; The Z80 CPU can directly access 64K of memory between $0000-$FFFF.
; The TS1500 ROM resides between $0000-$1FFF.
; The TS1500 RAM resides between $4000-$7FFF.
; By default, $2000-$3FFF and $8000-$FFFF are not populated with ROM or RAM.
; Machine code cannot be executed between $8000-$FFFF, but data may be held here.
;
; A Command Cartridge can be 8K, 16K or 24K in size.
; If 8K then the ROM of the Command Cartridge appears between $2000-$3FFF.
; If 16K then the ROM of the Command Cartridge appears between $2000-$3FFF and $8000-$9FFF.
; If 24K then the ROM of the Command Cartridge appears between $2000-$3FFF and $8000-$BFFF.
;
; At power on, the TS1500 ROM checks the byte at location $2000. If it holds $01 then the contents of the Command Cartridge are executed from $2000.
; With no Command Cartridge connected then the value read from $2000 would be $FF.