ZiLOG Z80-RIO Operating System User's Manual page 211

APPENDIX F
I/O REQUEST VECTOR FORMAT
and
I/O REQUEST CODES
I/O Request Vector Format
Byte
o
1
2-3
4-5
6-7
8-9
A
B-C
Contents
Logical Unit Number
Request Code
Data Transfer Address
Data Length
Completion Address
Error Return Address
Completion Code
Supplemental Parameter
Vector Address
ZDOS/DFS Supplemental Parameter Vector
o
1
2
3
I/O Request Codes
o
2
4
6
8
A
Flag Byte (ASSIGN),
Open Type (OPEN)
Drive Designation
File Name Length
File Name
Initialize
Assign
Open
Close
Rewind
Read Binary
F-l