Hi Dave, the pinout of the Q40/Q60 extension slot and the signal polarities are exactly ISA.
8 interrupt lines, see hardware doc PDF. Software-programmable slot RESET, see hardware doc PDF. Unused (or just correctly terminated) are: -5V, DMA signals, REF, CLK, TC, OSC, IOCHK, IORDY, LA20..23, MEMCS16, IOCS16 Pure Q40/Q60 extensions can simply be designed using: MEMW, MEMR, IOW, IOR, SBHE, ALE, RESET, adress/data lines, interrupt lines and supply voltages. No need to deal with PC bus multiplexing related issues or some critical ISA timing definitions. If you use modern chips (CS8900 and probably all the ones used by Nasta) there should be no need to deal with bus timings at all. If you decide to actually do a design, I can provide you with mainboard schematics. For ISA definitions, please use your favorite English PC hardware books ;-) (I only have German ones.) Peter
