Replacement for a DEC 7474 Chip

dave.g4ugm at dave.g4ugm at
Sun May 15 10:47:42 CDT 2022


I probably have some, and now I have found my ICL House Codes sheet I may even be able to identify them.
However I won't be in the same country as my stock for a couple of weeks.....
... and they are in the UK so getting them stateside may take some time.


> -----Original Message-----
> From: cctalk <cctalk-bounces at> On Behalf Of Chuck Guzis via
> cctalk
> Sent: 15 May 2022 16:12
> To: cctalk at
> Subject: Re: Replacement for a DEC 7474 Chip
> On 5/15/22 01:16, Eric Smith via cctalk wrote:
> > I don't think that worked on any TTL (or CMOS) 74x74 flip flops,
> > except maybe by accident if you shorted the output enough to draw Vcc
> > down (or ground up) enough to disrupt the FF, and then you have other
> problems.
> Checking my old Moto databook, the old FFs appear to be capable of
> having the outputs jammed.   At first glance, both the 7472 and 7473 FFs
> had unbuffered outputs.   Most early latches, likewise.
> Of course, the very early TTL was density-constrained, so FFs like the
> MC512/MC563 are of course without buffered outputs.
> --Chuck

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