On 06/10/2018 07:00 PM, Michał Pleban wrote: > Gerrit Heitsch wrote: > >> Another Idea would be to use an AM2130 (datasheet is available online) >> or similiar chip instead if you can find them. That's a 1k x 8 dualport >> RAM with built in arbitration. Should be perfect to interface 2 systems. > > That sounds like a cool chip! It is... It can even produce IRQs when writing to $3FE / $3FF (depending on side), alerting the other side that data is waiting. The 'Kronos' SCSI-Controller for the Amiga used 2 of them. > But a problem here is that the 6509 interface routines are placed in the > KERNAL. So the card should be compatible with the existing hardware > which uses 6526. The routines could be rewritten and placed in RAM, but > then the original MS-DOS will not work with the new card. Hm, OK... Looks like a CPLD imitating the 6525/6526 pair then. GerritReceived on 2018-06-10 20:00:30
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