Index

Function Name: SETTMO

Purpose: Set IEEE bus card timeout flag
Call address: $FFA2 (hex) 65442 (decimal)
Communication registers: A
Preparatory routines: None
Error returns: None
Stack requirements: 2
Registers affected: None

NOTE: This routine is used ONLY with an IEEE add-on card!

Description: This routine sets the timeout flag for the IEEE bus. When the timeout flag is set, the Commodore 64 will wait for a device on the IEEE port for 64 milliseconds. If the device does not respond to the Commodore 64's Data Address Valid (DAV) signal within that time the Commodore 64 will recognize an error condition and leave the handshake sequence. When this routine is called when the accumulator contains a 0 in bit 7, timeouts are enabled. A 1 in bit 7 will disable the timeouts.

NOTE: The Commodore 64 uses the timeout feature to communicate that a disk file is not found on an attempt to OPEN a file only with an IEEE card.

How to Use:

TO SET THE TIMEOUT FLAG

  1. Set bit 7 of the accumulator to 0.
  2. Call this routine.

TO RESET THE TIMEOUT FLAG
  1. Set bit 7 of the accumulator to 1.
  2. Call this routine.

EXAMPLE: 

   ;DISABLE TIMEOUT
   LDA #0
   JSR SETTMO