Archive for December, 2008

Vintage Computer Myths Busted, part 1

December 31, 2008

In this series, I want to correct (or at least attack) some of the most widespread myths on rarity and prices of vintage computers that I found in Ebay or Wikipedia. Here we go:

Commodore SX 64 production number is only 9000

says e.g. the current German Wikipedia entry. Authoritative numbers are not available, but there are signs that SX64 are not very rare:

  1. Other sources about the production numbers put it more on the 30000 numbers scale.
  2. SX64s are the 2nd most frequent computers on my Ebay list, 2nd only to PET 2001s and more frequent than even a QL. The production numbers on the QL are said to be about 100000. Probably the SX64 is more attractive than a QL, but the production numbers are probably in the same range.
  3. This SX64 serial number database does implicitly suggest that there have been 5 different batches made: #1 with 50000 units, #2 with 1000 units, #4 with 17000 units, #5 with 11000 units, #6 with about 10000 units. In total that would be a production number of about 89000 units!

All in all I believe that the 89000 number is close to the reality because it explains the number of sales.

The Amiga 3000 is comparatively rare and sells now for more than the Amiga 4000

says again the German Wikipedia. Well, that’s an easy one as we have some official Amiga production numbers and our Ebay price list.

  • Amiga 3000/3000T: 14300 units, average price: 233 Euro
  • Amiga 4000/4000T: 11300 units, average price:  373 Euro

The rarest Amiga model though is the Amiga 3000T/040 with only 80 units sold in Germany (we do not have all the worldwide production numbers).

Mupid Mupid 1

December 31, 2008

Huzzah! A new old computer. Mupid’s Mupid 1, an old Austrian Prestel computer. In the article (which was written mainly by me 🙂 I assumed that about 8000 Mupid 1s have been built. The Collector’s Index is 5, the recorded sales is 2 (now 3..). As the Austrian post office even replaced Mupid 1 by Mupid 2s for free, I can imagine that not all of the 1s are still in existence, but who knows? Now I have to test whether it is working…

<update>Of course, it does not work (at least it seems so)</update>

<update 25.01.2009>Which is not suprising given the fact that some chips are missing (probably the RAM) 😦</update>

Forth Computers

December 30, 2008

Most 8-bit era home computers had a built-in Basic both as the programming language and the command line interface (in the 16-bit era and later on programming languages weren’t built-in any more and either a command shell or a graphical desktop system took over the task to handle the basic command needs of the user).

Well, “most computers” is not all computers and there are a few that had (or have) a built-in Forth dialect. I want to list these in this posting (if you click on the names, you find more in-depth information on

Jupiter Ace 3000 and 4000

This is the Forth computer per se. Widely known in collectors’ circles, these UK-built machines exist in a 9000 devices series (Ace 3000) and in a 800 devices series (Ace 4000). The 3000 series was the UK model while the 4000 was (mainly) the US model. Being mainly ZX81-likes with Forth, the programming language provided the far better computing performance than the Basic of the ZX81 even if the machine had only 3k RAM…

Unfortunately, the company soon ceased operation because the machine was behind the then state of the art.

The Collectors Index of the 3000 model is 13, of the 4000 model is 3. The average price of the 3000 model is 214 Euro (7 sales), of the 4000 unknown (since there were no recorded sales).

Here is a link to the definitive Ace page,

Micronique Hector HRX

Far lesser known than the Aces, also a French company built a Forth-based machine, namely the Hector HRX from Micronique.  Nothing seems to be known on the number of produced machines, but it should be small. The Collector Index is only 5, and the sole recorded sale was the one to me 🙂 (it did not go via Ebay, but a french gentleman reacted on a small ad on a french board). Therefore, the average price is not very trustworthy… In general, french computers have a small collectors community, not only, but also because the french have all documentation and the texts stored in the computer in french :-).

Micronique Hector MX

The MX was the last model, featuring both Basic and Forth. It is a very rare machine with a Collectors Index of 0 and no recorded sales, but it seems some collectors have it.

<update 14.01.2009>

Canon Cat

Oops, now I forgot another interesting Forth computer, the Canon Cat. This was a very rare computer that “was targeted at low-level clerical workers such as secretaries.” “The Cat featured an innovative text based user interface that did not rely upon a mouse, icons, or graphics. The key person behind the Cat was Jef Raskin, an eclectic gadgeteer, who began the design of the Cat during his work on the first Macintosh project at Apple Computer in 1979.”

The Cat’s built-in software contains not only a Forth interpreter (see this link on how to activate Forth on this machine), but the entire built-in software was written in Forth.

The prototypes of the Cat called Swyft and the SwyftCard (an Apple II card) from Jef Raskin’s company Information Appliances therefore were also equipped with Forth, but the first is a prototype and the latter not a computer.


OpenFirmware (OpenBoot)

This is not a computer, but a booting or firmware architecture used by quite some computers based on Forth. This means that on these machines, you can reach a built-in Forth interpreter prompt. Unfortunately, you can do this only after switching on the computer, i.e. in the boot phase. The computers that use this architecture are:

  • Sun SPARC systems
  • post-NuBus PowerPC-based Apple Macintosh computers
  • Pegasos
  • IBM POWER systems
  • OLPC XO-1 (yes, the famous $100 Laptop)

These are all common (well, except the Pegasos) computers that are not rare, or still actual products.

I will not start listing printers, although 1) printers are computers, 2) Postscript is some-sort-of-Forth-dialect 🙂

Ebay: Unusual CBM 4008 with cassette deck

December 30, 2008

This is a CBM 4008, but with a built-in cassette deck. The back sticker identifies it as a PET 2001. It also has a DEMO sticker on it. Maybe a prototype? Unfortunately, it is not functioning.

Apple Newton Prototype

December 23, 2008

Lately (although before I started this blog) there was an incredible item on Ebay: an Apple Newton Prototype.

Apple Newton Prototype

Apple Newton Prototype

It was sold for 250 Euro.

Ebay prices and shipping

December 23, 2008

One thing that restricts the achieved prices in Ebay is the refusal of a seller to ship items internationally or to not even ship the items (i.e. if the computer is pick-up only).

So, as a seller, offer international shipping if you want to achieve the highest possible price.

As a seller, look for pick-up only items in your area or ask a friend in the corresponding country to receive the packet and send it to you. Do not forget the customs fees when crossing country borders.

Finally: The Price List

December 11, 2008

I finally did it! I published the first version of my what-old-and-rare-computers-cost-at-Ebay list including such indispensable data as:

  • the overall average price per computer: 215 Euro
  • the overall median price per computer: 166 Euro
  • the overall market volume: 214620 Euro

always related to

  1. the list of recorded computer models (only some models are in my focus)
  2. the recorded sales (I almost got all days covered, but lost about 2 weeks and maybe oversaw the one or other sale)

This first version contains the data of 1000 sales sampled between March 16, and today, i.e. 270 days.

The models that sold most numbers were:

  • Atari Falcon 6.4%
  • Commodore SX64 13.4%
  • Commodore PET200 15.9%
  • Commodore Amiga 4000 6.1%
  • Sinclair QL 12.3%
  • Sinclair ZX80 6%

i.e. 6  models had over 60% of all sold computers!

The most expensive regularly sold computer I recorded was an Altair 88000 for 2361 Euro. The most expensive sales of the not so regularly sold models were a Golden C64 for 3432 Euro and a C65 for whopping 7191 Euro!

The list is a .xls file readible by OpenOffice Calc or Excel. The first page gives you some overview data. The second page is the most important one giving you the

  1. Company (i.e. manufacturer)
  2. Model
  3. the number of devices produced (hypothesis 1)
  4. the number of devices produced (hypothesis 2)
  5. average price in Euro
  6. number of recorded sales
  7. the overall amount of revenue of this model (i.e. column 5 * column 6)
  8. The collector index of this model (i.e. the number of devices of this model the registered collectors  claim to have on this web site)
  9. Remarks

The fourth page collects the prototype models (which are not part of the overview data). The sixth page lists a few clones. The detailed recordings of the sales start at page 9, one page per model. These pages are used to calculate the values on the second page.

Finally, here is the link to the list.

I’d love getting some feedback on it (positive or negative).

IMS Multi-Media One (MM/1)

December 9, 2008

The following is an article I sent to but it never reached somehow the light of publication:

This extremely rare computer was designed as a successor of Tandy’s CoCo3 computer sporting OS/68k, but using a 68000-like Microprocessor. It came as a screw-it-together kit for a standard PC small tower case, bundled with Microware’s OS/68K, including a structed Basic, Emacs, and the C compiler, which was well beyond K&R but not quite ANSI. It used a 66470 VSC graphics chip developed for CDi. The MM/1 also has a backplane board (just a simple bus with a resistor pack or two and a couple header connectors) that connects the CPU board with the I/O board. The CPU board has floppy, video, keyboard, and a couple serial ports built in, along with 1M of RAM soldered onto the board that serves as system and video RAM. The I/O board added (I think potentially 3) more serial ports, two parallel ports, SCSI, RTC, 2 8-bit ADC/DAC chips for sound in/out (quite rare at the time), and joysticks, and up to 2M additional RAM in 30-pin SIMMs. There even was a MIDI interface as an option.

Somebody stated: “The MM/1 was always supplied as a kit (not much assembly required), to get around the FCC RFI limits.  I can assure you that an MM/1 obliterates all hope of FM or TV reception in the same house!”.

Somewhere along the line, IMS sold the rights of the MM/1 to Blackhawk Enterprises (David Graham) in about 1994. Blackhawk sold remaining stock of IMS MM/1 equipment, and also had a redesign of the backplane and the I/O board. In this version, the backplane becomes a memory board that supports up to 2 4M 30-pin SIMMs. Memory is moved off the I/O board, and a later version of the SCSI chip is used.

But since there were problems with the Version 2 I/O board, David Graham also sold AT306 motherboards as the MM/1b while trying to work out the bugs in the SCSI interface of the original MM/1. The AT306 is a motherboard with a Motorola 68306 processor and an ISA bus so you could plug PC peripherals in and take advantage of cheap commodity hardware, if you could cook up drivers. Even though the hardware was very different from the original MM/1, David Graham called it the MM/1b because the licenses he had for OS-9/68K and the OS-9 Port Pack were valid “only for the MM/1”.

It is said that only between 200 and 500 of these machines have been made.

NAME Multi-Media One (MM/1)
TYPE Home Computer
YEAR 1991
CPU 68070
SPEED 15 Mhz
GRAPHIC MODES 640 x 208,640 x 416 interlaced
COLORS 8 bit
SOUND Stereo Digital Audio in/out (8 bit)
SIZE / WEIGHT ? / 11 Kg
I/O PORTS Video, floppy, keyboard, stereo audio, SCSI, RTC, joysticks, 2 parallel ports, 4(?) serial ports
POWER SUPPLY Internal power supply unit
PRICE MM/1b Mainboard: $400


Review of the “Vintropedia” book

December 9, 2008

The following is a review on “Vintropedia”, a book that claims to gives relevant prices on many old computers.

Vintropedia 2009 – a review

Fritz Hohl, 10.09.2008

Recently, the first edition of a Price Guide book was published that contains also prices for about 3300 computers (completed by prices for 1800 consoles, 2000 accessories, and 7000 pieces of software). Every item makes one line in the book. In the case of computers, each line contains information on

  • the manufacturer
  • the model name
  • launch year
  • CPU, number of colors, amount of RAM and ROM, and finally
  • the price in GBP

In addition, the books contains 15 vintage ads.

Clearly, the amount of gathered data is impressive and alone having the list of models is good to have as a book.

Still, the most important data are the prices, and here some questions pop up:

  1. can such a thing like an accurate price list for all computer models be done at all?
    First, from which do you get such a price? From Ebay? From what some collectors are willing to pay? From the perceived “rarity” of the model? It is not only unclear what sources the authors use, it is also unclear whether this is the same price. Second, time is an issue. Prices change over time. Taking into account sales from 5 years ago might give you a fals impression when it comes to what price a model would achieve today. Third, do you get a statistically sound data base? Some models are so rare (or have so low demand) that there are barely sales that give you a price. Last, but not least, this work probably cannot be done with reasonable effort. You simply cannot monitor all sales on a collector level worldwide. Even monitoring all ebay data is something you can achieve only half-automatically, and it is still a major task (that to be honest I doubt the authors have done).
  2. in which region this price should be valid for?
    First, prices also depend in the region a computer is sold. Second, as exchange rates change, one currency does not “fit it all”. A price a collector is willing to pay is often a round number, e.g. $1000. Now, $1000 are 710 EUR today and maybe 1200 EUR tomorrow.
  3. can one price do it all?
    Prices for a computer depend not only on several variables like being boxed, or having a special accessory. These variables change the price for different models in a different way or are even different for different models (e.g. a video toaster raises the price of an Amiga whereas this device does not exist for other models).

As I am very interested in prices for rare vintage computers, I tried to assess the “price accuracy” aspect of this book using my own 6-months-spanning records of ebay.(com,uk,de,fr,it,es) sales of some rare computer models.

For 73 models I estimated the differences between their prices (in GBP) and my prices (in Euro). Out of the 73 models, 31 (or 42%) had about the same average price. 7 of the 73 (or 10%) had a higher price in their list, 11 (or 15%) had a lower price. For 24 models (or 33%) their price differed strongly from my price or my intuition (all prices in Euro),e.g.:

Model Vintropedia My List
Acorn Atom 405 107
Apple Lisa 1 1245 -*
Atari 800XE 118 39
Atari ATW800 342 -*
Atari Falcon 62 270
Atari ST Book 119 546
Be BeBox 44 394
Canon Cat 50 -*
C64 Golden 560 2726
Amiga 3000T 62 -*
Mattel Aquarius II 93 -*
Micronique HRX 31 -*
Oric Telestrat 81 -*
Rockwell Aim 65 311 171
Sinclair QL 250 83
Sinclair ZX80 342 173
Tatung Einstein 256 436 60

*I would buy any amount of these machines for this price. Just contact me 🙂

I also tried to find out (in a blackbox manner) how they find their prices. The first thing you find is that there are a fixed number of prices:
10-100 GBP in 5 GBP steps
100-200 GBP in 25 GBP steps
200-1000 GBP in 50 GBP steps
1000-3000 GBP in 250 GBP steps
and some “special prices”, namely 5000, 9000, and 12000 GBP each for a certain model.

To me, this seems to hint to a category-based approach where each model was given a certain category (“is as rare as”?) and then the categories were ordered and priced according to the above scheme. This is of course only a speculation.

For me, the overall conclusion is this: First, the price list is better than having no information at all, and I do not know a comparable, actual publication that tries to achieve the same goal. Second, you have to be aware that there are some hefty inaccuracies in there. Third, the way the list is done might not give you the price information you need. The goal of the authors seem to be to increase the accuracy of their prices over time by taking into account the (maybe angry?) feedback of users. Until this happens and several iterations delete the major mistakes, this book remains a source for experts that know how to interpret these numbers.

VINTROPEDIA – Vintage Computer & Retro Console Price Guide 2009
Michael Starr(Author), Craig Chapple (Author), Arianne Wolodarsky (Illustrator)
328 pages, Lulu Press; 2009 edition
ISBN-10: 1409212777, ISBN-13: 978-1409212775
Price: £16.00 – 22.50

Shall I drop QLs and SX64s from the focus?

December 9, 2008

Of the about 1000 recorded ebay sales, 12.5% are QLs and 13.5% SX64s. Together they have a (number-wise) market share of 26%. I’m always looking for models to drop from the list (in order to make the life easier for me) and to add other models (whose rarity I did not know) to it.

What do you think? Should I drop these two models from my focus, thus let them in the list, but do not record new sales? I think I have enough data on them now to have some relevant data on most parameters (in short: to predict the price in average).