Commodore 128 Programmer's Reference Manual page 450

440 COMMODORE 128
RESULTS:
Registers:
Memory:
Flags:
EXAMPLE:
SEI
JSR $FFEA
CLI
.A used
.X used
TIME, TIMER, STKEY updated
none
;UDTIM
0
u
u
UDTIM increments the system software (jiffie) clock, which counts sixtieths
(1/60) of a second when called by the system 60Hz IRQ. TIME, a 3-byte counter ) i
located at $A0, is reset at the 24-hour point. UDTIM also decrements TIMER, also jj
a 3-byte counter, located at $A1D (BASIC uses this for the SLEEP command, for
example). You should be sure IRQ's are disabled before calling UDTIM to prevent v ,
system calls to UDTIM while you are modifying TIME and TIMER. jj
UDTIM also scans key line C7, on which the STOP key lies, and stores the
result in STKEY ($91). The Kernal routine STOP utilizes this variable.
37. $FFED SCRORG ;get current screen window size
PREPARATION:
Registers:
Memory:
Flags:
Calls:
RESULTS:
Registers:
Memory:
Flags:
EXAMPLE:
JSR $FFED
none
system map
none
none
.A = screen width
.X = window width
.Y = window height
none
none
:SCRORG
l l /
SCRORG is an Editor routine that has been slightly changed from previous
CBM systems. Instead of returning the maximum SCREEN dimensions in .X and J {
.Y, the C128 SCRORG returns the current WINDOW dimensions. It does return U
the maximum SCREEN width in .A. These changes make it possible for applica
tions to "fit" themselves on the current screen window. SCRORG is also an Editor ( i
jump table entry ($C00F). jj