REFERENCE MATERIAL
The following publications detail information on the 3800 printing
subsystem: Reference Manual fer the IBM 3800 Printing Subsystea GC20-1775 Concepts of the IBM 3800 Printing Subsystem GC20-3829 Introducing the
Programming IBM 3800 Printing Subsystem and Its GC20-3846 OS/YS2 IBM 3800 Printing Subsystem Programmer's Guide, OS/YS1, SRL AND PROGRAM LOGIC PUBLICATIONS The following publications contain information on VM/370 support of the 3800 printing subsystem: GC20-1800 Introduction GC20-1801 Planning and System Generation Guide GC20-1806 Operator's Guide GC20-1808 System Messages GC20-1807 System Programmer's Guide GC20-1820 CP Command Reference for General Users GC20-1821 Operating Systems in a Virtual Machine SY20-0882 Service Routines Program Logic Manual SY20-0884 Data Areas and Control Block Logic SY20-0886 System Logic and Prob1e. Determination Guide, Vol. 1 Section 1. Summary of Changes to the V8/370 System 1-9

3850 Mass Storage System (MSS) Extended Support Release 6 extends the initial dedicated support availatle for the 3850 Storage System (8SS). The 3850 8SS allcws system control of
very large data capacities (from 35 billion bytes to 472 tillion bytes). 8SS enhances operational efficiency by: • Eliminating the time to manually pick DASD packs or tape reels from a
data library • Reducing pack change/tape change time • Shortening the cycle time of a volume through a library system since
all volumes are mounted and demounted under the control of the system • Increasing data security by automatic volume mounting, storing and
retrieving via system control • Reducing space considerations for data libraries and ccmputer rooms • Reducing operational costs since the installation can place large
amounts of present tape and DASD shelf data under direct control cf
the system. Under Release 5, V8/370 provided dedicated 85S 3330V volumes. For
Release 6, MSS ainidisk support has been added. Under Release 6 an
installation may now: • Define virtual machine minidisks on 8SS 3330V volumes allowing the Y8/370 control program to dynamically mount and demount the volumes
as needed. The term 3330V refers to a DASD device address on which
an "SS volume aay be mounted and whose address is known to either the V8/370 control program or to a guest virtual machine. • Dedicate or attach an 8SS 3330V device address to a 3330-1 virtual
device such that the virtual machine needs no 8SS If the 3330V is specified as a 3330-1, the V8/370 control prograa intercepts
and processes all I/O operations to that device. The virtual machine
accesses the 3330V as if it were a 3330-1. The control program handles all error recovery procedures unique to 3330V's. • Specify that the V8/370 control program is to select any available 3330V device address and mount the required MS5 volume as part of the VM/370 dedicate or attach processing. • Dedicate or attach a 3330V device to a virtual machine as a virtual 3330V device. The virtual machine then handles all error recovery
procedures directly. • Utilize the modified cylinder fault processing availatle in the most
recent M5S machine implemented levels. With this processing, an 8S5 3330V device address is not in a busy state while data is being
staged from an MSS cartridge to DASD to resolve a cylinder fault
condition.
An MSS communicator program that runs in a virtual machine under OS/VS1 or MVS forms the interface between V8/370 and the mass storage
control (MSC). This program mounts the requested volume and returns
information to CP that the volume has been mounted. 1-10 IBM VM/370 Release 6 Guide