Presentation space size
This field (bytes 19–23) contains the default and alternate presentation space sizes and a presentation space size code field. These fields are shown in Figure 1.
Bytes 19 and 21 contain the number of rows in the default presentation space and the alternate presentation space respectively. Bytes 20 and 22 contain the number of columns in the default presentation space and the alternate presentation space respectively.
Byte 23 identifies the presentation space size or indicates to use either the default or alternate presentation space size. The sizes that can be specified are:
- Bit setting 0123 4567
- (Byte 23) Meaning
- 0000 0000
- A presentation space is not defined.
- 0000 0001
- A presentation space of 12 by 40 bytes is used.
- 0000 0010
- A presentation space of 24 by 80 bytes is used.
- 0111 1110
- A presentation space as described by the default field is used.
- 0000 0011
- The default presentation space is 24 by 80 bytes, and the alternate presentation space is specified in the Query Reply (implicit partition size) structured field. If there is no implicit partition size specified, use usable area.
- 0111 1111
- Either the default or the alternate presentation space size is used.
- Bit setting 0123 4567
- (Byte 24) Meaning
- xxxx xx..
- Reserved
- .... ..00
- No compression
- .... ..01
- Compression bid
- .... ..10
- Reserved
- .... ..11
- Compression required