ZiLOG Z80-RIO Operating System User's Manual page 157

6.8
WRITE CURRENT
WRITE CURRENT
Request vector:
Logical unit
Request code - 12 or 13
Data transfer area - the address from which data is
to be transferred.
Length - if the length is zero, no data will be
transferred. Otherwise, one record will be
transferred. On return, length will contain
the number of bytes transferred.
Completion return address
Error return address
Completion code
Supplemental parameter information - if the unit is
open for random I/O, this field should
Actio~:
contain the address of a three-byte area
where the disk address of the record will
be returned. Otherwise, it is unused.
Data is moved from memory to the file,
replacing the data in the current record. No
new records are created, and the record
pointer is not moved.
Possible errors:
All DISK ERRORs except CRC (code C6) are
possible. PROTECTION (code C3) will also be
returned by ZDOS if the file is write
protected.
FILE NOT OPEN (code CB) - the logical unit
being accessed is not active. No action is
taken.
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