The record format field in the data control block indicates that the machine code control character has been placed in each logical record. If the record is written, the appropriate byte must contain the command code bit configuration specifying both the write and the desired carriage or stacker select operation.
The machine code control characters for a printer are:
| Print—Then Act | Action | Act Immediately without Printing |
|---|---|---|
| X'01' | Print only (no space, overprint) | |
| X'09' | Space 1 line | X'0B' |
| X'11' | Space 2 lines | X'13' |
| X'19' | Space 3 lines | X'1B' |
| X'5A' | The rest of the record is page mode data. This requires the use of the Print Services Facility™ (PSF) and a page mode printer such as an IBM® 3800, IBM 3900, IBM 3820, or IBM 3827. The data may be sysout. | |
| X'89' | Skip to channel 1 | X'8B' |
| X'91' | Skip to channel 2 | X'93' |
| X'99' | Skip to channel 3 | X'9B' |
| X'A1' | Skip to channel 4 | X'A3' |
| X'A9' | Skip to channel 5 | X'AB' |
| X'B1' | Skip to channel 6 | X'B3' |
| X'B9' | Skip to channel 7 | X'BB' |
| X'C1' | Skip to channel 8 | X'C3' |
| X'C9' | Skip to channel 9 | X'CB' |
| X'D1' | Skip to channel 10 | X'D3' |
| X'D9' | Skip to channel 11 | X'DB' |
| X'E1' | Skip to channel 12 | X'E3' |
The machine code control characters for a card punch device are as follows:
| Control Code | Action |
|---|---|
| X'01' | Select stacker 1 |
| X'41' | Select stacker 2 |
| X'81' | Select stacker 3 |
Other command codes for specific devices are contained in IBM System Reference Library publications describing the control units or devices.