On Fri, 19 Mar 1999, Grant Stockly wrote:

> I'm having trouble getting the timeing down correctly for the PC XT/AT
> Keyboard and Mouse driver.
> 
> What this device does is connects to the internals of your computer and
> gives you the opportunity to use XT/AT input devices on your mac.
> 
> I'm having trouble getting the ADB timings down.  I know its an open
> collector interface, but thats not too much to go by.
> 
> If anyone has any information about the ADB internals I'd appreatiate some
> help here.  I'd also like to know if anyone is aware of a block of
> addresses on the NuBUS that aren't used in all computers.

For ADB, check out Inside Macintosh. Volume 5 (old IM) had it, as does the
Devices volume (I think).

As for NuBus, it's different from ISA. Each NuBus card is assigned a
chunck of the address space, based on its slot. For instance, in a Mac
IIci, any card in slot C has a full meg assigned to it in 24-bit
addressing, and a full 256 MB in 32-bit addressing. In 24-bit addressing,
it's at 0xc00000->0xcfffff. It doesn't matter what card it is, it's in the
same place in the address space.

Don't try and pick addresses which aren't in use. Just use your assigned
space. :-)

> This could be done on the ATA-4 drive card, but then people couldn't use
> the keyboard and mouse in windows.

??

Take care,

Bill