hardware parity generation
ard at p850ug1.demon.co.uk
Wed Apr 18 16:49:12 CDT 2007
> On 17 Apr 2007 at 19:53, Tony Duell wrote:
> > > I think that the early databooks also show how to make a parity
> > > generator from a bipolar ROM.
> > You can make any combinatorial logic circuit from a ROM. Using one for a
> > parity tree seems ridiculously over-complex, though.
> Motorola marketed the MC4041 as something very much like this; it was
> a pre-programmed version of an XC170 ROM. Of course, they were also
> suggesting that the same ROM be used as a BCD-to-7 segment decoder
> (MC4039) and a 3-bit-to-8 demux (MC4038). Note that I said "early"
That last oen is totally ridiculous IMHO, given that a ROM contains an
n->2^n decoder to select an a particular location in the ROM determined
by the states of the n address lioes.
And if, as you said, it was early, there's even less of a justification.
Trasnistors were more expensive back then...
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