Page of GC20-1807-7 As Updated Aug 1, 1979 by TNL GN25-0492 On return to the issuer of DIAGNOSE '2C':
If code '01' is specified: Register Rx will contain the DASD
location (in VM/370 control program internal format) of the start of
the error recording area. Ry contains, in the low-order halfword,
the number of error recording cylinders. ir code 'VL' specified; Register Rx will contain the DASD location of the first error record (in CCPD format). The value
actually points to the last frame record written, or record 2 if no
frame records present.
If code '04' is specified: Register Ry will contain a X'02' in the
low-order byte if frame records are present on the error recording
cylinders; X'OO' if no frame records present. Codes '02' and '04' may both be specified (code '06') on invoking DIAGNOSE. Eoth an Rx and Ry value must be specified. DIAGNOSE Code X'30' -- Read One Page of lOGREC
Data
Execution of DIAGNOSE Code X'30' allows a user with privilege class C,
E, or F to read one page of the system error recording area. The
register specified as Rx contains the DASD location (in VM/370 control
program internal format) of the desired record. The Ry register
contains the virtual address of a page-size buffer to receive the data.
The DMKRPAGT routine supplies the page of data. The condition codes
returned are:
Condition o
1
2
3 Me.@il!.9 Successful read, data available
End of cylinder, no data 1/0 error
Invalid cylinder, outside recording area DIAGNOSE Code X'34' --Read System Dump Spool F i I e
A user with privilege class C or E can read the system spool file by
issuing a DIAGNOSE Code X'34' instruction. However, this Diagnose Code
cannot read spool files that contain VMDUMP records --use DIAGNOSE Code X'14' for this purpose. If a program attempts to use DIAGNOSE Code X'34' to read VMDUMP records, CP returns a condition code of 2. The
register specified as Rx contains the virtual address of a page-size
buffer to receive the data. The Ry register, which must not be register
15, contains the virtual address of the spool input card reader. Ry+1,
on return, may contain error codes as follows:
Condition
__ __
o
1
2
3
3
3
3
Ry+1 4
8
12
16 Data transfer successful
End of file
File not found
Device address invalid
Device type invalid
Device busy
Fatal paging 1/0 error 196 IBM VM/370 System ?Logrammer's Guide

Page of GC20-1807-7 As Updated April 1, 19S1 by TNL GN25-0S29 The DMKDRDMP routine searches the system chain of spool input files for the dump file belonging to th€ user issuing the DIAGNOSE instruction. The first (or next) record from the dump file is provided
to the virtual machine via and the condition code is set to
zero. The dump file is closed via VM/370 console function CLOSE. DIAGNOSE Code X'38' --Read System Symbol Table Execution of DIAGNOSE Code X'3S' causes the routine DMKDRDSY to read the
system table into storage. The register specified as Rx contains the
address of the page buffer to contain the symbol table. DIAGNOSE Code X'3C' --VM/370 Directory
Execution of DIAGNOSE Code X'3C' allows a user to dynamically update the V8/370 directory. The register specified as Rx contains the first 4 bytes of the volume identification. The first two bytes of Ry contain
the last 2 bytes of the volume identification. The routine DKKUDRDS dynamically updates the directory. I DIAGNOSE Code X'48' -- Issue SVC 76 From a Second , Level VM/370 Virtual Machine
A second level VM/370 operating system issues SVC 76 using this DIAGNOSE. SVC 76 handles IIC error recording for virtual operating
systems. For instance, a virtual machine issues SVC 76 to record data
about hardware errors that occur on devices dedicated to it. Rl is the Rx register. The By register is not used in this DIAGNOSE. R1 must contain either of two values: X'04' ind1cates an SVC 76 request from a VM/370 virtual machine X' OS' indicates that a virtual machine issued DIAGNOSE X' 48'
CP checks first for the X'04' value. If it is present, CP sets VMSPMFLG in the virtual machine's VMBLOK to X'04' and processes the SVC 76 request on behalf of the virtual machine.
If R1 contains a X'08' value, CP sets
machine's VMBLOK to X'OS'. It then reflects
virtual machine. The virtual machine then
recording. VMSPMFLG the SVC handles
in the virtual
76 back to the
its own error
For more information on SVC 76 and I/O error recording procedures,
refer to .!M/370 OLTSEP End Be£2!:.sing Guide, GC2Q-1S09. DIAGNOSE Code X'4C' --Generate Accounting
Records for the Virtual User
This code can be issued only ty a user with the account option (ACCT) in
his directory.
Rx contains the virtual address of either a 24-byte parameter list
identifying the "charge to" user, or a variable length data area that is
to be punched into the accounting card. The interpretation of the Part 2. Control Program (CP) 197