Galaksija (computer) - Trivia

Trivia

• Approximately 70% of CPU time was used just to generate video, which made Galaksija relatively slow in normal operation. This was unacceptable while saving or loading data from the tape so video generation was disabled during tape operations. There is also a way to disable (and re-enable) video generation from BASIC when "fast computation" is required. With video disabled, built-in BASIC interpreter was in many instances able to outperform interpreters of other home computers of the time.

• Galaksija's BASIC has slightly different names for standard commands (e.g. BYTE instead of PEEK and POKE, OLD instead of LOAD, etc.). This was done to assure that most commands begin with different letters. Not only this helps the interpreter in recognizing the command but also allowed all commands to be abbreviated to one letter followed by a dot (e.g. "P." instead of "PRINT") and, thus, take less memory for the same program, albeit with reduced readability.

• Galaksija's interpreter can report only a few error messages - "WHAT?" (used for syntax errors), "HOW?" (indicating that requested operation is theoretically impossible) and "SORRY" (errors due to system limitations). This made more ROM space available to code.

• "READY" prompt (bytes in ROM representing it) is also used as code in video generation routine.

• To simplify "do-it-yourself" building and reduce cost, the printed circuit board was designed as single-layer (one-side) board. This resulted in a relatively complicated design requiring many components-side connections to be made using wires.

• Galaksija's case was not pre-built. Instead, the guide suggested it to be built out of the printed circuit board material (such as Pertinax) also used for the mainboard. Thus, the top, sides and reinforcements were soldered together to form the "lid". acrylic glass was recommended for the underside. The guide included instructions on cleaning, painting and even decorating the assembled case. The name "GALAKSIJA" and decorative border were to be added using Letraset transfer letter sheets after the first (white) coat of paint but before the second coat of final colour. After the paint dried, transferred decorations were supposed to be scratched off, exposing underlying white paint.

• Among standard ways of distributing software, Galaksija programs used to be broadcast over FM Radio "Beograd 202" in a show Ventilator 202, hosted by Zoran Modli. At 280 bit/s, a mere 2 KB program would take a whole minute of characteristic noise that only computer enthusiasts enjoyed.

• "Dots" of pseudographic mode were not all of the same height. They were all 3 pixels wide and 1 pixel gap existed between them (both horizontally and vertically). In one character, there were two dots horizontally and three vertically. The top and bottom dots in a character were 3 pixels tall, and the middle ones were 4 pixels tall.

• Generated video signal was made for PAL equipment, but does not fully conform to its timings. Instead of 15,625 lines per second (625 lines 25 times per second) Galaksija generated full 16,000 because it was easier to fit in CPU timings (exactly 192 clock ticks) per line, while keeping the 25 frames (50 fields) per second. Instead of 312.5 lines per field, this results in exactly 320 lines. Due to a missing half-line to facilitate interlacing, Galaksija's video output was essentially progressive, albeit because it never comes to the "second field". This did not create any usage problems as it was well within tolerance of the video equipment.

• The keyboard is laid out such that keys have their own memory-mapped addresses that, in most cases, follow the same order as ASCII code of the letter on the key. This saved the ROM space by reducing lookup tables but significantly increased the complexity of single-layer keyboard PCB such that it alone required 35 jumpers.

• The original Galaksija's ROM lacks support for auto-starting programs after they have been loaded from the tape (a feature common in similar computers of the time). Users had to start each program manually after the loading with a "RUN" command. This was an intentional attempt to prevent copy-protection and to encourage sharing of software between users.