Re: trump card disk card 0(zero) kb
Posted: Thu Sep 02, 2021 9:40 pm
o12 is your DSMCL line - DataStrobeMasterChip - it will disable internal devices that would otherwise be selected by the partial address decoding in the standard QL.
The equation is built from several lines - each of which is atually the selection of I/O devices, RAM or ROM on the trump card. See if you can work out what you need based on the information already in the thread here.
Some hints - you don't need to do the address relocation trick for ROM - so you already have one of your equation lines (these lines are all linked by + (for OR))
You don't need to or want to assert DSMCL for any RAM address decoding on the trump card - you don't have any - so look for one line that clearly is there to assert DSMCL when expansion memory is selected.
The other 2 lines you should need are for when the disk controller or 175 latch are operated - if you know the address of these - you can work out the address selection.
Finally - as regards ROM - you can use any of the ROM images - the choice depends somewhat on what you are looking for.
The equation is built from several lines - each of which is atually the selection of I/O devices, RAM or ROM on the trump card. See if you can work out what you need based on the information already in the thread here.
Some hints - you don't need to do the address relocation trick for ROM - so you already have one of your equation lines (these lines are all linked by + (for OR))
You don't need to or want to assert DSMCL for any RAM address decoding on the trump card - you don't have any - so look for one line that clearly is there to assert DSMCL when expansion memory is selected.
The other 2 lines you should need are for when the disk controller or 175 latch are operated - if you know the address of these - you can work out the address selection.
Finally - as regards ROM - you can use any of the ROM images - the choice depends somewhat on what you are looking for.