Register contents when Exit 48 gets control

The contents of the registers on entry to this exit are:

Register

Contents

0

1

Pointer to a 24-byte parameter list with the following structure:

Byte 1 (+0)

Type of data set indicator

Byte 2 (+1)

This byte is not part of the programming interface.

Byte 3 (+2)

Response byte

bits 0-6: These bits are not part of the programming interface
bit 7: 0 – Do not spin the data set.
1 – Spin the data set. For more information, see Programming considerations

Byte 4 (+3)

This byte is not part of the programming interface

Byte 5 (+4)

SDB address.

Byte 9 (+8)

SJB address.

Byte 13 (+12)

JFCB address.

Byte 17 (+16)

PDDB address.

Byte 21 (+20)

IOT address

2-10

N/A

11

Address of HCCT

12

N/A

13

Address of the register save area

14

The return address

15

The entry point address