Radio Shack TRS-80 Model II Reference Manual page 184

MODEL II TRSDOS
Supervisor Calls
In this section we will use the following notation:
NOTATION
RP
=
data
n1 < R< n2
(RP) = data
NZ
=
Error
MEANING
The register-pair RP contains the data.
The register R contains a value greater than n1
and less than n2
The register-pair RP contains the address of
("points to") the data.
If Z flag is not set, an error occurred.
When a range is not given, any representable number can be used. For
example, a register can contain any value from 0-255.
The contents of this section are:
System Control Supervisor Calls 4/15
Keyboard Supervisor Calls 4/27
Video Display Supervisor Calls 4/31
Line Printer Supervisor Calls 4/45
File Access Supervisor Calls 4/49
Computational Supervisor Calls 4/61
Serial Communications Supervisor Calls 4/75
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