Den Tue, 8 Jan 2019 21:58:39 +0000 skrev smf <smf@null.net>: > On 08/01/2019 21:32, Thom Cherryhomes wrote: > > I do want to seriously bitch-slap IBM for doing such a horrible job > > on the CGA card (no dual ported memory... _FOR A CARD THAT COST > > HUNDREDS OF DOLLARS BY ITSELF_ ) > > I think you underestimate how much 16k of ram cost them in 1981. > > Was dual ported memory even available back then? Dual ported memory is an expensive solution to what's usually an incorrectly formulated problem. The solution would be to use fast enough memories to be able to do as in 8-bit computers. > They couldn't use the same trick as the c64, the cpu and the graphics > card saturate the memory on their own. > > They could have just halted the cpu if it tried to access the ram > while the graphics card was displaying, but it would have been even > more expensive. No, inserting wait states would had been more or less free. That would had in practice made the CGA card's memory having "badlines" every line. Still faster than having to wait for vertical retrace to avoid "snow". -- (\_/) Copy the bunny to your mails to help (O.o) him achieve world domination. (> <) Come join the dark side. /_|_\ We have cookies.Received on 2019-01-09 00:00:03
Archive generated by hypermail 2.2.0.