IBM System/370 145 Operating Procedures Manual page 38

NOTE
When the operation is ended with the ALTER/DISPLAY
key, the PR-KB remains in alter/display mode (AL TER/
DISPLAY MODE indicator on).
When the operation is terminated with the END key,
alter/display mode is terminated.
For alter/display of general-purpose and floating-point
registers, a wraparound is performed (F to 0 for GP
registers, and 6 to 0 for floating-point registers).
When addressing main storage, either a word or byte
address may be used. I f the starting address is not on a
word boundary, the PR-KB spaces and aligns at the byte
addressed.
Alter/Display Examples
In the following examples, the X's represent digits dis-
played or entered and printed by the PR-KB.
MAIN STORAGE
DM 000080
XXXXXX XXXXXXXX XXXXXXXX----------XX
XXXXXXXX XXXXXXXX (Press the ALTER/DISPLAY
or END key)
DM 8D (Press the RETURN key)
XXXXXX XXXXXXXX XXXXXXXX---------·XX
XXXXXXXX XXXXXXXX (Press the ALTER/DISPLAY
or END key)
AM 480 (Press the RETURN key)
XXXXXXXX XXXX (Press the AL TER/D ISPLA Y or
END key)
FLOATING-POINT REGISTER
OF 2
XXXXXXXX XXXXXXXX XXXXXXXX-·····-···XX
STORAGE KEY
OK 009000
XXXXXXXX XXXXXXXX XXXXXXXX (Press the
ALTER/DISPLAY or END key)
Each word contains four storage keys.
CURRENT PSW
AP
XXXXXXXX XXXXXXXX
The current PSW is not altered until a doubleword is typed.
Alter/Display Error Messages
INVAL CHAR
Prints when one of the following errors occurs.
1. The first character of a mnemonic is not A or D.
2. The second character is not M, S, L, K, C, G, F, or P.
S, L, and C are used by service personnel.
3. An invalid digit is typed when addressing or altering
data.
4. The CANCEL key is pressed.
INVAL ADDR
Prints when one of the following errors occurs.
1. I nvalid starting address.
2. The updated address exceeds the capacity of specified
storage.
Operating Procedures 37