IBM System/370 145 Manual page 189

• Specify a CCW when the sum of the data address and count points to a
storage location outside the DOS system area (DOS supervisor and
partition area)
While a pseudo interval timer is maintained at simulated DOS decimal
location 80, accurate time of day is not guaranteed, because the timer
is running only when the OS DOS emulator partition/region is executing,
and a time lag occurs during the interval required to update the timer.
The following I/O devices and telecommunications terminals are
supported by the OS DOS emulator:
• 1052 Printer-Keyboard (emulated on a 3210-1 or 3215)
• 1285, 1281, 1288 Optical Readers (the latter two not in document
mode if response times are required for pocket selection)
• 1403, 1443, 3211 Printers
• 1404 Printer for continuous form operations only (emulated on a 1403
or 3211 Printer)
• 1442, 2520, 2540 Card Read Punches
• 2501 Card Reader
• 2311 Disk Storage Drive
• 2314 and 2319 Direct Access Storage Facilities
• 2321 Data Cell Drive
• 2400- and 3400-series magnetic tape units
• 2611 Paper Tape Reader
• 3505 Card Reader
• 3525 Card Punch
• 3330-series disk storage
• All the start/stop and binary synchronous terminals supported by
BTAM except the 2260 Display Station (local) and 1710/1772 Audio
Response Units
EMULATOR JOB SUBMISSION AND GENERAL OPERATION
DOS emulation is initiated as a single-step OS job via the input
stream.
An OS DOS emulator job can consist of one or more DOS jobs.
The OS OOS emulator program, which must reside in SYS1.LINKLIB or a user
job library, is specified in the .EXEC job control statement included in
the job control, for the OS DOS emulator job. The following also must be
identified in the job control sta·tements for the OS OOS emulator job:
1. The DOS system residence device and operator console device
2. The location of the DOS IP:L input stream
3. I/O assignments for the staging of DOS unit record I/O operations
4. All the I/O devices except the operator console device that will
be used by the DOS supervi:sor and DOS programs that are emulated
as part of this DOS emulator job
The DOS input streams for OOS partitions can be located in the OS
input stream or on separate data :sets.
When the DOS emulation job is initiated, the DOS emulator program is
loaded into the OS DOS emulator p,artition/region. The DOS emulator
program performs control block and table initialization and initiates an
IPL from the DOS system residence volume. Once the DOS supervisor has
been loaded and has established the OOS partitions, DOS job execution
begins. DOS programs are loaded into the defined DOS partitions and
emulated. Messages to the operator from the DOS emulator program are
issued in standard OS format· and include a unique identification to
indicate that they are OS DOS emu.lator messages. If the MCS option is
A Guide to the IBM System/370
Mod~el
145 179