Am 10. Juni 2018 13:21:22 schrieb smf <smf@null.net>: > On 10/06/2018 10:57, André Fachat wrote: > >> I find it amazing what chip designers sometimes do that really annoy >> the programmers or users. And this sometimes even means additional >> hardware so it can't be attributed to scarcity of resources (like I >> guess clearing interrupt flags by just reading the flags....). > > I assume for cost purposes they don't keep the last output value when in > read mode, so when you switch back to output mode then zeros is probably > the lesser of two evils. You mean they have a single latch only, reused for input and output? Probably more logic around to make that work but could be.... > Trying to replace a mos chip with an intel chip is blasphemy :-) Guilty :-) And I would still happily replace the 6551 with a 16550... :-) AndréReceived on 2018-06-10 14:01:11
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