Hi John,
No, you don't need to preserve them. After a CALL operation, the "OS"
does a "RET" operation to an address it PUSHed to the stack. The routine
at that address does not depend on any partiular value in any of the
registers.
Ken
On 11/7/22 11:44 AM, John R. Hogerhuis wrote:
Are CALL subroutines required to preserve any registers?
HL and A hold incoming parameters. So presumably they're fair game for
changing without restoring.
The question is about BC and DE. Can those be modified without
restoring them?
-- John.
