Tandy 600 Programmer's Reference Manual page 158

INT
54h,
Function 3
-
Set Current
Time
Entry:
AH =
3 (function
code)
CH =
hours
(0
through
23)
CL =
minutes
(0
through
59)
DH
=
seconds
(0
through
59)
DL-
hundredths
of
seconds
(0
through
99)
Exit:
AL =
return
code
-
no
errors
FF
- invalid
time,
operation aborted
INT 54h,
Function 4
-
Get Alarm Date
Entry:
AH =4
(function
code)
Exit:
AL=day
of
week
(0
=
Sun,
1=Mon
6
=
Sat)
CX =
year (1980
through 2099)
DH =
month
(1
through
12)
DL =
day
(1
through
31)
INT 54h,
Function 5
-
Set
Alarm Date
Entry:
AH
=
5 (function
code)
CX=year
(1980 through 2099)
DH =
month
(1
through
12)
DL
=
day
(1
through
31)
Exit:
AL =
return
code
-
no
errors
FF
-
invalid
date,
operation aborted
INT
54h,
Function 6
-
Get Alarm Time
Entry:
AH =
6
(function
code)
Exit:
CH =
hours
(0
through 23)
CL =
minutes
(0
through
59)
DH
=
seconds
(0
through
59)
DL=
hundredths
of
seconds
(0
through
99)
INT 54h, Function
7
-
Set
Alarm
Time
Entry:
AH
=
7
(function
code)
CH
=
hours
(0
through
23)
CL
=
minutes
(0
through
59)
DH
=
seconds
(0
through
59)
DL=
hundredths
of
seconds
(0
through 99)
Exit:
AL=
return
code
-
no
errors
FF
- invalid time,
operation aborted
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