12 Apr
2002
12 Apr
'02
11:46 a.m.
Richard Erlacher wrote:
Ok then how about some NICE NIXIE TUBES then (grin).
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
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.
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