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)



The Fujitsu Micro 8 and its Bubble Memory Drive

January 7, 2022
Fujitsu Micro 8

At the VCFB 2021 in Berlin I presented a recent purchase of mine, a Fujitsu Micro 8 computer complete with its Bubble Memory drive option.

If you do not want to the read following post, you can simply watch the video.

Ok, so obviously, you want to read about it. Here we go!

Let’s start with the manufacturer. Fujitsu is is a Japanese multinational information and communications technology equipment and services corporation which was established on June 20, 1935. This makes it one of the oldest operating IT companies after IBM and before HP. Fujitsu manufactured in 1954 Japan’s first computer, the FACOM 100 mainframe, and launched in 1961 its second generation computers (transistorized), the FACOM 222 mainframe. Fujitsu was a major chip manufacturer until 2014 when they spun off their chip manufacturing business. Think of it as a Japanese IBM if you do not know the Japanese market.

At the beginning of the 1980s, personal computers become a hot topic, and Fujitsu decides to enter this market (at this stage they (as other Japanese manufacturers) have alread released their first micro computer, the LKIT-8 kit). In contrast to IBM, Fujitsu wants their first real entry to the personal computer market to be at the very front of the state of the art. Also, they aim both at private owners and at small businesses. So, the list of features of this model, the Fujitsu Micro 8, released in May of 1981 is very impressive:

  • 2 x 6809 CPUs (one Fujitsu 68A09 processor at 1.2 Mhz as the main CPU and one Motorola 6809 @ 1 Mhz as the graphics processor)
  • 64 kB RAM (first usage of 64 kbit DRAM chips in a microcomputer)
  • 48 kB VRAM
  • 44 kB ROM
  • 2 x Bubble Memory drive as an option (first such drive in a microcomputer)
  • graphics with maximally 640×200 pixels in 8 colors
  • many interfaces: cassette, digital RGB, Composite, TV, cartridge, expansion, RS232, printer, analog in

Unfortunately, this list of features does not only wow the consumer, it also makes him/her notably poorer as it requires Fujitsu to ask for a price for the basic model of 218 kYen then which is about 290 kYen today which corresponds to $1982 or 1690 EUR today. This price does not include the many available options as we will see below.

Internal Options:

MB22003 Kanji ROM (2965 JIS Level 1 Kanjis), 16×16 pixel 30‘000 Yen
MB22002 Non-Kanji (figures, symbols) ROM 10‘000 Yen
MB22401 Z80 card 11‘700 Yen
MB28011 8088 card (set with CP/M-86)
MB22601 Bubble holder unit 85‘700 Yen
FBM43CP Bubble cassette (32KB) 35‘000 Yen

External Options:

MB27603 Standard floppy disk drive (8 “)
MB27605 / MB27607 Mini Floppy Disk Drive (5.25 “)
MB27606 / MB27608 Thin mini floppy disk drive for expansion (5.25 “)
MB22605 128KB Bubble Holder Unit
MB27301 12 inch high resolution color CRT 188‘000 Yen
MB26001 System Expansion Unit
MB22603 FDD interface Card 17‘000 Yen
MB27601 5 inch FDD 313‘000 Yen

Operating Systems Options:

SM07217-F023 F-BASIC Ver. 2.0 (So-called DISK BASIC, but it works in RAM without using the main ROM)
SM07217-F061 F-BASIC Ver. 2.2 (128KB bubble cassette)
SM07217-M041 OS-9 / 6809 Level 1
SM07217-M021 FLEX
SM07217-M033 UCSD Pascal
SM07217-M011 CP/M-80 (with Z80 card installed)
CP/M-86 (when 8088 card is installed)

One option we might have to explain non-Japanese readers is the “Kanji ROM” option. What is it and why was it so expensive?

You have to understand that written Japanese consists out of three different character sets. Two of them, Hiragana, and Katakana use relatively simple signs and consists of about only 50 characters each. They can be represented easily using a “normal” 8×8 pixel grid, and they do not require much more memory than Latin characters (also, they do not have upper and lower case). The problem is the third character set, the Kanjis. These are basically Chinese characters (in principle, the reality is more complicated). These are both graphically complex and there are many. They are so complex that a normal 8×8 grid cannot be used because you could not see the differences between the characters. There are also so many that they do not fit into a standard amount of ROM. Therefore, the Kanji option switches the character grid to 16×16 pixels (and quarters the amount of characters on screen), and it provides enough ROM space for the additional almost 3000 different(!) characters. To that end it is delivered in 128 kB consisting of 16(!) additional ROMs for which there are also sockets on the PCB.

My Micro 8 came with the Bubble Memory drive option, the internal Z80 card and the Kanji option. It likes to throw its 1.5A fuse when it gets more than 100V, e.g. 110V…

Let us conclude the view on the core model with a note on its two CPUs. It sounds very promising to have a computer model with two of these components. Does this make the machine twice as fast? Well, no. See, as I mentioned, the 2nd CPU was the chip responsible for the graphics, and this model does not have another dedicated graphics chip. Also, it acts as a complete independent system. It has its own boot ROM, its own memory, and runs its own program. It communicates with the main CPU exclusively using a 128 byte memory area. So the main CPU writes into this shared area (while the graphics CPU is stopped), and afterwards the graphics CPU is re-started. This is not a very efficient way to communicate, and in the beginning it was almost impossible to write graphics intensive programs. Fortunately, one of Fujitsu’s BIOS programmers left several hidden commands in the BIOS. These commands permit to transfer large binary programs to a reserved memory space and JMP. Only after discovering this hacking technique, this model had enough graphics performance for fast games…

Now, the one option that makes the Micro 8 quite unique is the Bubble Memory drive (there are only two other (and later) computer models out there that use Bubble Memory as a standard). So what is Bubble Memory and why did you possibly never have heard about that?

Bubble Memory is a type of non-volatile computer memory that uses a thin film of a magnetic material to hold small magnetized areas, known as bubbles, each storing one bit of data. Non-volatile means it keeps its data even if the power is switched off, like e.g. Flash memory or a magnetic tape. Bubble memory started out as a promising technology in the 1970s, offering memory density of an order similar to hard drives but performance more comparable to core memory while lacking any moving parts. This led many to consider it a contender for a “universal memory” that could be used for all storage needs (i.e. main memory like RAM or mass memory like a hard drive).

Because of this appeal, by the mid-1970s, practically every large electronics company had teams working on bubble memory. Texas Instruments introduced the first commercial product that incorporated bubble memory in 1977. By the late 1970s several products were on the market, and Intel (later MemTech) released their own 1-megabit version, the 7110. Other companies that produced such chips were Sharp, Hitachi, Rockwell, and Fujitsu. This technology was even produced in the USSR.

In the first half of the 1980, companies offered Bubble Memory for computers, either as an option (here we have e.g. our Micro 8 in 1981, the “MPC BUBDISK” card for the Apple II in 1982 (128 kB for $895), or HP’s 9825A card in 1984 (128 kB for $1900)), or as built-in mass memory in portable computers (like the 1982 GRiD Compass or the 1983 Sharp PC-5000). Another use was Konami’s Bubble System arcade video game system, introduced in 1984. It featured interchangeable bubble memory cartridges on a 68000-based board.

Bubble Memory works as advertised, even if it requires a “warm-up” time before it can be used because it can be operated only if it is at least 30 °C warm. This initial warm-up time can be up to the 85 seconds the Konami system needed after a cold start (and this time “cold” is not meant figuratively).

So, why don’t we used Bubble Memory today? There are two main reasons. First, although Bubble Memory is as fast as core memory, it is much slower than (chip) RAM (which came later). Second, chip RAM and hard disks became cheaper than Bubble Memory quite soon. As a consequence, in 1981 major companies working on the technology closed their bubble memory operations.

Bubble Memory was used also after 1981 due to the only technical advantage it had left: it can store data even without power and it is immune to even severe movements because it does not have moving parts. It was the Flash memory of its day (Flash was not on the market before 1987) and was therefore used in mobile applications until the entire technology disappeared entirely by the late 1980s.

How does Bubble Memory work?

As I mentioned before, the bubbles, small magnetized areas exist on a thin film of magnetic material. This material is arranged to form a series of parallel tracks that the bubbles can move along under an external magnetic field. The bubbles are read by moving them to the edge of the material where they can be read by a conventional magnetic pickup, and then rewritten on the far edge to keep the memory cycling through the material. There is a very instructive animation(?) of such bubble moving through some material which can help imaging you this mechanism:

Taken from https://www.gsalmasi.com/newpage/bubbles.html

What does a Bubble Memory chip consist of?

Taken from a TI report entitled TIB0203 Magnetic-Bubble Memory and Associated Circuits from November 1978

See the above picture. First, you have the die with the magnetic area itself. It is wrapped in two layers of orthogonal coils. This package is sandwiched between two permanent magnets, and the entire package is housed in some tin case. For a real-life “unwrapping” of a Bubble Memory chip I can recommend Wolfgang Robels corresponding web page (http://www.wolfgangrobel.de/museum/bubble3.htm) which has a series of very nice photos.

Let’s come back to the Bubble Memory drive in the Micro 8.

Micro 8 Bubble Memory Drive

The optional Bubble Memory drive inside the Micro 8 has two slots and can therefore use up to two Fujtsu cartridges. These cartridges have a capacity of 32 kB each (later on, 128 kB cartridges were available, but I am not sure whether they can be used in this drive or only in the later, external drive). The cost of the option and the cartridges is enormous: the drive costs 85 kYen, the cartridges 35 kYen each. This made the configuration above cost 155 kYen (or $1400 today)…

As I said at the beginning, the Micro 8 was a very expensive model and it did not sell well. As a reaction, Fujitsu splits the Micro 8 only a year later into the FM-7 for the mass market at a much lower price (and without a Bubble Memory option) and the FM-11 which is aimed at businesses. The FM-7 becomes a very popular model in Japan and is of the “Popular 3” personal computers of that era.

From a collector point of view, currently you can buy Micro 8s at a not too high price in Japan, but one with the Bubble Memory option is very rare and is typically very pricey. In every case, they are quite cool machines.

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


Classic Computing 2021

November 21, 2021

My (as well as many others) first vintage computer event after the start of the pandemic was the Classic Computing 2021 in Vöhringen, Germany.

The exhibition took place in middle of September 2021, in retrospect one of the few periods in the last two years where there was both a relatively low Covid incidence rate among vaccinated people and where the pandemic restrictions where bearable and suited for such an event. The CC 2021 did have a 3G Corona protection concept (as required by the state of Bavaria) which was controlled at the entrance by an external person.

Due to the Corona concept, the area was not so densely populated with desks as in previous years and offered space for only some 30 exhibitors in the beautiful Cultural Center of Vöhringen. Also the number of visitors was smaller than in previous years (at 250 – 300 visitors), but still enough to ensure that the halls did not feel empty.

There were many interesting things on display, but my highlight was the Atari Museum booth of the local organizer who exhibited basically every Atari computer that there was.

I exhibited this year my Atari ATW 800 workstation, filling the only blank that the regular Atari exhibition left open 🙂 I originally wanted to work on installing the software so it would again, but did not find the time to do so. As a result, there was not much to admire that the hardware itself.

Many things were smaller this year, but one thing was was absolutely massive this time was the Take-away-for-free-corner. Using almost the entire length of one of the halls on the 1m deep windows board a plethora of consoles, games, software, computers, accessories, printers, and things of mysterious nature waited for exhibitors and visitors alike to be taken home and valued. It was so much that the entire area need to be filled a second time.

One tradition of this event which is the yearly convention of the German Association for the Preservation of Classical Computers (VzekC) is the auction. If there are hardware donations, they are auctioned of at one evening. Only members of the association can participate. As every year there is a good amount of interesting hardware and an equally large amount of not-so-interesting things to be auctioned off. In order not to have to scrap the uninteresting things ourselves, auction lots are bundled containing potentially interesting things together with uninteresting material. If you win an auction, it’s your task to take the entire lot with you. That’s why you find e.g. Sun workstations bundled with two trashworthy PCs. Everyone interested in a lot buys one or more raffle tickets and then the lot is raffled off. This event is always great fun, even if you don’t participate. This year we had e.g. a slough of Atari 2600 consoles together with a lot of cartridges, many Sun workstations, monitors, and many old PCs.

All in all, it was a worthwhile event that felt good after a long time without any face-2-face activities, and one hopes that Corona does not prevent such events next year.


(German) Youtube video. https://www.youtube.com/watch?v=7cBtx_KZrHw

My First Music – Picky Picnic: Cynical Hysteria World

November 1, 2021


This entry starts off our small OFF TOPIC series on Sony’s “my first Sony” products. It does not contain anything computer-related. It’s still vintage and collectable, though. This thing is even very rare…

If you are a global Consumer Electronics brand like Sony and you have a line of devices since 1987 aimed at children (which probably sells very nicely), you are always on the hunt for new products that you can sell to this specific target audience. Now, in 1988 you have bought the CBS Record Group for US$ 2 billion. Wouldn’t it be a good idea to sell a “my first music” (and “my first Sony”) line of records in 1989 to these customers so they can feed their “my first Sony” cassette or CD players?

Cynical Hysteria World

And that’s exactly what Sony did in Japan (only). They used the color scheme of “my first Sony” products (mainly red), slapped on a picture of a child holding a cassette player as well as the “my first Sony” logo on the package, and sold cassette and CD versions of these records (there were no record players in this line-up).

This all makes sense, and would only be a footnote in a book on the (hypothetical) Complete My First Sony Line-Up, stating that these products are very rare indeed.

Or at least it would be if not one of the releases (and, I have to admit, the only one I own, or could find any information about) would be a very strange one. Not indecent at all, just very very strange, given the age of the target audience and the assumption that probably the mass market was targeted.

Because the release that I recently bought is “Cynical Hysteria World” by “Picky Picnic”. Like you, I have never heard of this group or the record before. On the surface, the songs sound very child-appropriate, in the style of songs sung by a kindergarden choir.

In reality, though, Picky Picnic was an avantgarde, Japanese, New Wave band whose role model was the New German Wave, avantgarde band “Der Plan” (and which was, therefore, distributed in the beginning by the Der-Plan-label “Ata Tak”). Extremely niche.

The release itself is a 1989 re-release of the original 1986 EP. It consists of the cassette or CD and a A5-size color book(let) with the Japanese lyrics (see https://www.discogs.com/de/Picky-Picnic-Cynical-Hysteria-World/release/10667852/image/SW1hZ2U6Mjk3MzgzMzk= for pictures). The price was 1700 Yen. You can listen to the EP using the first link of the references below.

I have the feeling that all “my first music” releases are extremely rare. On the Internet I found a few informations (and pictures) on the CD version, but not on my cassette release.

I do not have the lyrics of the songs, but if I would have to guess, these would be completely harmless. So, from a music label perspective either a release decision by someone not really understanding the concept of the band, or by someone understanding it exactly and either giggling secretly for a long time or being cynical (or savy?) enough to monetize a record otherwise not commercially usable.

P.S.: I checked my favourite “my first Sony” reference picture, https://s.yimg.com/uu/api/res/1.2/FrpvqtlNwwewjcf97Gg6SA–~B/aD0yODY3O3c9NTQ3MjthcHBpZD15dGFjaHlvbg–/https://s.yimg.com/os/creatr-uploaded-images/2021-05/8ec17540-ae72-11eb-bcf7-7f7dd52b2a5d.cf.webp (because it contains many of these products in one image). On the left, you can see three “my first music” releases, none of them seems to be “Cynical Hysteria World”. But: the right most release seems to be the album cover of another Picky Picnic release, “Kuru Kuru World” (see https://www.discogs.com/de/Picky-Picnic-%E3%81%8F%E3%82%8B%E3%81%8F%E3%82%8B%E3%83%AF%E3%83%BC%E3%83%AB%E3%83%89-Kuru-Kuru-World/release/4847860) which is their 1990 LP. Wow, I want that!


Soundic/Hanimex Pencil II

May 2, 2021

When browsing through my boxes, I recently discovered that I had purchased (probably a long time ago) a very rare computer that is not well known and not very often described. This is because it probably was never widespread at any time nor technologically or price-wise attractive. It is called the “Pencil II” and was produced by a Hong Kong-based company called Soundic.

Soundic/Hanimex Pencil II

Soundic was a low-end electronic game consumer electronics manufacturer whose products, mainly pong-like games and games consoles in the 1970s and 80s were sold under a large variety of brand names.

In 1984 Soundic released their only homecomputer, the Pencil II (from what I can tell there was never a Pencil I). In true Soundic fashion, the Pencil II was also sold under the Hanimex brand, so that half the Internet pages call it the Hanimex Pencil II. Hanimex (Jack Hannes Import and Export) was an Australian trading company that imported cameras, Pong-like games and game consoles.

Let’s have a look on the computer.

The CPU is a Zilog Z80A (in a NEC version), the graphics chip a Texas Instruments TMS9929. It has a whopping 2k of user RAM and 16k of VRAM. The sound chip is a Texas Instruments SN76489A. The keyboard is of the chiclet rubber variety, much like a ZX Spectrum, even down to using a single-key Basic command input. The Basic comes as a separate cartridge. The machine has two joystick ports, a SCART output, a composite output, and a cassette interface. So far, so boring. The only interesting thing about the Pencil II is its possibility to run Colecovision cartridges using the optional Colecovision module.

I had a hard time understanding this computer model. It seemed to be an one-off for Soundic which never produced any other computer. It is not itself a re-labelled model of another manufacturer and seems not to be a clone of another model. It is clearly a game console at heart (joystick ports, small amount of RAM), but: what is it?

Slowly, a suspicion developed in my mind: maybe this machine is not a clone of another computer, but a clone of a games console. Using additional hardware it can execute ColecoVision cartridges, so does is it try a Colecovision clone?

And, if we compare the hardware, that’s exactly what it is. The 1982 Colecovision uses the same CPU, graphics chip, VRAM amount, and sound chip. It uses the same 2 joystick ports. The Pencil II has 2 kB of user RAM instead of 1 kB, but that does probably not cost more production-wise in 1983/1984.

So, if the Pencil II is a Colecovision clone, what is in the Colecovision cartridge? And, sure enough, it is only a ROM chip that probably contains a Colecovision-compatible BIOS that overlays the Pencil’s own BIOS. All the rest is already in the Pencil II.

Now, the Pencil II has a few more features than a Colecovision. Apart from the 2k instead of 1k of user RAM, it has a cassette interface, a proprietary printer interface, and the Basic (as a cartridge). It also has an additional interface to connect to Memory Packs housing more RAM (there is not much Basic program to have in 2k of RAM). Memory Packs came in 16 kB, and 64 kB. Using the expansion slot, the Pencil II could even connect to 5.25″ floppy disks via a controller module.

In this sense, the Pencil II is an extended Colecovision clone, between almost a Colecovision (because you still needed the Colecovision module) and Coleco’s Expansion Module #3 (the Adam expansion).

Bering able to use Colecovision modules, it is clear there was not a large need for games in the Pencil II mode. However, there seems to be 3 games that were sold by Soundic (at least in France):

  • PEN 701: Le Jardin Magique
  • PEN 702: Le plongeur a la recherche du tresor
  • Big Foot Chase
16 kB Memory Pack and SD-Basic 1.0

The Pencil II that I have does not bear the Hanimex logo, it seems to be a Soundic-branded model. Also, the Basic cartridge I have is a Version 1.0, whereas the Hanimex ones seems to have been delivered with a Version 2.0 Basic. BTW, the Soundic manuals and the Basic 1.0 have a copyright date from 1983. Probably, it was available in some markets already there.

Let’s have a look on dates and prices of the Pencil II in France. The Colecovision came out in April of 1983 for 1995 FF. The (Hanimex) Pencil II came out in November 1984 for a price of 2300 FF. I did not find a French price for the Expansion Module #3, but it must have been in the vicinity of the price of the Colecovision or higher (the US Adam price was more than thrice the price of the console).

It is not completely clear to me how many Pencil IIs were made in total or on which markets it was available. We know that the Hanimex version was sold in Australia and in France, but obviously, they were sold under the Soundic brand also elsewhere.

What we know is that a Pencil II nowadays is a very rare sight. And there you have it, the enhanced Colecovision clone: the Pencil II.

Technical Data

Manufacturer: Soundic (also sold as Hanimex)
Model: Pencil II
Date of Introduction: 1983, 1984
CPU: NEC D780C-1 (Z80A clone)@3.58 MHz
Graphics chip: Texas Instruments TMS9929(?)
Resolution: 256 x 192, 16 colors
Sound chip: Texas Instruments SN76489A
VRAM: 16 kB
RAM: 2 kB
ROM: 8 kB
Programming Language: SD-Basic (on cartridge, 12 kB ROMs)
Interfaces: expansion port, memory interface, printer, 2 * joystick, cassette, SCART, composite, PSU
Size: 37 x 22 x 7.5 cm
Weight: 1.5kg
Options: 16 kB RAM, 64 kB RAM, Colecovision option, floppy disk controller


Hitachi Basic Master Family

April 2, 2021

In the West, we often know astonishingly little about early Japanese computers, especially when they were not also sold in the Western world. One of these examples is the “Basic Master” family of 8-bit models produced by Hitachi from 1978 to 1985.

Being sold from 1978, the Hitachi Basic Master (MB6880) was the first real home computer in Japan (and the first one to use the term “personal computer” over there). Apart from early Western models (like the TRS-80) before the Basic Master, you could buy basically only single board systems like NEC’s TK-80. And as it was considered a niche household consumer device it was developed by the Yokohama-based TV Division, not Hitachi’s Computer Division (who did the “serious” computers).

Motorola 6800-based models

In contrast to most other home computers, the early Basic Master models used a Motorola 6800 CPU. The 6800 was Motorola’s first CPU, an 8-bit processor. Apart from the Hitachis, only the APF Imagination Machine used the 6800 (also the SWTPC 6800 and the MITS Altair 680 used this CPU, but these were not home computers in the classical sense).

The first model of the family is the Basic Master (Level 1), MB-6880.

Hitachi MB-6880

It has a Hitachi version of the Motorola 6800 CPU running at a whopping 750 kHz. It features 4 kB of RAM and 8 kB of ROM containing Hitachis Level 1 Basic that offers only integers. It can display 32 x 24 characters in black and white and offers a 64 x 48 pixel resolution. The video output is either composite oder (Japan) NTSC. The only mass memory option is a 300 bps cassette interface. This model uses an external PSU. The initial price wass 188,000 Yen.

1979 the second model was released, the Basic Master Level 2, MB-6880L2.

Hitachi MB-6880L2

The only difference to its successor is double the amount of RAM (8 kB), double the amount of ROM (16 kB) containing Hitachi’s Level 2 Basic (hence the name), now also offering floating point numbers. Also the initial price is significantly higher (228,000 Yen).

The successor to the Basic Master Level 2 is the Basic Master Level 2 II in 1980 (MB-6881).

Hitachi MB-6881

This time the RAM amount is increased to 16 kB and the price dropped to 148,000 Yen.

The final model that uses the Motorola 6800 is the Basic Master Jr. (MB-6885) that was released in 1981.

Hitachi MB-6885

It also offers 16 kB RAM, 16 kB ROM, and the Level 2 Basic. It is initially offered for 89,800 Yen and is considered to be an entry level model. In constrast to the other models described above it now has a dedicated VRAM allowing a resolution of 256×192 pixels monochrome, even if one cannot access it from Basic. The case now looks different and includes the PSU.

I recently bought this model and can now show you the inside:

Case opened
The PCB from above
The PCB in more detail

As one can see my model has the ROM upgrade which adds another 2 kB ROM and probably increases the cassette speed to 1200 bps. The PCB is very cleanly designed and built and contains a lot of Hitachi chips (that’s the advantage of being a big Japanese electronics company with a lot of experience in manufacturing consumer electronics).

The interfaces on the back of the case are labelled in Japanese. These are (from left to right):

  • Cassette
  • Video 2
  • Printer
  • Video 1
  • Expansion Port

Motorola 6809-based models

The models using the Motorola 6800 CPU were not the only branch of the Basic Master family. The first model of the other branch was released already in 1980. This branch used a Motorola 6809 8-bit processor which ran at 1 MHz. They used a completely different architecture than the 6800 models and featured a Microsoft Basic (called Level 3 Basic). Additionally, the 6809 models offered a resolution of 640×200 pixels or 320×400 pixels in 8 colors. The usage of Microsoft Basic and the graphics resolution modes influenced man other Japanese computer models at the time. Finally the case became much larger and offering 6 expansion slots, almost having an Apple II vibe.

The first model is the Basic Master Level 3 (MB-6890) (codename: Peach) released in 1980 and sold initially for 298,000 Yen.

Hitachi MB-6890

It offers 32 kB RAM and 24 kB ROM. It was also the first personal computer to offer Japanese characters! This model was also sold in Australia.

The successor was the Basic Master Level 3 Mark 2 (MB-6891) released in 1982. It was sold for 198,000 Yen.

Hitachi MB-6891

I did not reliably found out the difference between the Mark 2 and the Mark 1. Some sources say the Mark 2 would contain Chinese characters in ROM. Some English sources on this computer claim it used a Z80 CPU. This is, of course, wrong. It uses the same Motorola 6809 CPU as the predecessor and the successor model.

The final model of the 6809 branch is the 1983 Basic Master Level 3 Mark 5 (MB-6892). It was sold for 118,000 Yen.

Hitachi MB-6892

The RAM increased to 64 kB.

Motorola 68B09-based models

After the first branch of the Basic Master family using 6800 CPUs, the second one using 6809 CPUs, there was a final, third branch using 68B09 CPUs (Hitachi HD68B09E, to be more exact). The difference between 6809s and 68B09s is that the latter can clock twice as fast (i.e. at 2 MHz).

This third branch are the S1 family of computers. Apart from the much faster CPU, they also featured a 1 MB address space, 48 kB RAM, 48 kB VRAM (that can also be used for storing Basic programs if not in use), and not only Level 3 Basic, but also S1 Basic (an extension to Level 3 Basic created by Hitachi itself).

Hitachi MB-S1/10

The first models in 1984 were the MB-S1/10 and the MB-S1/20, the difference being that the MB-S1/20 has a Kanji (Chinese characters) ROM card.

Hitachi MB-S1/40

The next models, also in 1984 were the MB-S1/30 and the MB-S1/40. Both have a 1 MB floppy disk drive and the latter having a 2nd floppy disk drive and again having the Kanji ROM card.

Hitachi MB-S1/10,20,30,40
Hitachi MB-S1/10,20,30,40 prices and features

In 1985 we get the MB-S1/10AV with a Super Impose feature, 6 voices audio and 2 Atari-compliant joystick interfaces. We also get the S1/15 and the MB-S1/45 which are MB-S1/10 and MB-S1/40, respectively with an additional communication ROM card and a RS232C interface.

Limelight Interfield Systems JB-806E1-2

There is also a variant of the S1 called the Limelight Interfield Systems (JB-806E1-2) sold in 1985. As the Japanese Wikipedia page puts it: A model that has the same features as the MB-S1 released by Interfield Corporation. Although it may be considered as a compatible machine, the built-in FDD is 2D instead of 2HD, the cassette interface has the limitation that it can not be controlled from BASIC. Level 3 mode (mode B), ROM BASIC, image generator, RS-232C interface, and the joystick interface have been removed.

There was a final model called the “Basic Master 16000”. Despite its name, it was a PC-compatible machine that had nothing to do with the Basic Master family of computers.

In the Western world, all Basic Master models are very rare. In Japan, most models are still available in auctions from time to time for a, partially even reasonable, price. There, the S1 models seem to be the rarest of the family.



March 10, 2021

As I said in another blog post I find the computers of the 1980s French company Exelvision interesting and under-appreciated. Not only featured these computers (French) speech synthesis, but it had also one of the most interesting and quirky add-ons of the 80s: a digital drum computer (well, sort of)! Fitting into the naming scheme of Exelvisions products, it was called the “Exeldrums”. It was first sold in 1985 for 1200 French Francs (about 400 USD today).

Exeldrums: Complete product (without the manual)

Exelvision’s computer already came with a TI TMS5220 speech synthesis chip that was the same as in some of TI’s other products like the (last version of the) speech synthesis module for the TI-99/4A, the BBC Micro, and several arcade machines. It used something called “pitch-excited linear predictive coding (PE-LPC), where words are created by a lattice filter, selectably fed by either an excitation ROM (containing a glottal pulse waveform) or an LFSR (linear feedback shift register) noise generator. Linear predictive coding achieves a vast reduction in data volume needed to recreate intelligible speech data.” [Wikipedia]. The thing is that the Exelvision computers did not have a regular sound chip. In principle, you could use the speech synthesis chip also for sound effects, but it was a very complicated process to calculate the data for the synthesis chip given a target audio file. What Exelvision offered was to send them an audio cassette with the audio, then they would send this cassette to some TI labs in Dallas where a VAX computer would calculate the necessary data to feed the chip which you would get back as data on the cassette. As a result, even Exelvision’s own games have very sparse sound effects (and a lot of speech).

You could use a trick to generate some single channel audio, though. This trick consisted in using the cassette interface(!) and the timer to generate tones of a certain pitch and duration (see the last example in the section “Le composant audio” in [2] for an example).

So, all in all, the Exelvisions were not the best computers to do audio. Therefore, maybe in order to increase the attractivity of the machine to this market segment, two of the Exelvision engineers developed a cunning plan to use the computer as a drum machine (or at least a rhythm device). In true Exelvision fashion, an extension module was designed (all Exelvisions have an extension bay in the back), and some software written and put in a cartridge (they also had a cartridge slot in the front).

The module was designed around a rythm chip from Hohner (yes, the 150+ year-old German musical instruments manufacturer famed for their harmonicas). You see, Hohner used to manufacture a lot of different instruments in their day, and were in the 1960s and 1990 also famed for their range of innovative and popular electromechanical keyboard instruments. Between 1968 and 1976 they even produced (small) computers. In 1982 Hohner brought a successful series of home organs to market. Some of these models were sold in the US under the Wurlitzer brand, but stating on the case „Computer System by Hohner“.

This rhythm chip (the PCF0705) was manufactured by Philips. It is an interesting, but quite obscure chip. We know, of course, what it can do (see below), but apart from that we know basically nothing about it, not even a data sheet is available. This is because most probably, this chip was used only in Hohner products, and in Exeldrums…
All I found was a mention of this chip in a (Hohner designed) Wurlitzer “WX42 Keyboard Computer” because the seller mentions that you need to replace this chip if you want to get rid of the noise in the rhythm part of the keyboard…

Now, what can the Exeldrums do? Well, you can play 6 instruments in parallel out of a library of 17 drum and percussion sounds. These 17 instruments are clustered in 6 channels, and you can select one instrument per channel per time. The toms and the maracas are duplicated on two channels, so you can add them more often:

  • channel 0: bass drum, tom 1, tom 2
  • channel 1: hi-hat open, hi-hat closed
  • channel 2: cymbal, maracas
  • channel 3: snare drum, roll, brush, rim-shot
  • channel 4: maracas, tambourine, claves, tom 1, tom 2
  • channel 5: bell, hand clap

The resulting sound is probably good enough as a rhythm for a home organ, but it is no TR707: all sounds have the same length and the same volume.

The hardware module consists of the Hohner chip, a 32 kB ROM, a tiny (128 bytes) static RAM chip, and an analog/digital converter. You can hear the sound either via the TV or via the stereo cinch output at the back of the module.

Exelvision is a French company, producing computers mainly for France, and also the manual for the Exeldrums is in French. The software, however, has an English user interface 🙂

The basic screen is the classis TR707-style measure x sounds grid and you mark the beat where a sound shall be played. You can change the BPM, and you can have up to 57 sequences that can be saved onto tape or ExelMemory. In the software, you can use also one of 16 predefined rythms. Exeldrums can also be played from the Basic.

Here are all instruments (bass drum, tom 1, tom 2, hi-hat open, hi-hat closed, cymbal, maracas, snare, roll, brush, rim shot, tambourine, claves, bell, hand clap) played one after another each for 8 beats:

All instruments for 8 beats each, 50 bpm

There you have it: The Exeldrums digital “drum computer” module for the Exelvision family of computer in 1985. A rare and quirky add-on for a relatively rare French computer.


Sord M5 Pro

February 21, 2021
Sord M5 PRO

Recently, I bought a quite rare Japanese homecomputer at Ebay. It is the M5 Pro variant of the less rare (but still rare) Sord M5 computer. As the M5 was sold also in Europe, there is some information available on it. However, the M5 Pro was sold only in Japan, so this post focuses on the differences of the M5 Pro to the M5. As we will see, we can get rid of some misconceptions that have been made on the M5 Pro and Jr.

Sord Computer Systems was founded on 15 April 1970 by Takayoshi Shiina. In its first ten years it had become one of Japan’s fastest growing firms thanks to its success selling business micros on its home turf. The word Sord was derived from ‘SOftware haRDware’.

In 1982, Sord introduced its homecomputer model “M5”. It was meant to be mainly used as a games console. Therefore, it featured two joystick ports, only 4 kB of RAM, 4-channel audio, 32 sprites, and a cartridge slot. Also typically for game machines, the Basic was not built-in, but was delivered as a cartridge. Even more revealing is that the delivered Basic, Basic-I (I for Integer) did not feature floating point numbers or graphics commands. If you wanted these features, you’d need a Basic-F, or a Basic-G cartridge, respectively. The design of the case was very slick, and the PCB design and its build was high-quality and clean. The machine contained a dedicated graphics and audio chip and used Static RAMs. The keyboard was of a ZX Spectrum quality (because, again, this is not a serious business machine, and a 4 kB Basic program can also be entered by a lower quality keyboard). The M5 was introduced in other markets in 1983 (see the “The Register” article in the references for an account of the (lack of) success on the British market). There are also “CGL” branded M5s because CGL was the distributor of Sord in the UK.

Because the M5 was not a success, subsequent M5 models were only released in Japan, and not much is known about them. When we look at what we find on some popular web pages about the M5 Pro and M5 Jr., we find:

  • “[…] M5 Turbo, a faster version with “at least” 64KB of Ram […]. The M5 Turbo […] appear to have been released in Japan – as the M5 Pro […]” (The Register)
  • “M5 Pro […] were released with a built-in power supply unit (and more RAM?)” (old-computers.com)
    As we will see, most of that is basically not true.

What is true is that the M5 Pro and the M5 Jr. were introduced in 1983, one year after the M5. They were sold only in Japan. The price of the M5 Pro was 39800 Yen, and the one of the M5 Jr. was 29800 Yen. At the same time, the price of the M5 was reduced in Japan to 49800 Yen.

The point which the above sources are missing is that the M5 Pro is not the extended version of the M5, but the cost-reduced version of the M5 with the same features in the same case (but a different color scheme). It is neither faster nor has it more RAM. Also no built-in power supply, but exactly the same external power supply as the M5.

The difference between the M5 Pro and the M5 is the PCB. The M5 Pro PCB (Revision M5C-1B) is smaller, and uses different RAM chips (HM6116P-4 instead of TMM2016). The RF box is not mounted on the PCB anymore, but resides in the case next to the PCB.

There is also a strange switch that can be altered between H and L. On the M5 Jr. this switch is called “CH”, so I assume you can switch the antenna channels here.

The feature-reduced version of the M5 (and M5 Pro) is the M5 Jr. The missing features seem to be

  • the printer port
  • the video port (RF is still available)
  • the audio port

Addditionally, the power supply finally is integrated into the case. The PCB again is different from the M5 Pro (Revision M2C-01A). The case is slightly changed and the joystick ports moved to the front (which makes so much sense for a games console). The price is 25% less than the M5 Pro.

Z80 CPU, Japanese home computer: is the M5 family MSX-compatible? Well, no. It is using the same graphics chip as MSX computers, and a similar (but not the same) audio chip. But M5s have not enough RAM to meet the MSX standard, and they do neither have the MSX BIOS nor the MSX Basic.

While researching the M5 family, I found that the M5 Pro and the M5 Jr. were also offered in Japan under a different brand, namely as two models (?? and 84S) of the “Sanno Primary Computer” family. There are also other computers sold under this brand, but as the cases look the same as in the Sord case, they are easy to recognise. The Japanese “Sanno Institute of Management” had as its mission to computerize the Japanese schools. This program was lead by the Sanno Institute of Business Administration.

There you have it. The M5 Pro and the M5 Jr. are Japanese-market-only cost-reduced version of the M5. They are quite rare.

Technical Data

Manufacturer: Sord
Model: M5 Pro
CPU: Z80A @ 3.58 Mhz
RAM: 4 kB + 16 kB Video RAM
ROM: 8 kB
Graphics: Up to 256 x 192 at 16 colors, 32 sprites
Audio: 3 channels with 8 octaves, 1 noise channel
Interfaces: Power, Tape, Parallel, 2 x Game Pads, Audio, Video, RF (NTSC), Cartridge
Dimensions: 262x185x35mm, 800 g.
Introduced in: 1983
Initial price: 39800 Yen


IBM ThinkPad 730T

January 24, 2021

As some of you know, I’m very much interested in Tablet computers of the 1990 that are able to run PenPoint, the Operating System the company GO developed for the first “real” pen computers.

The computer IBM send into the race for this first pen computer was a new product, a tablet computer they christened “ThinkPad”. This product did not take off and they re-used the name for the new line-up of notebook computers. In order to fit the old tablet computer into the new naming scheme, they re-christened the tablet the “ThinkPad 700T” (T is the “slate” tablet version in the ThinkPad line-up).

All ThinkPads, of course, are basically PCs, and can run (in this case also) Windows. Therefore, the tablet ThinkPads could still be sold even though PenPoint as an Operating System (although much better adapted to a computer operated by a pen) did vanish very fast from the market.

The successor of the 700T was the 710T, which was then suceeded by the 730T. The final iteration of the T-Models was the 730TE. All of these models (well, at least the 700T and the 730T) can run PenPoint. If you want to know the differences between the T-Model, here you are:

RAM4-8 MB4-12 MB4-8, max 20-24 MB4-8, max 20-24 MB
Display10″ STN VGA, 8 Gray scales9.5″ STN VGA, 16 Gray scales9.5″ STN VGA, 16 Gray scales9.5″ STN VGA, 16 Gray scales
Weight2.8 Kg2.49 Kg1.77 Kg (2 Batteries)1.77 Kg (2 Batteries)
ThinkPad Tablet Slates Data

The 730T that I bought at Ebay was very cheap, but also clearly broken (which I knew). Its display has a strange wobbly-wave-like surface and has underneath some broken areas. The case is covered in a white crystalline powder and the material is very brittle and sticky. Therefore a good candidate for opening the device and contribute some PCB photos. Here they are.

730T PCB, top
730T PCB, bottom

The internal RAM (8 MB in my case) comes as a “Panasonic Memory Card”, a daughtboard with a strange connector. The RAM can be expanded with special PCMCIA cards.