On 06/10/2018 05:36 PM, Segher Boessenkool wrote: > On Sun, Jun 10, 2018 at 04:59:52PM +0200, groepaz@gmx.net wrote: >> Am Sonntag, 10. Juni 2018, 16:52:24 CEST schrieb Segher Boessenkool: >>> On Sun, Jun 10, 2018 at 04:41:41PM +0200, groepaz@gmx.net wrote: >>>> Am Sonntag, 10. Juni 2018, 16:38:24 CEST schrieb Segher Boessenkool: >>>>> On Sun, Jun 10, 2018 at 04:06:21PM +0200, groepaz@gmx.net wrote: >>>>>> Am Sonntag, 10. Juni 2018, 15:55:10 CEST schrieb Segher Boessenkool: >>>>>>> On Sun, Jun 10, 2018 at 03:39:42PM +0200, groepaz@gmx.net wrote: >>>>>>>> if its similar as with what ppl did with 6522 and 6526 (i would >>>>>>>> assume >>>>>>>> it >>>>>>>> is) - then expect every dirty trick you can imagine being used by >>>>>>>> real >>>>>>>> world software. for example even the subtle differences between >>>>>>>> the >>>>>>>> port >>>>>>>> drivers of port 1 and port 2 are relevant in 6522/26 emulation. >>>>>>> >>>>>>> (Is there any difference on the 6526?) >>>>>> >>>>>> yes, unfortunately its not documented in detail anywhere (like in the >>>>>> 6522 >>>>>> datasheet) - but experimentation shows that very likely the port >>>>>> drivers >>>>>> have the exact same differences/properties: >>>>>> >>>>>> the obligatory test program is here: >>>>>> >>>>>> https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/CIA/ciapor >>>>>> ts/ >>>>> >>>>> The datasheet for the 6526 shows PA and PB with exactly the same source >>>>> current (and other electrical characteristics). >>>>> >>>>> Looking at the actual silicon die I didn't notice any difference either, >>>>> hrm. Maybe I missed something. >>>>> >>>>> Or those test programs are seeing the effect of the keyboard circuitry? >>>> >>>> there is no "circuitry" in the keyboard, other than wires and switches :) >>> >>> Yes, so a lot of resistance and capacitance :-) >> >> sure, but the exact same thing connecting different ports makes a >> difference... if the the ports would be exactly alike, it wouldnt matter :) > > 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. GerritReceived on 2018-06-10 19:00:04
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