On Nov 19, 2017 7:18 PM, "allison via cctalk" <cctalk@classiccmp.org> wrote:
The rest is the specific implementation. What happens if the CPU is 1802 or something else that does not match the 6500 or 8080z80 models. There is nothing that prevents either the serial or parallel arbitration schemes from working with other processors. In the case of the 1802, it would work easily for interrupts, but would need some additional circuitry for DMA, because the 1802 doesn't include any feature whereby another bus master can request that the 1802 surrender control of the bus. Instead, the 1802 has a built-in single-channel DMA controller. That 1802 bus master problem exists for interfacing _any_ sort of bus master to any 1802, and is totally independent of what kind of DMA arbitration is chosen.