Radio Shack TRS-80 Model II Reference Manual page 215

Technical Information
Exit Conditions
NZ
=
Error
A
=
Error Code
Upon return, your record is in the Record Area pointed to by RECADR in
the parameter list, or, if RL=256 and record type is Fixed, your record is in
the area pointed to by
BUFADR.
DIRRD
Direct Read (function code 35)
This routine reads the specified record, allowing direct access.
Note: With
VLR
files, you can only use it to read the first record or to read the
end of file.
Entry Conditions
(DE)
=
Data Control Block for currently Open file (see
OPEN)
BC
=
Desired record number
BC
=
0 means position to beginning of file
BC
=
X'FFFF'
means position to end of file
HL=
A=
Reserved for use in later versions of
TRSDOS
35
Exit Conditions
NZ
=
Error
A
=
Error Code
Upon return, your record will be in the Record Area pointed to by RECADR
in the parameter list, or, if RL = 256 and record type is Fixed, your record is in the
area pointed to by
BUFADR.
251