Monday, December 22, 2014

Intel 1405A...

Intel 1405A...  One of my earliest digital designs was for a video board.  It used a character generator ROM and 14 of those Intel 1405A shift register memories to provide a 7 bit wide, 1024 character memory to store the 16 lines of 64 characters.  By today's standards it was laughably primitive.  By the standards of 1975, when I built it, it was like something out of science fiction.  I found those 1405A parts in the back of one of the early computer hobbyist journals (it may actually have been TCH) at a discounted price.  That find inspired me to design and build that video board, copying many ideas from one of Don Lancaster's cookbooks.  I built the entire thing with wire-wrap, with the board being roughly 10" x 6".  When I finally got that thing working, you could hear me whooping and hollering for miles :)

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