DISPLAY (Host Storage)

Read syntax diagramSkip visual syntax diagram Display H1 LRNIKSUXTXMX0hexloc1%&-:ENDhexloc2.ENDbytecount
Notes:
  • 1 Do not put blanks between operands that relate to a single DISPLAY request.

Authorization

Privilege Class: C, E

Purpose

Use DISPLAY (Host Storage) to see the contents of host (first-level) storage.

Operands

L
specifies that host logical storage addresses are to be displayed. Host logical storage consists of 4 KB pages where each page boundary has an address that ends in X'000'. This is the default.
R
specifies that host real storage addresses are to be displayed. Host real storage consists of 4 KB frames where each frame boundary has an address that ends in X'000'.
N
displays the contents of storage in hexadecimal without character translation. This is the default. Storage is displayed in word segments. An address range is displayed starting at the fullword in which the specified address resides. Storage is displayed in fullword increments.

The storage key is included on the first line and at every page or frame boundary.

I
displays the contents of storage in instruction format. The specified address is rounded down to the nearest halfword boundary.

The storage key is included on the first line and at every page or frame boundary.

K
displays in hexadecimal the storage keys for all frames or partial frames included in the specified address range. If you are displaying host logical storage addresses, these are storage keys for the backing frames in host real storage.
S
displays the contents of storage in hexadecimal translation. Storage is displayed as a string starting at the location specified. The specified address range is not boundary-aligned.

The storage key is included on the first line and at every page or frame boundary.

T
displays the contents of storage in hexadecimal and character form. Storage is displayed in word segments. An address range is displayed starting at the X'10'-byte boundary in which the specified address resides. X'10' bytes of storage are displayed per line. The default display is in EBCDIC; the display is in ASCII if the X option is specified.

The storage key is included on the first line and at every page or frame boundary.

U
displays the contents of storage in character form. Storage is displayed starting at the address specified as an EBCDIC string or as an ASCII string if the X option is specified. The specified address range is not boundary-aligned.

The storage key is included on the first line and at every page or frame boundary.

M
displays the contents of storage in hexadecimal and character form. A header is included as the first line and at every page or frame boundary. It contains the high-order 32 bits of the 64-bit address along with the storage key. Storage is displayed in word segments. An address range is displayed starting at the X'10' byte boundary in which the specified address resides. X'10' bytes of storage are displayed per line. The hexadecimal display is followed by the storage as an EBCDIC string, or as an ASCII string if the X option is specified.
0
hexloc1
is the starting storage location that is to be displayed. The address hexloc1 may be 1 to 16 hexadecimal digits, separated with an optional underscore for readability; leading zeros are optional. The default is zero.
Storage locations and the minimum amount displayed are rounded according to the following conventions (in hexadecimal):
Option Start Minimum Length
T 10 10
M 10 10
K 800 800
S 1 1
I 2 2 - 6 depending on the instruction
N 4 4
U 1 1
%
indicates 31-bit address indirection. Indirection means that the contents of the specified address are used instead of the address itself. In this case, the 31 bits at the specified address (the high-order bit is turned off) are used as the new address for the DISPLAY command.
&
indicates 64-bit address indirection. Indirection means that the contents of the specified address are used instead of the address itself. In this case, the 64 bits at the specified address are used as the new address for the DISPLAY command.
-hexloc2
:hexloc2
-END
:END
is the last of the range of hexadecimal storage locations whose contents are to be displayed. If specified, hexloc2 must be equal to or greater than hexloc1 and must be within the bounds of addressable storage (see usage note 3). The address hexloc2 may be from 1 to 16 hexadecimal digits, separated with an optional underscore for readability; leading zeros are optional. A colon (:) means the same as a dash (-) when you are specifying a range of addresses.

Specify END if you want to display the remaining contents of storage. END is the default if you specify a dash (-) or a colon (:) without an address.

.bytecount
.END
is a hexadecimal integer designating the number of bytes of storage (starting with the byte at hexloc1) to be displayed. If specified, the bytecount must have a value of at least 1 and may be from 1 to 16 hexadecimal digits, separated with an optional underscore for readability; leading zeros are optional. The sum of hexloc1 and bytecount must be an address within the bounds of addressable storage (see usage note 3).

Specify END if you want to display the remaining contents of storage. END is the default if you specify a period (.) without a byte count value.

Usage Notes

  1. While host storage is being displayed, the running of a virtual machine or someone else using the STORE (Host Storage) command could cause data to be changed. This could create an inconsistency in the data that is viewed.
  2. In a multiprocessor environment, each processor has a prefix register that it uses to relocate addresses between 0 and X'1FFF' (an 8 KB area known as the prefix area) to two other contiguous frames in real storage. The prefix register enables each processor to use a different prefix area to avoid conflict with other processors for such activity as interrupt code recording. Thus, the range 0 through X'1FFF' refers to different areas of storage, depending on which processor generates the address. All references to first-level storage are handled as if they were made on the IPL processor. Because those locations in the system execution space are identity-mapped, addresses in the range 0 through X'1FFF' have the same content in DISPLAY HL output and DISPLAY HR output.
  3. For host logical storage (the system execution space), addressable storage includes the system execution area, which resides below 2 GB, plus the system frame table and the system execution space page management table, which reside above 2 GB. To display the storage address ranges used for the system execution space, issue the QUERY SXSSTORAGE command. The address range that you specify on the DISPLAY command must start and end in the same address range of the system execution space. If the END operand is specified (or allowed to default), it refers to the end of the range in which the starting address is located.

    For host real storage, addressable storage is the lesser of CP's configured storage size (if specified at system generation) and the real machine storage size. To display the size of host real storage, issue the QUERY STORAGE command.

  4. When displaying host logical storage, if you specify an address that is not backed with a real storage frame, error message HCP6151E is issued, even if the address is included in the ranges of in-use and usable addresses displayed by the QUERY SXSSTORAGE command.
  5. If you use an underscore, it must be followed by 8 hexadecimal digits.
  6. For more information, see Usage Notes.

Responses

Notes:
  1. The variable hexloc represents a hexadecimal storage address. The variables hexlochi and hexloclo represent the high-order 32 bits and low-order 32 bits of a 64-bit hexadecimal storage address.
  2. The character displayed for the variable t in the string Hthexloc indicates the type of storage:
    • L indicates host logical storage.
    • R indicates host real storage.
  3. In responses that include host logical storage, an Rhexloc trailer shows the host real storage address that corresponds to the host logical storage address. The trailer is displayed on the first line of a range and at every page boundary.
Response 1:
Hthexloc word1 word2 word3 word4 [key] [*TRANSLATION*] [Rhexloc]
is the response you receive for the T or N option. The translation is displayed only if you have also entered the T option and is in either EBCDIC or (if the TX option is specified) ASCII. The storage key is displayed on the first line, and at every page or frame boundary.
Response 2:
Hthexlochi_ Storage Key - [key]
 hexloclo word1 word2 word3 word4 [*TRANSLATION*] [Rhexloc]
is the response you receive for the M option. The translation is displayed in either EBCDIC or (if the MX option is specified) ASCII. The storage key is displayed on the first line, and at every page or frame boundary.
Response 3:
Hthexloc *TRANSLATION* [key] [Rhexloc]
is the response you receive for the U option. The value hexloc is the location of the first data byte to be displayed. A minimum of 1 character and a maximum of 32 characters is displayed on each line. The contents of storage are displayed in translated form and are in either EBCDIC or (if the UX option is specified) ASCII. Periods in the display data represent unprintable characters. The storage key is displayed on the first line, and at every page or frame boundary.
Response 4:
Hthexloc mnemonic x-x mnemonic x-x mnemonic x-x [key] [Rhexloc]
is the response you receive for the I option. The value hexloc is the location of the first instruction to be displayed. The value mnemonic is a character representation of the instruction code; this is a 7-character field in which the mnemonic is left-justified. The expression x-x is the actual hexadecimal contents of storage and is 2, 4, or 6 bytes as determined by the instruction length code. Unrecognizable instruction codes are indicated by a series of asterisks. A minimum of 1 instruction and a maximum of 3 instructions are displayed on each line. The storage key is displayed on the first line and at every page or frame boundary.
Response 5:
Hthexloc stringhexadecimaldata [key] [Rhexloc]
is the response you receive for the S option. The storage key is displayed on the first line of a range, and at every page or frame boundary.
Response 6:
Hthexloc1 TO hexloc2 KEY = key
is the response you receive for the K option. The values hexloc1 and hexloc2 are storage locations, and key is the associated storage key for hexloc1. You receive this response for every contiguous address range that has unique storage keys, and whenever a segment boundary is crossed.

Response 7:

If your display request includes a request to display one or more lines identical with the previous line, you receive the following response:
Hthexloc1 TO hexloc2 SUPPRESSED LINE(S) SAME AS ABOVE …