PRINT USR 5631, which registers are free to use during USR?
Posted: Mon Jun 10, 2019 2:51 pm
As can be seen from https://skoolkit.ca/disassemblies/rom/asm/5615.html this simply performs a
in the original 48K-ROM and does all kinds of strange things.
https://skoolkit.ca/disassemblies/rom/asm/13491.html warns "For a successful return to BASIC, HL' must on exit from the machine code contain the address of the 'end-calc' instruction at 10072." Is this all there is to know? Do other registers as HL' and SP also need to be considered?
Code: Select all
EXX
REThttps://skoolkit.ca/disassemblies/rom/asm/13491.html warns "For a successful return to BASIC, HL' must on exit from the machine code contain the address of the 'end-calc' instruction at 10072." Is this all there is to know? Do other registers as HL' and SP also need to be considered?