Archive for January 10th, 2020

Umtech VideoBrain Family Computer

January 10, 2020

Recently, while searching for another computer, I found a computer in a box in another box that I obviously bought some years ago, but then completely forgot about it. What was even funnier is that I saw this exact model on ebay some days ago and actually thought about bidding for it (which I didn’t). This computer finally sold on ebay for over €850 or $960 even without power supply or joysticks. I do not remember, but I am pretty sure I did not pay that type of money whenever it was that I purchased it.

Okok, to the point: Let me introduce you to the VideoBrain, sometimes also called the VideoBrain Family Computer, the sole model produced by a company called Umtech from 1977 on.

Very unusual for a home computer was the full travel, 36-key keyboard it featured. However, it is said to be poorly designed and difficult to use. Certainly, the choice of functions on it looks very weird.

The VideoBrain had no built-in computer language. However, there was one language available as a cartridge from December 1978. If you would had to guess which language one should offer to home consumers, only a few people would come up with the choice of VideoBrain: APL/S. APL is a programming language which (according to its Wikipedia page) is influenced by “mathematical notation” and influenced itself such crowd pleasers as “MATLAB” and the “Wolfram Language” :-).

Regarding the VideoBrain and APL/S there is a magnificient audio recording from the Third West Coast Computer Faire conference in 1978. This recording was made during the presentations of the Conference. Thir first and second presentation are:

  • Ted Haynes: Videobrain and the APL/S Language
  • Robert G. Brown: An Introduction to APL/S: A Modern Computation Language for Personal Computing

and you can listen to them in very good quality using the last link in the references.

And, you heard it here first, the $150 APL/S cartridge actually had not only ROM, but also more RAM (if you listen to the presentations from the last paragraph). This is also hardly surprising as 1 kB of RAM is hardly enough for a (later) Sinclair ZX81 with its efficient, token-based program representation, let alone APL, a language that can handle entire number arrays with a single operator. <update>[Brown78] states that the cartridge had 13 kB of ROM and 1(!) more kB of RAM.</update>

When you listen to the presentation of Robert G. Brown, you can also hear his rationale of offering APL as opposed to Basic, namely the higher productivity and better degree of programming structures. These are, of course, honorable reasons for a computer scientist, but seem a little bit odd for an entry-level computer with hardly enough memory to actually have program readability problems :-).

The above presentations are also contained as text articles in the Proceedings of the Third West Coast Computer Faire conference. But if you are interested in the APL dialect, also Byte had an article by Robert G. Brown, the author of APL/S in the December of 1979 issue, and this issue is online (see references below).

The main differences of APL/S to APL are:

  • APL/S is a subset of APL
  • all these pesky special characters the original APL needs as operators (like the arrow and the star-im-a-circle) are replaced by ASCII strings
  • arrays in APL/S are restricted to one dimension and subscript expressions must evaluate to scalars
  • APL/S adds control structures like IF and WHILE

APL/S uses a two-part user interface. In the lower half the user can enter and execute code. The upper half is reserved for bar charts. For variable names, only the first four characters are used.

The VideoBrain was the first home computer system where the software was available as cartridges. These could contain of up to 12 kB of ROM. Fewer than 25 software titles were ever markteted for the VideoBrain.

The used CPU is quite old and exotic. It is a Fairchild F8, which consists of two chips (the CPU and the “Program Storage Unit”. This sounds awkward, but was actually a technical achievement in 1975, at a time when earlier CPU designs distributed the needed functionality over a larger number of chips (sometimes 7 or more chips). Later on, CPUs assembled all functions in one chip. As a result, the F8 was quite economic, which, according to [CPU Museum], made it in 1977 to “the world´s leading microprocessor in terms of CPU sales”. However, as we know, the number of computers exploded only after 1977, and these computers used other CPUs. Therefore, it is not surprising, that there aren’t that many F8-based computers. There is the VideoBrain, and there is Fairchild’s own console, the Channel F Video Entertainment System from 1976.

Due to the high cost of RAM at that time, the machine came only with 1 kB. However, it had 4 kB of ROM, providing four built-in programs: a simple text editor, a clock, a count down timer, and a color bar generator.

The basic computer itself does ntot have any possibility to save data, you had to buy the “Expander 1” if you wanted to have cassette tape recorder interfaces (and two RS232 interfaces). The “Expander 2” was a 300 baud modem.

Graphics on this machine seems to be complicated. [SeanRiddle] says “This document describes the VideoBrain grapics hardware. It is a sprite engine, capable of displaying 16 sprites simultaneously. The control registers are documented pretty thoroughly. The sprites are monochromatic, but each can be a different color. There is one bit each for RGB, and 2 bits of intensity info (but maybe only 2 intensity levels are usable). The registers allow for a sprite up to 248×256 pixels, positioned on a grid 256×512 pixels in size. Sprites can be displayed at twice their horizontal or vertical size. There are 2 “display lists” for setting the y position and drawing priority of the sprites. There is also a mode called “xcopy” that replicates the first byte of a sprite horizontally.”

The computer was not widely available, but was sold for a short time by Macy’s department store. As you can imagine, the VideoBrain was not a large success, and it vanished from the market after 3 years.

The Wikipedia article on the VideoBrain talks about the fact that the VideoBrain had no real defined target audience and therefore could not satisfy anyones needs (in contrast to the Apple II), and that’s certainly true. From my point of view, the VideoBrain tried to be both a games console (small memory, cartridge slot, 4 joystick interfaces, no cassette interface) and a computer (full keyboard, programming language available from 1978, computer interfaces available in expansion module), but did both things badly.

Technical Data

  • Manufacturer: Umtech
  • Model: VideoBrain Family Computer
  • CPU: Fairchild Semiconductor F8 @ 1.79 MHz
  • RAM: 1 kB
  • ROM: 4 kB
  • Graphics: 16 colors, sprite engine (see above)
  • Interfaces: 4(!) joystick ports, TV RF connector, cartridge, expansion port
  • Released: 1977
  • Initial price: $500 (basic device)

References