Casio PB-100

Computing power was not cheap in the 1980’s. And this was also the time where things started to shrink in size. The PB100 was a one of those computers that had awesome power  – read on to see how much!

Released in 1982, I bought my PB100 in 1983 and immediately started to program it in BASIC. The raw power of this computer that was the size of a calculator was pretty impressive  – for it’s time.



It came with 1KB (NOT a typo) of RAM which resulted in only 544 bytes for BASIC, which was really limiting, even in 1983.
There was a memory module called the OR-1 (sad that I remember) that upgraded it to 1568 bytes of user memory. This allowed for many BASIC programs to be written. There are 10 area – P) to P9 where you would store your programs.

Courtesy of Google , the main circuits of the PB-100 were made up of two chips. Processor logics, ROM, display driver, and keyboard controller were integrated in a single CMOS VLSI chip HD61913, which had an external 4-bit bus. The second main component was a HD61914, which is a 8192-bit static RAM organized as 2048 words by 4 bits.

What accessories were available? Well, you could get a cassette interface  (for storage, but I have not idea how it would of worked), plus there was also a thermal printer available for it. I never actually saw what these printers looked like or knew anyone that had one.

The PB100 was fairly cheap to run – 2 X CR2032 button cells powered the unit.

Did you have one? What did you you do with it? Leave a comment below.



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