Tommy Sprinkle / MVS 3.8
Utility programs for classic MVS systems

MVS Utilities / DABR

Dataset Browser

DABR examines the physical blocks of a dataset on DASD using EXCP and the Read Track channel command.

DABR Dataset Browser entry screen showing Dataset and VOLSER fields
DABR dataset and volume selection screen.

Browsing a Dataset

The Dataset Browser utility displays physical blocks of a dataset on a DASD device. It uses EXCP and the Read Track channel command code to read the data. DABR displays the DASD blocks themselves rather than interpreting the contents as logical records.

To browse a dataset, the dataset must be cataloged. For an ordinary cataloged dataset, the VOLSER field is ignored.

Browsing a VTOC

To browse a Volume Table of Contents, enter VTOC as the Dataset name and specify the volume serial in the VOLSER field. In this case the VOLSER identifies the DASD volume whose VTOC is to be read.

DABR Dataset Browser displaying a physical DASD block in hexadecimal and character form
A physical DASD block displayed by DABR.

Block Information

In addition to the block contents, the display identifies the physical and relative location of the block and the lengths of its key and data portions.

TTR
The relative Track-Record address of the block being displayed.
Show Key
Indicates whether the key portion of the block should be displayed when key data is present.
Key
Length of the key portion of the block, in decimal.
Data
Length of the data portion of the block, in decimal.
CCHHR
The actual Cylinder-Head-Record address of the physical block.

PF Keys

PF KeyFunction
PF3 / PF15End — return to the previous screen.
PF4 / PF16Exit — exit the Browse utility.
PF7 / PF19Scroll up.
PF8 / PF20Scroll down.
PF10 / PF22Display the previous record.
PF11 / PF23Display the next record.

Downloads

Source code and the MVS load modules for DABR and the other MVS utilities are available from the utility downloads page.

MVS Utility Downloads