On Wed, 5 Dec 2001, Eric Boon wrote: > > This would appear to be the register at memory location #FFFF in slot 3. > > Almost right - It *is* the register at #FFFF, but since > it's used to select a sub-slot, you can't really say that it's > in slot 3. It's not memory, it's omni-present ;-)
It's accessed using MREQ# rather than IORQ#. Are you saying you don't have to select slot 3 in order to change it? In which case, does it affect other expanded slots also? ie. is it possible to have more than one secondary slot register, on a per slot basis, or does writing to the same register affect all slots? Presumably when the RAM at #C000 - #FFFF is enabled, writing to this register will also "write through" to the RAM at location #FFFF, so that reading from this location will return the last value written to the register. (?) Richard -- For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
