gtpd1m1t | Database Reference |
The formatter examines an input card for errors and determines the desired size and number of records per track. It then converts the starting and ending disk addresses (CCCCCHH) to binary and builds the count fields for the track. The count fields are then written to the disk. All I/O to the disk is performed by EXCP and tested for errors. If this is not the last track specified in the ending address of the input card, the track number is incremented and the count fields are built and written again. When the ending address is reached, another card is read in and the previous procedure is repeated. When the END card is read, a listing that contains the location, size, and duplication factor of every track on the pack is sent to the printer. The listing also includes the address of the VTOC and the addresses of any tracks that were not formatted. If you want a status report without formatting the pack, use an END card with the device type specified so that you read, but do not write, to the disk. An end-of-job message is then sent.
If the same type of record will be defined in 2 or more noncontiguous areas on disk, you will need 2 or more cards to describe these areas.
Size and duplication indicators on the input card are used to set the last 3 bits of the disk record numbers to the correct value for small and large record types (2KB and 4KB records are compatible with MVS record numbers). (See the information about macro usage conventions in TPF General Macros for details about the meaning of these bits.)
A 3390 installed in 3380 emulation mode appears to the TPF system as a 3380 and must be coded as if it was a physical 3380. Therefore, the duplication factor is required for emulated 3380s.
Table 13 shows the number of records per track and the number of
cylinders for TPF-supported DASD.
Table 13. Record Allocation on TPF-Supported DASD
Device | Large Rec/Trk | Small Rec/Trk | 2KB Rec/Trk | 4KB Rec/Trk | Number of Cylinders |
---|---|---|---|---|---|
3350 | 15 | 34 | 8 | 4 | 555 |
3375 | 25 | 46 | 14 | 8 | 959 |
3380 | 30 | 53 | 18 | 10 | 2655 |
3390 | 33 | 55 | -- | 12 | 3339 |
9345 | 27 | 47 | -- | 10 | 2156 |
2KB (IPC) records are not supported on 3390 and newer devices. The TPF system does not use 2KB records or support SIPC data sets on general files.