.TITLE LTSH / / 8 MAR 72 - MOD BY P. HENDERSON / .GLOBL LTSH,%START,%STOP,%ENTER / /LOAD TIMER ONCE AND SET HANDLER SUBROUTINE /EXECUTION TIME: 81 TO 96 MICROSECONDS /CALLING SEQUENCE: CALL LTSH(TIME,HANDLER,ERROR) / TIME: POSITIVE INTEGER CLOCK INTERVAL / (IN UNITS OF 16 2/3 MILLISECONDS) / HANDLER: PARAMETERLESS FORTRAN IV SUBROUTINE NAME / (CLOCK INTERRUPT HANDLER) / ERROR=0: NO ERROR / =1: TIME NOT > 0 / LTSH XX .ARG LTSH DAC TIME /INTERVAL LOCATION .ARG DAC HANDLER /USER SUBROUTINE .ARG DAC ERROR DZM* ERROR /ERROR=0 LAC* TIME SPA!SNA JMP ERROR1 /TIME NOT > 0 JMS* %START /START THE CLOCK LAC* TIME /DESIRED INTERVAL JMS* %ENTER /NOTIFICATION REQUEST CLOCK JMP* LTSH CLOCK 0 JMS* %STOP /STOP THE CLOCK JMS* HANDLER /GO TO USER JMP* CLOCK ERROR1 ISZ* ERROR /ILLEGAL TIME REQUESTED JMP* LTSH TIME HANDLER ERROR .END