Tandy 1000 SL Technical Reference Manual page 549

Software
Read Clock Time of Day
Read the time of day kept in the clock.
Entry Conditions
AH
=
2
Exit Conditions
CH
=
hoursinBCD
CL
=
minutesinBCD
DH
=
secondsinBCD
Set Clock Time of Day
Set the time of day kept in the clock.
Entry Conditions
AH
=
3
CH
=
hoursinBCD
CL
=
minutesin BCD
DH
=
secondsinBCD
28.