TTL computing

From: Ben Franchuk <>
Date: Fri Apr 12 11:46:21 2002

Richard Erlacher wrote:

> It doesn't help having all the unused states represented in your ROM.
> Discrete implementations and programmable devices both cover all the REQUIRED
> states, and having other states supported is certainly unnecessary, as well as
> potentially hazardous.
The advantage of a prom it is easier to change than hard wiring,
provided you have a programer. Since I am having problems with getting
my FPGA cpu a serial prom I just may endup using TTL and hard wiring the
logic. If nothing else it looks impressive on several boards.:)

> >
> > BTW B.G micro does sell 74LS170's, and AM2901's.
> I've not needed a '170 in over two decades. I do have a supply of '670's,
> which are the tristate version of the same device, and I just this week
> finished an application using a couple of them in a display application.
> They're pretty handy when you have no synchronization between the inputs and
> outputs, and, as was the case in this 7-segment display device, when your
> inputs are byte-wide, and outputs are nybble-wide.
> > --

Ok then how about some NICE NIXIE TUBES then (grin).
Ben Franchuk - Dawn * 12/24 bit cpu *
Received on Fri Apr 12 2002 - 11:46:21 BST

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