12 Apr
2002
12 Apr
'02
1:30 p.m.
I'm afraid that the Nixies are too large for this handheld application.
Dick
----- Original Message -----
From: "Ben Franchuk" <bfranchuk(a)jetnet.ab.ca>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, April 12, 2002 10:46 AM
Subject: Re: TTL computing
and
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
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 *
www.jetnet.ab.ca/users/bfranchuk/index.html