13 Oct
2006
13 Oct
'06
6:43 a.m.
Tony Duell wrote:
That's interesting, though. IBM must have believed that the 5150 would be a
global product and I'd expect that was the plan all along - so why put
circuitry on there for one market only?
As a curious
aside, the trimmer near the 14 MHz crystal on the 5150 is
intended not to adjust the time-of-day clock accuracy, but rather to adjust
color rendition with the CGA card.
But only if you're using a composite NTSC monitor (the colour subcarrier
-- 3.58-ish MHz -- is 1/4 of the master clock freqwuncy, of course). On
a TTL RGB monitor, like the 5153, the trimemr does nothing.