Hallo PD, > Is the hardware configured to ROML/ROMH/IO by the > RESET signal or does is depend strictly on IOINIT to > configure it that way? A RESET puts the onboard port in input mode. Some resistors pull the lines (H). During IOINIT the 6510 programs pins as (H) and as output. AFAIK in that order. > The hardware that controls the banking function is in > the PLA right? I.E. R6510 is strictly a bi-directional > I/O register and the banking logic is external to the > 6510, right? Banking is setting a register which on the end enables a different part of the memory. So IMHO the 6510 and PLA are both a part of the banking system. The PLA is nothing more then a bunch of gates, _NO_ flipflops, and does nothing more then a kind of translation: a certain code on the input lines leads to a certain code on the outputlines. You could say that the 81S100-PLA is nothing more then a very fast ROM. Groetjes, Ruud http://Ruud.C64.org/ - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail email@example.com.
Archive generated by hypermail 2.1.1.