The 1BCDASD1 program can assign
alternate tracks for real 3330/3340/3350 volumes only when they are specified by
the GETALT statement. Even with the
GETALT statement, the 1BCDASD1 program cannot assign alternate tracks for a 3330/3340/3350 minidisk because no
cylinder has been allocated on which to
assign alternate tracks. Defective
tracks are flagged and alternate tracks
are assigned when the 3330/3340/3350 storage volumes are initialized at the
factory. An 1BCDASD1 job that
initializes a 3330/3340/3350 performs
the "Quick DASD1" function, which reads
alternate tracks, decrementing the total
unit of alternates by one whenever an
alternate is found defective or
assigned, writes a volume label and VTOC, and writes an 1PLTEXT if requested. No surface analysis is
performed and no home address or record
o is written on the primary tracks. The BYPASS and FLAGTEST options of the DIDEF statement are ignored. DASD 3340 disk packs are factory-shipped
without flagged tracks and alternate track
assignments. 1BCDASD1's "Quick DASD1" detects 3340 customer-generated alternate track assignments.
The IBCDASD1 program cannot check to see
if the 3330, 3340, or 3350 space to be
initialized was previously formatted.
The absolute loader gives control to the START routine. After the control
statements are read and analyzed,
control is passed to: VOLCHK GENSE
if volume label checking and
virtual disk initialization are
requested.
if virtual disk initialization
without volume label checking
is requested. GETALTYZ if alternate track assignment
is requested. OPRTAB A list of valid command words
used on control cards. 10 IBM VM/370 Service Routines Program Logic KEYTAB A list of valid key words used
on control cards. SY1NTAB A list of valid input devices
for control cards. DEVTAB A list of valid devices handled
by the IBCD1SDI program. PROCBUFF 1 list of constants for specific device types. COBVTIB I tatle used to convert console
input to upper case. IOTAE I tatle used to convert hexadecimal to EBCDIC graphic.
ALTTT I tatle used to convert EECtIC graphic to hexadecimal. TIB13 TABS! A buffer of hexadecimal zeros (X'OO') for disk and drum
surface analysis. A buffer of hexadecimal E5s (X'ES') for data cell surface
analysis. Also used as a
buffer of hexadecimal 55s (X' 55') for disk and drum surface analysis. None
External References ---The-program-enters an enabled wait state
shortly after it is loaded. An attention interrupt identifies the
virtual machine console and the INPUT control statement is read. This control statement tells IBCDASDI which device to
read to get the program control
statellents.
Exit Conditions ---Successful-completion of DMKMDA results
in a wait PSi with E's in the address
field. An end of job lIessage is also
given on the message device.
Error exits result in E's being loaded
in the address field of a wait PSi. Error stops, whenever possible, are preceded by a message which defines the
error. Machine check interrupts result
in the loading of a PSi in the wait
state with E2 in the address field.
Directory
Figure 1-2 is an alphabetical list of some
of the labels in the IBCDASDI module. The
function performed at the point in the
program indicated ty each label is
described and the asseciated method ef
operation diagram is referenced. Label Diagram ABCFOUND 1 ... 1
ASGNALT 1-3 CKINPUT 1-1 CJ,RSCAN 1-1 CONSTR2 1-2 DASDI 1-1 FMTVTOC 1-2
GENSE 1-1 GETALTX 1-3 GETALTYZ 1-1
GETALT2 1-3
GETALT4 1-3
INTALT 1-2 START 1-1 TRKPRNT 1-3 VOLCHK 1-1 WRTIPL 1-2 WRTVTOC 1-2
Description
Finds size of alternate track area.
Assigns alternate tracks for defective tracks. Reads the control cards. Scans control cards. Writes track O. ._------, Performs program initialization and reads control cards. Formats the VTOC. Starts initializing virtual disks when volume label checking is net
desired.
Gets an alternate track for a defective track.
Checks whether volume label checking was requested when assigning
alternate tracks.
Checks to see if track is really defective befere assigning
alternate. This check is optional. Updates the VTOC after an alternate track assignment.
Tests tracks during initialization. Performs program initialization.
Issues message identifying defective track and the alternate
assigned.
Checks volume label when initializing virtual disks. Writes the IPt program on disk. Writes the VTOC. .J
Figure 1-2. Virtual Disk Initialization Program Label tirectory
Chapter 1. IBCDASDI--The Virtual Disk Initialization Program 11
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