13 Jan 2005
First Computer

My friend the orangeguru posted this little tale of his first computer yesterday. So, since I'm another year older today, I figured it would be interesting to do the same. The year was 1979 ... at the left is a photo of a device very similar to the first computing device I owned: the COSMAC Elf. Mine looked slightly different, as I had mounted it in the case of an old Radio Shack CB base unit.

  • Processor: RCA 1802 (8 Bit CMOS), 1 MHz
  • RAM: 256 bytes
  • ROM: none
  • Display: two seven segment LED's

I also had a speaker wired across the Q line of the processor to produce some simple audio output. I could've expanded the RAM to a whopping 1 KB, but that would've cost me an extra $100, and besides, what would I ever do with all that free memory?

Programming was a simple matter of setting the eight switches on the front panel to the desired machine instruction (in binary) and them pressing the 'Load' button. My major software accomplishment: programming the little thing to play the song Down in the Valley (the link is to a MIDI version that sounds a whole lot better than my monotone creation). If I recall correctly, it took several hours to figure out exactly how to manipulate the line to get the right tones, and then program the machine. The program ran for about 30 seconds...

Amazingly, there is still a community of COSMAC Elf users/builders on the 'Net. In fact, the "blueprint" (from Popular Electronics, August 1976) I used to construct my little electronic marvel is actually up on the 'Net here.

OK, now I feel really old.

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