[net.micro.atari] ACTION! and DOS XL

cel@CIT-HEX.ARPA (01/15/86)

On the subject of bank switching in the supercartridges, does anyone
know the software proceedure for getting the cartridge to swap?
Perhaps writing to a particular address in the cartridge address
space?  

striepe@muscat.UUCP (Harald Striepe) (01/17/86)

> 
> On the subject of bank switching in the supercartridges, does anyone
> know the software proceedure for getting the cartridge to swap?
> Perhaps writing to a particular address in the cartridge address
> space?  

The "SuperCartridges" make use of the CARTSEL (?) line at $D500.

Typically,  the lower 4K of cart space are switched ($A000-$AFFF).

Location $AFFF contains the current bank number (I think....).

To switch,  simply load the bank number in X,  and store the accumulator
at $D500 X indexed.

Bank 8 switches out the complete cart to make RAM available (all 8K).
Selecting any valid bank restores the cart.

e.g.:	select bank 0

	LDX #0
	STA $D500,X

	select RAM

	LDX #8
	STA $D500,X
Dont't forget to worry about the display location and OS database when
making the cart appear and disappear....



-- 
Harald Striepe
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