17 Apr
2006
17 Apr
'06
10:59 p.m.
On 4/18/2006 at 1:05 AM ard at p850ug1.demon.co.uk wrote:
That said, I think it is a pity there wasn't a
later TTL 7 segment
decoder chip (say a 74LS547 or something) that did display 0-F as you
might expect.
Well, the MC4039 used the Moto XC170 mask ROM as its core. The Moto data
sheet for the 170 mentions that codes 1010-1111 could be reprogrammed to
other characters. The 4039 had 1010=blank, 1011=dot, 1100=hyphen,
1101-1111=blank.
The MC14495 also does the hex-to-7 segment decoding.
Of course, one could always glom onto a few HP 5082-7340 displays...
Cheers,
Chuck