24 Aug
2014
24 Aug
'14
6:59 a.m.
On Sat, Aug 23, 2014 at 03:32:45PM -0400, Clem Cole wrote:
BEGIN - old guy's memories ....
I see your old guy memories and "raise" my sort of old guy memories.
This is a bell labs blit story. It relies heavily on 7 bit clean stuff.
I'm not entirely sure this ever worked reliably but here is what we did.
I was a grad student at UW Madison and shared an office with another guy. We
had a serial line to the computing center across the street. We had a blit,
loved it. We wanted two.
I found an 8051 (or whatever version had a programable prom and 3
serial ports). I wrote the code that used the 8th bit to say whether
it was my blit or my office mate's blit. Burned the proms into two
of those, convinced the lab to let me put one on the other end and
presto! Two blits running side by side, two happy TA's.
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Larry McVoy lm at mcvoy.com http://www.mcvoy.com/lm