4004 and IC history / was Re: Vintage computer photogallery
Roy J. Tellason
rtellason at verizon.net
Sun Oct 14 16:17:26 CDT 2007
On Sunday 14 October 2007 16:07, Tony Duell wrote:
> I do remember 7545x parts that were dual 2-input gates with open
> collector outputs that could drive lamps/relays/etc. IIRC AND, NAND, OR,
> NOR gates all existed
Yes, and I've managed to scrape up data on those. If I'm not mistaken, that
dual floppy drive in the Cromemco we were talking about a bit ago uses a
bunch of those in there. (Looking...) Yup, here in the "299B Disk Drive"
manual I spot some 75453 and 75454 in several locations in there.
Those always struck me as extremely handy parts, I wonder if they're still
> The only 8-pin TTL chips I (just) rememebr the 7456 ands 7457 (I think)
> which were /50 and /60 counters (desigend to get 1Hz clocks from European
> or US power lines)
Those were LS56 and 57, or at least that's what's in my parts page, if there
were earlier non-LS versions of them I haven't found any data on them. I
don't recall ever actually running across those, but do remember some other
part number that was a similar package size and functionality.
And speaking of 50 and 60 Hz, I have this digital clock here that I got
*real* cheap, because it has a problem. it gains a LOT of time every hour.
Something like 10 minutes, maybe? I'm convinced that it's jumpered (or
something) for 50 Hz line power. :-)
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