Purpose: Control system message output
Call address: $FF90 (hex) 65424 (decimal)
Communication registers: A
Preparatory routines: None
Error returns: None
Stack requirements: 2
Registers affected: A
Description: This routine controls the printing of error and control messages by the KERNAL. Either print error messages or print control mes- sages can be selected by setting the accumulator when the routine is called. FILE NOT FOUND is an example of an error message. PRESS PLAY ON CASSETTE is an example of a control message.
Bits 6 and 7 of this value determine where the message will come from. If bit 7 is 1, one of the error messages from the KERNAL is printed. If bit 6 is set, control messages are printed.
How to Use:
LDA #$40 JSR SETMSG ;TURN ON CONTROL MESSAGES LDA #$80 JSR SETMSG ;TURN ON ERROR MESSAGES LDA #0 JSR SETMSG ;TURN OFF ALL KERNAL MESSAGES