompanying graphics card miroTIGER fits in quite good here. This card was meant to run for itself or accelerated by the above described miroHIGHRISC. This is what it looks like:


Following the TIGA standard it naturally features a TMS34020 graphics processor. This processor has its own RAM to do all the calculations, display-lists and fonts. Because TIGA was completely incompatible to the usual CGA/EGA/VGA standards you had to have such a card installed in parallel to see all the DOS/Windows outputs before switching into TIGA-mode. The normal setup was to have a 2nd high-res (1024×768++) monitor connected to the TIGA card then.
More advanced cards like the miroTIGER also had a VGA chip on-board, which saved you a slot and all the extra hassle. So let’s have a look at the details:


This is the left side of the card. The nice golden chip is of course the TIGA processor. Next to it there’s a National Design V2000 chip – most probably an ASIC doing all the RAM handling and stuff.. accidentally I stumbled across a notion of a “National Design Volante2000” TIGA card. Smell the relation here? So my most recent assumption about this is, that’s a somewhat standard TMS340 glue-chip, licenced by National Design to other TIGA card manufacturers.

The SIMM above is 8MB of RAM for the TMS340. Depending on the PAL (labeled 2004, 2044 or 2084) on the lower edge of the card, one could use 0, 4 or 8MB of RAM.
On the upper left corner is the connector to the miroHIGHRISC card as well as an impressive row of DIP switches.


The right side is mainly occupied by 4MB VRAM for the TMS340 as well as the TI RAMDAC in the upper right corner.
Below is a very simple onboard VGA controller by Cirrus Logic (CL-GD5401 aka Acumos AVGA1) and next to it its puny 256k DRAM – which is the maximum a GD5401 can address by the way :-/

This is a good place to post a big thank you to Peter Huyoff – the wonderful guy who saved my life while doing the ‘research’ on this card.
As you might spot in the picture above, there’s one chip broken… a tiny 74AS74 flip-flop – try to find a single SMD AS74 these days. It’s impossible if you’re not prepared to pay $50 b/c of minimum order fees! And no, an F74 doesn’t do it, it’s still too slow. Been there, done that.

Peter provided me another working miroTIGER for free! That’s the spririt between real men! And Peter is definitely one of them!

The SPEA cards

Between 1990 and 1995 the German multimedia-card manufacturer SPEA was one of the leading companies in this sector (When ATI was comparably small and NVIDIA not even founded).
They offered a wide range of display-cards, from a simple ET4000 up to very expensive CAD/CAM cards using various graphic chips like the TIGA controllers, Hitachi ACRTC and… of course the i860.
Later SPEA was bought by Diamond Multimedia (still in business) and some employees started their own company to finalize the graphic chip they already started to design when being with SPEA (read more here and here… both articles in German, sorry).

Two SPEA cards using the i860 were built. The first was the



This full-size ISA card features a 33MHz i860 with 4MB own RAM as well as 2MB VRAM. An Inmos G364 graphics controller is in charge for creating a picture on the monitor – BTW that’s the last and fastest graphics controller which was manufactured by Inmos.
Theoretically, this card could be called an INMOS B020 on steroids.

As this is “just” a 3D subsystem, a standard VGA was still needed for all 2D stuff. Its video signal was then looped-through the SPEA Fire… just like the Voodoo cards did it some years later.

A recent photo I’ve fond on ePay shows, that there was a proprietary memory expansion available, which has to be plugged next to the i860. Probably expanding the RAM to 8MB, which seems to be a considered a reasonable amount of RAM back in those days.


Interestingly the manual briefly touches the possibility to be programmed with own applications using Intels APX system. Sad enough, the APX is not included on the driver disks and was sold seperately… for a lot of money.



The FGA860 is the bigger brother of the SPEA Fire. Actually it’s two boards sandwhiched together: The one on top is -again- called the Fire-Board. But this time it is designed completely different. There is no RAMDAC or such… just the i860, RAM (16MB) and some custom- and bus-logic.
Behind this, there’s a full-blown TIGA card called FGA-4E, using a TMS34020/32Mhz with 4MB DRAM and 2MB VRAM. Not so usual is the also included VGA part on the FGA-4E. This way you can save an ISA slot for the needed VGA card.

The Fire-Board was available for 5700 German Marks, the FGA-4E added another hefty 10.820 Marks making a total of 16.520 Marks (1990/91 that was about US$ 8000)!
But for that money you got a “graphic subsystem” which was capable of 300.000 2-D vectors/s (10 Pixel long) and amazing 30.000 gouraud-shaded polygones/s (10 × 10 Pixels).
[Back then, that really was amazing… today every mobile phone might be better in 3D. Here are some numbers for comparison/amusement:
3DLabs GLINT 300SX: 500.000/300.000]

Here’s a view from the top… not really much to see. It’s very hard to pry those cards from each other. I guess, they were never intended to be separated again.


If you are in need of the drivers, I make them available here. It’s the IMHO most recent version from August 1994 including an AutoCAD 13 driver update.

Microway NumberSmasher

The US company MicroWay (also known for their NDP compiler range), presented an i860 ISA card called NumberSmasher 860.
It was available in two speed grades, costing 11698 DM (@33 MHz) or 14170 DM (@40 MHz). The needed compiler (C, Pascal or Fortran) was an 3135 DM extra.

This 16-bit ISA card featured an 40MHz i860, 4 or 8MB of ram and one INMOS OS-link controlled by a IMSC012 on a litte PCB, hiding 2 additional IMSC012 below it on the main PCB.
It is possible to connect one IMS C012 to to the ISA host bus to “feed” the Number Smasher 860 with programs and data (seedocumentation at the bottom of this page).

Here’s the board in its full beauty:


The left half is occupied by the 8MB RAM. The right half is all bus-logic, buffers and drivers. At the top is a very custom HD-connector – thanks to Jörg Heilmann I now know that this is the FiFo-Connector counting 100 pins. Again thanks to Jörg I also have4 pages of documentation to this connector which was designed to connect the FIFO I/O board (available as ISA and EISA version) to.

On a little separate PCB (having “LINK DR V2.0” printed on it) connected to P3 some sort of additional communication part was placed, consisting of an octal transceiver, one INMOS C012 link-adapter a PAL and an octal buffer featuring two 4-pin connectors (J1 & J2).

  • J1 – GND – GND(code) – to pin 3 of J4 – to pin 3 of J3 – GND
  • J2 – GND – GND(code) – to pin 16 of P3 – to pin 14 of P3 – GND

Additionally there are 3 configuration jumpers – function as far as my measurements go:

  • J3 – Connects pin 18 of the board-connector (LinkIn lower onboard C012) to either LinkOut of the C012 (jumper on upper pin) or to the 4th pin of J1 (jumper on lower pin).
  • J4 – Connects pin 20 of the board-connector (LinkOut lower onboard C012) to either LinkIn of the C012 (jumper on upper pin) or to the 3rd pin of J1 (jumper on lower pin).
  • J5 – Linkspeed for the IMSC012  (upper is 20Mbps, lower is 10Mbps)



As I have next to no official documentation about this board I would be very glad to hear from anybody who knows the tiniest bit about this card! AFAIK the original “manual” wasn’t bigger than 13 pages… pretty lame for a board costing as much as a small car back in those days.

Thanks to Jörg Heilmann, I got my first piece of original documentation: The 100 pin FIFO-Connector is described on these four pages. Not much but a start!

Here’s what I found out about the P3 connector on the board, having the “LINK DR” PCB plugged into it. If you have a look at the picture above, I’m start counting pins from bottom right continuing zig-zag like this:

26 oooo...oooo 2
25 oooo...oooo 1

1 – VCC
2 – CLK 5MHz
3 – Reset of the C012 (Pin 11) goes directly to the i860 reset-pin
4 – GND
5 – D7 from ISA Bus
6 – D6 from ISA Bus
7 – D5 from ISA Bus
8 – D4 from ISA Bus
9 – D3 from ISA Bus
10 – D2 from ISA Bus
11 – D1 from ISA Bus
12 – D0 from ISA Bus
13 – ???
14 – Pin 2 of the upper onboard C012
15 – ???
16 – Pin 1 of the upper onboard C012
17 – ISA Pin B8 (NoWS)
18 – Pin 2 of the lower onboard C012
19 – ???
20 – Pin 1 of the lower onboard C012
21 – MEMW to ISA
22 – MEMR to ISA
23 – ???
24 – ???
25 – VCC
26 – GND

From these findings I conclude that J2 is directly connected to the upper onboard C012 while J1 is either connected to the lower onboard C012 (J3 & 4 set to upper pins) or to the C012 on the LINK DR (J3 & 4 set to lower pins) which has its data-lines connected to the ISA bus.

On the main-card are 3 other jumpers:

  • J1 & J2 – Set the connection speed of the two C012 on the card
  • J3 – Select the ISA IRQ. Top down: IRQ 10, 11, 12, 15.

Everything else I have for now is a single article from the German computer magazine “c’t” (3/91,p.164 by O. Grau and A. Stiller) giving a bit more insight in the way the card works:

“Das Interface zum ISA-Bus des Hostrechners ist auf einer kleinen austauschbaren Platine untergebracht und basiert auf einem FIFO. Durch ihn geht sämtlicher I/O. Ein vergleichsweise aufwendiges Protokoll sorgt für einen recht langsamen Datentransfer, so besteht jeder Transfer aus dem Kennbyte 0 (Schreiben) oder 1 (Lesen), gefolgt von der Zieladresse (vier Bytes) und dem Datum (vier Bytes).”

The interface to the hosts ISA-bus is located on a small changeable board and is based on a FIFO [buffer]. All I/O is going through this. A comparably complex protocol is the reason for the data transfer being a bit slow. Each transfer consists of a ID-byte (0=write, 1=read) followed by the target address (four bytes) and the data (four bytes).

This “protocol” sounds very familiar to me. INMOS had the same, calling it PEEK and POKE… I’m still evaluating this, so stay tuned.

[11/05/10] Great News! I had some time and did some deeper investigation… hardware archaeology at its best 😉 So read on in the next post… it’s dissection time!