Archive for the ‘Uncategorized’ Category

Entex MAC

March 4, 2023

In this blog I try to talk only about computers with the understanding that computers are devices a user can execute programs on that haven’t been contained on this computer before (I am aware that this definition of a computer helps only to distinguish between, let’s say, dedicated word processors and computers in our sense. Using this definition, an Amstrad PCW is a computer, a Magnavox VideoWriter is not).

But there are some devices that stretch that definition, I must admit. One of these devices is the very cool, but barely-a-computer Entex M.A.C. that I want to explore in this post.

Entex Industries was an US-American toy and electronic game manufacturer that existed from 1970 to the early 1980s. Their toy lineup included a Lego-like system called Loc Blocks and model kits. As its high times it wasn’t a too small company either with sales exceeding $100 million in 1980. The “Entex” company name derived from NTX, which were the initials of two of the company’s founders. The company logo was an Royal Air Force bullseye with a smiling face overlayed on it.

The electronic games Entex produced (mainly handheld and tabletop electronic games, often mimicking arcade games) were adressed at the more high-end market. The three highlight products for me from these products are the Bike Computer (not a game, but indeed a computer for your bike if you don’t mind to have a medium sized tabletop calculator sized thing on your bike handle), the Adventure Vision tabletop console (exceedingly rare, especially in working condition), and the “Multi-functional Advanced Computer” or MAC Mini Computer (and no, Apple could not sue them, Entex had this name much earlier and was probably bust anyway by the time the Macintosh came around).

The package promises “The First Fun Home Computer for Kids and Adults with Game, Music, Math and Programming Capability”. It reveals a slick, red plastic device with a calculator-like keyboard, a display with a 4×4 (full-size) LED matrix, and a (VFD) 8-digital numeric display beyond. The right side of the case contains a series of small black cards with holes and some description on it.

But before we dive into the software aspects, let’s look at what makes this device interesting to me: the use of 2 4-bit chips of the family of the world’s first microcontrollers: The Texas Instruments 1000 series. This series of 4-bit chips were first used in 1972, being beaten by Intel’s 4004 CPU chips by only a short time (the 4004s were no microcontrollers, but required quite a number of chips for a complete system). The 1000 series was first used in TI’s own calculators before they were sold to everyone from 1974 on. The 1000 series contained ROM, RAM, counters, timers, and I/O interfaces and was used in a plethora of toys and calculators.

The 1000 series models Entex used in the MAC was one TMS 1600 with 4000 bytes of ROM, and 64 bytes of RAM (yes, bytes, not kilobytes), and a TMS 1170 with 2000 bytes of ROM, and another 64 bytes of RAM, and the interface to run a VFD display (therefore, the 1600 in the MAC dealt with making music and the programming, and the 1170 did the calculator and the games). The ROMs are mask-programmed, this means that the ROM content is added during manufacturing of the chips and cannot be changed later on. This makes for smaller production cost, but also maximum inflexibility, because if you want to change the software in the ROMS, you have to produce new controller chips. For good measure the two microcontrollers are complemented by a TMS 1024 “Interface Expander” that deals with addressing the 4×4 LED matrix.

Let’s now look at what the MAC came with and what it could do.

The Manual

Normally, we do not talk much about manuals because they either state the obvious or are, in the best case, boring but useful references. For a toy, the expectations are normally even lower.

However, this isn’t a suspicious leaflet by an Asian manufacturer translated by the half-blind daughter of someone who used other Asians manuals to learn English, but a very decent 50-page (at least in German) brochure by a knowledgeable expert in the field, probably the engineer who designed the entire device. Therefore, the MAC manual surprises with accurate, detailed information, giving the big picture of how computers change the world (at the time), and concrete assistance for the user. This is partly really needed because there is so much non-obvious functionality, and partly it is way more information the user really needs because he/she cannot use it anyway.

The “punch cards”

As I wrote above, the MAC comes with a series of black cards that ressemble a little bit computer punch cards, and one asks oneself how the MAC reads these holes. The disappointing answer is, it doesn’t. The cards can be inserted in a slot on the top of the display in order to hide some of the LEDs for some applications. If you play the Tic-Tac-Toe game for example, it reduces the 4×4 matrix to the 3×3 one needed for the game and for some applications it also adds some inscriptions to the LEDs so you know which button to press to address this LED position.

The Calculator Mode

The calculator is a very basic run-of-the-mill 4 species calculator with one memory slot and 8 digits (my machine displays 00000000 when the number overflows, this seems strange to me). Together with the VFD display and the calculator keyboard, this functionality feels very much like the spritual home of the hardware. 10 of the 50 pages of the manual explain the calculator using many examples.

The “Music” Mode (a.k.a Beep Machine)

You have two modes for making music (or noise): piano and organ. The tone does not differ in both modes, the only difference is that in organ mode the tone is held as long as you press a key. You can either play “live” or record and play back songs. You have two octaves of tones, but you can play only monophonically. In record mode you can also access the half tones. In this mode you can even vary the length of tones and add pauses of different length. I don’t know much about music, but what I know is that the tones are played VERY LOUDLY.

The Games and Applications

There are 5 games and applications contained in the MAC. There is a 2-player Tic-Tac-Toe game where (inexplicably) the users have to decide themselves whether someone won the game, a game called Tactics that I do not really understand, a game called Concentration that I do not really understand, a tool that can calculate the local time in a number of cities given an entered time and time zone code, and finally some sort of slot machine (which I do not really understand). All in all, nothing exciting.

Programming Mode

The other thing that really interested me was the programming mode. You can have up to 55 commands and the P1 key starts a program and halts it (and then you can re-start it again by P1). When a program reaches the end, it simply starts over again. I was really baffled though when I learned the commands. You have commands to play tones, to switch on the LEDs for an amount of time, and to switch off all lights. That’s it. That’s not exciting at all. Err, wait, and then there is an example program in the manual that gives you a digital die. How can you program a random die with only these commands??

This is the place where you could try to figure it out yourself. I have given you all the information you need to know. It took me a while to understand it.

Ready? Ok, the randomness comes from the user, i.e. the point in the program execution when he or she presses P1. The program consists simply of the sequence of all numbers on the die that are displayed on the LEDs one after another, and the one that you roll is the one that is currently displayed when you press P1. As the computer runs through the program so fast you can neither distinguish the numbers on the LED matrix nor react fast enough, you cannot control which number the program stops in. Genius!

Of course the lack of any flow control commands means that all your programs have to fit into this scheme or they are programs that need to be always the same. You have a metronome program as an example and you can play melodies or have pretty patterns using the LEDs.


Some of the Entex electronic products were also available under different names in some countries. The MAC was also sold under the name “Multifunktions-Spiel-Computer” by the giant German mailorder company “Quelle” (their main catalog was over a 1000 pages and was printed in 8 million copies). This Quelle version might have been sold the most because nowadays this is the version that seems to be available more often.

I have the Quelle version, which means a (sometimes not very knowledgable) translated German manual and German cards (and because the German card descriptions would need more space, most of the cards instead just refer to the corresponding manual page).

The battery compartment of my MAC is so mucky that I did not want to clean it. Therefore, I can report that the MAC runs just fine on a 6V universal power supply with a 2.5mm plug (plus on the outside, minus on the inside). The MAC package says the device needs 250 mA.

When opening the MAC and looking at the PCB (and you need to unscrew basically everything for that, undoing some 15 screws, including two tiny ones holding the on/off siwtch), I found that two of the TI chips have Japanese-style markings on them indicating that maybe at least the PCB was soldered in Japan (see Photo).

Also, as expected by the use of the microcontrollers, there is not much else going on on the PCB component-wise, some resistors and capacitors, a few transistors, the three chips, the LCD, the VFD, and that’s it. This is, of course, very appropriate for a toy.


The Entex MAC is an early toy computer with interesting hardware and an attractive esthetics. It has an unexpectedly good manual, but is limited in its capabilities due to the restrictions of what could be delivered at the time in a toy. It cost $80 in 1981 at a time when e.g. a 16kB 8080A-based Interact “R” home computer was advertised for $249 (because the remaining inventory of the closed original manufacturer was sold off).

From a collector’s point of view the Entex MAC is a relatively rare thing, but maybe not many people want to have one because it falls a little bit in the void between a game and a computer.

Technical Data

1 TMS 1600 N2LL Microcontroller
1 TMS 1170 NLHL Microcontroller
1 TMS 1024 NLL Input/Output Expander
with together 6000 Bytes Masked-Programmed ROM
and 128 Bytes RAM
4×4 red LEDs
8-digit VFD numeric display
27-key keyboard
Uses 4 C batteries or a 6V, 250 mA power supply with a 2.5 mm plug, plus on the inside
Initial price: $80 ($260 in today’s money)


IPC MagicWriter

December 29, 2021

Recently, I had the rare joy to open the still sealed box of a PDA computer. Normally, one would think twice about opening a still sealed box, but this is a model that is so rare that there is almost no demand for it. I got it for 20€, postage included.

The manufacturer’s name on the box is IPC, a very well-known (in fact, the largest) Singapore computer manufacturer at its day. During the Asian financial crisis at the end of the 1990s its computer ventures dwindled and IPC nowadays is into property investing.

The model name is the “MagicWriter”. Does not ring a bell? Don’t worry, it did neither for me nor probably for any other person outside the handful of people that were involved in its development.

So, what is the IPC MagicWriter?

As I mentioned, the MagicWriter is a PDA or Personal Digital Assistant, a moniker for a relatively small, light-weight pen-based mobile computer (typically without keyboard) that usually included applications such as a notebook, an address book, a calendar, and the like. One can distinguish between a dedicated PDA which can exclusively execute the contained applications and a PDA computer, which also offers a built-in programming language or at least some way to execute programs that can be loaded into the computer. Unfortunately, the MagicWriter seems to be a dedicated PDA (because I like the computer variety more).

The MagicWriter was sold from 1994 or 1995. It was designed by a Singapore company, Imagique Computer Design Pte Ltd. It was manufactured by IPC. I read a rumor that can be read that 10,000 devices were sold for deaf and mute people in Japan, but I cannot confirm that.

Another source mentions that Com 1 (French company) designed a PCMCIA GSM/telephone/fax card (maybe also the software?) for the MagicWriter, and a corresponding hint to the existence of such a card can be found also in the manual.

The MagicWriter came with some applications bundled with it: a File Explorer, a Database, a Spreadsheet/Calculator, a Calendar, a Schedule, a Memo, and a Phonebook/Address Book. You could also search in the data. Due to its nature of being a pen-based PDA without a keyboard, the MagicWriter has some basic handwriting recognition in the sense that you can enter single characters in some pre-defined boxes when input is required. A virtual keyboard could also be used.

Quite a mystery for me is the Operating System of the MagicWriter. As we will see later on, the PDA is basically a mobile PC hardware-wise. It has a PC chipset, a (Phoenix) BIOS, 1 MB of RAM and 2 MB of (Flash) mass memory. Still, neither the package nor the manual (or any other source for that matter) mentions an Operating System, PC-wise or otherwise. There is also no GUI on the screen, just a sea of text. The functionality of a dedicated PDA also does not require an explicit Operating System, and the PC BIOS supplies already a base layer of I/O and other functions. Maybe the applications directly sit on the BIOS.

The sealed MagicWriter package contained:

  • the PDA itself
  • 3 AA batteries (partially spilled out, but as they were still sealed separately, no harm was done)
  • a (dumb) pen
  • a faux leather 6-hole ring binder with some paper in it where the PDA could fit in
  • a PC 3.5″ floppy disk titled “Windows Application”
  • a 40-page, loose-leaf manual to be inserted into the ring binder (but without holes)

Now, let’s have a look on the inside of the MagicWriter:


The PCB seems to be quite clean at first, but after a closer look one can find a major revision done to it (using even an own small PCB, hand-connected to the major PCB components). This seems to indicate that a) there was a major problem to the PCB revision and b) that the device was priced high enough that just tossing the original device into the bin was not an option.

The used CPU is a 1994 Chips & Technologies F8680A SoC which unites the CPU, RAM management, power management, and CGA video. It is said to be 80286 compatible through emulation on the chip which is a enhanced 80186 clone. It runs on 14 MHz. It was used in all sorts of subnotebook and embedded computers. There is also a predecessor, the 1991 8680 running on 10 MHz. It was used in the 1992 Gateway 2000 “HandBook” DOS (but not Windows) subnotebook.

Major chips found on the PCB

  • C&T F8680A (CPU SoC)
  • C&T F87000 (Multi-Mode Peripherial Chip, handles PCMCIA cards) x2
  • Toshiba TC518512FTL-80LV (PSRAM) x2
  • UM62256DM-70LL (128kB SRAM)
  • Intel E28F008SA-120 (1 MB Flash) x2, one having a
    • PhoenixPICO BIOS PRODUCT and one having a
    • Phoenix PCM+ sticker

As I said, the box was in the original shrink wrap, and the content of the box clearly never taken out. Still, when took the PDA out, there were some loose screws rattling in it (which I tossed out before switching it on). Unfortunatly, I could not convince the thing to switch on, neither by using batteries, nor by attaching a power supply to it. I did not find any popped condensators nor batteries inside, so either the thing did never work, or it deteriorated in an silent way over time.

Why was the MagicWriter not succesful? We do not know the initial price or whether there was a major flaw preventing the usage of this device, but let’s assume it did work and that the price was not too high. What chance would such a device have had in 1995? Large, tablet-sized pen computers in numbers existed since 1991 (NCR 3125). They were heavy, and they were pricey, and they were something for the professional user. In 1993 some mid-sized and quite portable pen-based machines were released: the Apple Newton, and the Tandy Z-PDA. The Newton promises recognition of cursive handwriting, but basically falls short of this promise with the first models. In 1994 General Magic and its conglomerate of Sony, Motorola, and other heavy-weights give the PDA idea a new twist by putting the focus on communication, allowing some of their devices to even communicate wirelessly. All these devices have some sort of GUI, the General Magic devices even a very graphic one. From 1996 USR will revolutionize the PDA market by making the devices cheap, very lightweight and small. Pocket-sized DOS PCs (even if the did not have a pen) exist since the Atari Portfolio in 1989. So, in 1995 bringing out a text-based PDA that is not even DOS-compatible seems like a recipe for failure (and it probably was).

From a collector’s point of view, dedicated PDAs are not very interesting, and there are many makes. This model, however is at least very rare (my MagicWriter seems to have the serial number 461), and it uses a quite rare, interesting chip set. The Operating System is a mystery. Maybe there is a way to execute an arbitrary program.

Technical Data

CPU: Chips&Technologies F8680A@14MHz (80286-compatible)
Mass Memory: 2 MB Flash
OS: unknown
Interfaces: 2 x PCMCIA type II slots, RS232 (proprietary connector)
Batteries: 3 x AA Alkaline
Size: 210x135mm
Weight: 455g
Released in: 1995
Number of produced machines: unknown
Initial price: unknown


Gepard – Part 8: The 3rd life of the Gepard

May 23, 2020

Somewhat unexpectedly another person contacted me and told the story of the 3rd life of the Gepard. This person is Hans Carlos Hofmann. I already read his name before as it appears in copyright notices of some of the later versions of GDOS. As it turns out, he can shed some interesting light on the history of the Gepard after the phases I explained earlier. So, in the following, please find his information (translated from German by me). In the following, “I” means Hans Carlos Hofmann.

I received at that time the source code of the compiler from Mr. Müller as well as license to distribute it as a binary for computers of the Gepard architecture. The reason for that was that modifications of the compiler were needed in order to support MMUs (for the Motorola 68030) and FPUs (for the 68020 and 68030).

I, together with another student, then also developed GDOS further as I had a need for computational power. This other student was Harald Hellmann who developed the data processing for the measuring system for the ion drive at the University in Gießen.

I then used the finished system for my theses in Math and Physics so the system was also represented in the “Experimental Physics II” department (Ion drives were and are a topic in the Experimental Physics I department, translator’s note). At that time I validated a program written by Martin Berz, today a professor (at MSU, translator’s note) that calculated ion optics. The validation took place by comparing the results from his program with the ones from my independant implementation in Modula 2. Thanks to Modula, my implementation was more readable, but could not be run on a CRAY. I’m still a little bit proud in that the most errors could be found in his implementation.

The improved operating system that we called “OS/Science” (you will see in a moment why) received many, partially spectacular modules.

The first module was the interrupt handler. The original Gepards did not do interrupt handling, all the PCBs had was a simple jumper to order the CPU to get an auto vector. A program had to handle interrupts itself. If a program exited, e.g. due to an exception, an active interrupt jumped into nowhere, and you had to reboot the computer. All these problems were solved by my interrupt handler by dynamically creating machine code for the current situation. Using this handler, all the drivers were updated, one by one, so no polling was necessary anymore. This ended up that later applications could stand up to 3000 interrupts per second.

Exploiting this ability a “virtual processor” module (nowadays these would be called threads) was developed that ended up in a preemptive multitasking scheduler offering cooperative multi-user management. The latter features was added due to Modula-2 because else the compiler would have needed modification.

After the Gepard Computer company had ceased to exist, not only HS Computer built Gepard clones, but also the MediSyst company of Prof. Dr. Dimpfel (which existed until September 2005, translator’s note).

With my metrological applications I helped a lot of people to get their PhD, enabling quite spectacular presentations like these ones:

The technology of representing data by dynamically generated code was then used in other modules and applications. One of these applications was a Raytracing program from the begin of the 1990s. It computed an entire day for a single picture and heavily swapping data in and out using the MMU as there was 20 times more memory needed as existed physically. Here are some examples of the generated graphics:

Info Graphics
Visualisation of Atomic Force Microscopy

The “Gepards” were then built until the beginning of the 2000s. New cards were added, e.g. better graphic cards. One Atari (ST)-compatible graphics card could be used both for text and graphics, one that could switch between 1 byte color for every pixel and having 8 different, monochrome pixel layers, and one based on an Intel GDP chip that could execute graphics command in hardware. One big strength of the system was that, already in the 1990s, I could use up to four displays with realtime graphics.

Other things added were a SCSI subsystem for hard disks, tapes, floppy disk drives, optical drives, ZIP drives, CD and DVD drives, photo typesetters, a relational DB, a video subsystem, and a NFS V2 server.

Unfortunately, there was no new CPU/memory board among the new things. HS Computer did develop a Motorola 68040 prototype card, but the design turned out to be unusable due to problems that could not be solved in software. In a system like the Gepard where the bulk of the software is compiled by the onboard compiler, there is this chance to compensate for hardware bugs by centrally providing suitable code generation. The same problems occurred when a 68060 prototype was tried out. MediSyst wanted even to develop a 3 x 68030 + memory card but failed out of economic reasons.

The successor company of MediSyst, MEWICON CATEEM-Tec had the last generation of Gepard-like computers in production until early May of 2020(!). Due to the economic consequences of the Corona virus the now 75-year-old owner of MEWICON (and MediSyst), Prof. Dimpfel has now decided to close his company. Therefore, only a few weeks ago I had the honor to switch off the probably last of the Gepards in production – after over 30 years of Gepards still being used at the one or the other location.

BURP – Basic Using Reverse Polish

March 21, 2020

Recently, I did not buy a new old computer. I did not buy it because I was outbid in a real auction in the UK (by twice the amount I was ready to pay, not to mention the 33% fee on that price for the auction house and the VAT, nor the additional cost to package and ship the whole thing). However, I am very ok with not having bought it, because it would have been a kit computer of unknown state, there wasn’t any documentation with it, and it featured only a Z80 CPU. The only three redeeming qualities of this model are its rarity, its use of a mathematical co-processor, and its unusual programming language. So, I decided to proceed as if I had bought the computer, and write about the programming language.


The computer was a Powertran PSI COMP 80 computer (sold for 420 GBP + commission). It is a relatively early (1979) design published by the British magazine Wireless World and used as a basis for a singleboard computer sold as a kit by a British company called Powertran. Z80 CPU, 8 kB of RAM and EPROM, 2 kB of video RAM, monochrome graphics of 128×64 pixels or 64×32 characters: not an usual design for that time. What made this model a little bit special was the use of a mathematical co-processor, a National Semiconductor MM57109N.

But let’s start at the programming language of this computer. It is called BURP, “BASIC Using Reverse Polish”. The reverse polish notation is the thing where you first specify the parameters of a function (which are pushed on a stack), and then you specify the function name. When the function is called, it takes its parameter from the stack, calculates the result, and pushes it back on the stack. This is the (still quite exotic) basic principle in Forth, some early HP pocket calculators, and Postscript. So, if you would write something like add(10,33) in any conventional programming language (requiring a parser to translate this code into something a computer understand), in reverse polish notation that would become “10 33 add” with the semantics “put a 10 on the stack, then a 33, then call the add function, who will take the two parameters from the stack and put the result (43) back on the stack for the next function to use”. This notation allows for quite compact interpreters, but the programmer has to manage the stack herself.

I like Forth a lot so I thought, ok, this is funny, a BASIC with a reverse polish notation should be quite quirky, ending up in programs like ’10 “Hello, World” print 20 10 goto’ if this type of basic also supports line numbers. However, BURP is even more strange than that because not all commands use the reverse polish notation, but only expressions. The rest of the syntax is still conventional infix notation.

All this strangeness has a reason: the mathematical co-processor. As [Carver] puts it, “The constraints of the MM57109, which was essentially a dedicated calculator chip with a 4-bit microcontroller interface bus, strongly affected the design of the language. Significant features of the language include a fixed set of 26 numeric variables (A-Z), a maximum of 256 lines of code, a three-deep hardware stack for expressions, a limit of one for-loop at a time (so no nesting, not even in GOSUBs) and no string processing (except implicit concatenation of static text and numbers during output.)” Oh yes, plus the MM57109 talks to the world in reverse polish notation.

Ok, so the number calculating part of this BASIC by and large represents the format which the math processor needs. So, how does a BURP program looks like?

Example: LET C = 3 SQ 4 SQ + ROOT

Here, we assign a value to a variable C. This value is SQRT(3^2 + 4^2). First, the 3 is put on the stack. Then, a “squared” operation is called on the 3, replacing it by 9. Then, the 4 is put on the stack, and then replaced by 16. Now, and add function adds the 16 and the 9, replacing it by 25. Finally, the square root is taken, so in the end, the only number of the stack is 5, which is assigned then to the variable C (actually put in register C of the math chip).

The National Semiconductor MM57109 (the original data sheet titles it as a “Number Cruncher Unit”) is from 1977. It is the mask-programmed derivate of the MM5799 chip, which is the 2-chips-in-1-version of the 5781/2 chip set, the calculator chip family of National Semiconductor. It added 70 mathematical functions to the MM5799 design. From the viewpoint of a computer manufacturer, this is very attractive, because a) you don’t have to write all this math code yourself, b) it is efficiently executed. However, the MM57109 was not really an FPU (floating point unit) like modern math co-processors (which are nowadays integrated into the CPUs). First, the unit processed numbers that came in up-to-8 decimal digit packets (coded as 4-bit BCDs). Second, “Instruction execution times range from 1 ms to 1 second” (according to the data sheet). ONE second. That makes total sense for a calculator, but not too much sense for a computer. However, “real” FPUs did not exist much before 1977, with AMD’s AM9511 being one of the first.

So, here you have it. An early kit computer with a calculator chip as a mathematical co-processor and a crazy BASIC that makes complete sense in this design. Burp. Happy digesting.


Unusual Sony Notebook Drive Bay Modules

February 29, 2020

It is not completely unheard of to have a modular bay system for notebook computers, having the possibility for the user to chose whether to have an optical drive there, or maybe an additional battery, or the like.

But I think that there was a decision meeting missing after a brainstorming session at a Sony computer department when they came up with these additional bay modules:

PCGA-CWN1 Compact Woofer

Yes, this is a woofer. It works because it seems that the bays were open at the bottom:


PCGA-TKN1 Number Pad

Yes, it is exactly what you think it is – an additional number pad you can flip out of the bay:


And, no, these were actual products, no photoshopped fakes.

Not crazy, but also quite unusual is this bay module:

PCGA-MDN1 Net MD drive

Yes, that’s a MiniDisc drive for a notebook.


Western Digital Pascal MicroEngine, an Update

February 16, 2020

Yesterday, I received a 2nd MicroEngine board, unfortunately in a worse state than my first one. Also, probably an earlier patch level as there is less patch cableing on the board. Nevertheless, nice to have.

Also, if you look for images for boot floppy disks, you can find them under

VGA explained Hands On

July 13, 2019

If you are like me you do not know much about hardware. In case you wonder how all this (old school) video interface is working, say in case of VGA for example, you are in luck. In this video (and its part II) a Youtube channel called Ben Eater explains the basic VGA signal by freaking building a simple graphics card using breadboards and simple circuitry. He does this, layer by layer, in order to fulfill the different aspects of the VGA specification. And afterwards even I have the impression to have understood how the thing basically works.

The (arguably) most pleasing Floppy Disk Drive

February 24, 2019


I saw recently in an Ebay auction the most pleasing floppy disk drive subsystem ever. Ever! Unfortunately it was too expensive to buy just as a conversation piece.

I am not sure what the designer usually did. Maybe tape drives? Hifi devices? Mainframe peripherals?

Also, seems to be a very rare thing. Google knows nothing about a SORD FD Processor A73…

Once upon a time

April 29, 2018


I recently ordered audio cassettes and a DIN audio cable as new products… I take “Things that belong in the last century” for 100. #thingsourkidsdontknow #longtailproducts

Plan Informatique Pour Tous (IPT)

December 28, 2017

Apart from my exhibition on Micronique computers, at the Classic Computing 2015 in Thionville, France, I also had some slides on a French programme to introduce computing to more schools in the 80s called “Plan Informatique Pour Tous (IPT)” or, translated to English, Computer Science For All. Because of its importance in France and the notoriously rare availability of any information on old French computers in English, here they are.

Plan Informatique Pour Tous (IPT)

  • was a program by the French government to:
    • introduce the 11M French pupils to computer science
    • support the French computer industry
  • its targets were presented on 25.1.1985 by the Prime Minister:
    • put 120k computers in 50k schools
    • train 110k teachers in computer science
  • the budget of IPT was FF 1800M in total, FF 1500M of that for hardware, i.e.:
    • FF 15k for every computer system
    • FF 2700 for every teacher
  • the high-flying goals of the program were not reached; on the other hand this program exposed many pupils to computers for the first time
  • the selection of industrial partners was given to Gilbert Trigano, co-founder of the Club Méditerranée
  • originally, he intended to give the order to Apple buying specially modified Macintoshs
  • the intended agreement would have meant that instead of in Ireland, Apple would have located the European Macintosh factory in France and transferred state of the art assembly knowledge
  • instead, out of political reasons, only French manufacturers were invited
  • out of the same reasons, the finally selected partner was Thomson, a nationalized enterprise in financial troubles

And here you have all the contenders to the IPT competition (that I know of) and how they did in the competition:


The winners were Thomson with their MO5s and TO7/70s. To a much smaller degree, also exelvision could sell some of their EXL100s.

Le nanoréseau (The Nano Network)

The IPT proposal was heavily centered around a proprietary network technology called “Le nanoreseau” that was developed prior to the competion by the Lille University of Science and Technology.

  • The Nano Network
    • a 500 kbps (RS-486-based) network connected:
    • 1 PC-compatible server (called network head) with two 5.25” floppy disk drives, 512 kB RAM, and a printer (Mannesmann-Tally MT80)
    • up to 31 Thomson (8 bit) microcomputers (called nano machines)
  • the network allowed to:
    • load programs and data onto the microcomputers
    • communicate between all computers
    • exchange screens between the computers
    • execute a program on the computers
    • use the printer at the server from all computers
  • in principle the approach was working very well, but using 8-bit machines as terminals was old-school already then