On 06/12/2018 05:44 PM, groepaz@gmx.net wrote: > Am Dienstag, 12. Juni 2018, 17:05:20 CEST schrieb Mia Magnusson: >> Den Sun, 10 Jun 2018 15:50:50 -0500 skrev Segher Boessenkool >> >> <segher@kernel.crashing.org>: >>> On Sun, Jun 10, 2018 at 10:17:17PM +0200, Gerrit Heitsch wrote: >>>> On 06/10/2018 09:46 PM, Segher Boessenkool wrote: >>>>> On Sun, Jun 10, 2018 at 06:42:02PM +0200, Gerrit Heitsch wrote: >>>>>> On 06/10/2018 05:36 PM, Segher Boessenkool wrote: >>>>>>> http://siliconpr0n.org/map/mos/6526/mz_mit20x/ >>>>>>> >>>>>>> The ports are the low half of the pins (PA on the left, PB on >>>>>>> the right). >>>>>>> >>>>>>> (I have a .xcf if anyone is interested, marked quite a few >>>>>>> signals, but I haven't done the port stuff very much. It's >>>>>>> about 400MB). >>>>>> >>>>>> That looks quite different from the one I posted. Looks like MOS >>>>>> did quite a bit of redesign between the NMOS 6526 and the HMOS >>>>>> 8521 (which still got labeled 6526). Might explain the little >>>>>> differences in the way they behave. >>>>> >>>>> No, this is an actual 6526r4. This is an 8521r1: >>>>> >>>>> http://oms.wmhost.com/misc/MOS_6526A_CIA.jpg >>>>> >>>>> (and this is an 8520r4, the CIA used in amigas; it has a different >>>>> TOD clock, and as you can see it's different from 8521 in other >>>>> ways, too. But clearly 8520 and 8521 are more related. The >>>>> lineage is almost certainly 6526 -> 8520 -> 8521: >>>>> >>>>> http://siliconpr0n.org/map/mos/8520/mz_mit20x/ ). >>>> >>>> Yes, but the 8521 is a drop in replacement for the 6526 (I have a >>>> C64 Board with a 8521R0 on U2) and later revisions of that chip >>>> have been labeled as '6526' again, probably to avoid confusing the >>>> customers. You can tell them apart by the datecode or by the '206A' >>>> or '216A' next to the datecode. >>> >>> _Almost_ drop-in replacement, yes. But the die photos are really easy >>> to tell apart (an 8521 does not say "6526" on the die, it says >>> "8521"). >> >> I can't remember which versions, but at least some version of the CIAs >> can only be used as one of the two CIA's in a C64. Using it as the >> other CIA causes keyboard problems. > > no, both can be (and are commonly) used in either position > >> And when using it as the CIA that >> generally works causes interrupt failure in the common diagnostic cart >> (the one that's not called dead test, not sure if it has a better name >> than diagnostic). > > that is correct - some of those diagnostic tests fail with the "new" CIA Only if they don't take the 'new' behaviour into account. GerritReceived on 2018-06-12 19:00:09
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