On 2014-06-09 at 13:02:45, Gerrit Heitsch (gerrit@laosinh.s.bawue.de) wrote: > Hello, > > has anyone here ever done a ROM dump of the keyboard controller of the > Amiga? > > The controller is, on most Amigas, a 6570-036. This one looks a lot like > the 6500/1 Microcontroller MOS offered back then. It's, of course, based > on the 6502 that's why I thought it appropriate to ask here. I asked some time ago too ;-) Besides - Amiga was built bytoo.. > Datasheet here: > > http://www.6502.org/documents/datasheets/mos/mos_6500-1_one-chip_microcomputer_oct_1986.pdf > > This Microcontroller has a test feature where you supply +10V to the > RESET pin and from then on all memory fetches happen not from the > internal ROM but from Port PC. According to the datasheet this will > allow you to load a small program into the internal RAM (64 Bytes) that > can, once RESET returns to +5V, dump the ROM to another port. > > Anyone here ever built such a circuit? Writing the program would be > interesting since you have no address lines but only have to make sure > that the correct byte is present on Port PC in the next cycle (external > clock is divided by 2). Tinkering with 6500/1 is already long on my list and we discussed it here some time ago but I never came to it so far. One of the reasons being the relative uncertainty of how this can actually be done. AFAIR the datasheet was far from being clear and unambiguous on that. But yes - I am still very much interested. Not only because of the Amiga keyboard but also because of the 1520 ROM, which I want to put my fingers on for a long time! -- SD! Message was sent through the cbm-hackers mailing listReceived on 2014-06-09 13:00:02
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