You use PPB-Update-Mask field to specify:
The update mask is a single byte value (PIC X). The individual bits of this byte are defined for PF-Flush-Panel, PF-Scroll-Panel, PF-Write-Panel and PF-Read-Panel as shown below:
| Bit | Meaning When Set |
|---|---|
| 7 | Unused. Reserved for future use and must be set to 0. |
| 6 | Unused. Reserved for future use and must be set to 0. |
| 5 | Any update to the attributes in a panel is to show on the screen immediately (provided the panel is enabled). If this bit is not set, the update does not show on the screen until the next call to PF-Flush-Panel is made. |
| 4 | Any update to the text in a panel is to show on the screen immediately (provided the panel is enabled). If this bit is not set, the update does not show on the screen till the next call to PF-Flush-Panel is made. |
| 3 | The attributes in the specified area of a panel are to be replaced by the attribute specified in PPB-Fill-Attribute in Panels-Parameter-Block. This bit is mutually exclusive with bit 1; setting bits 3 and 1 causes unpredictable results. |
| 2 | The text in the specified area of a panel is to be replaced by the character specified in the PPB-Fill-Character in Panels-Parameter-Block. This bit is mutually exclusive with bit 0; setting bits 2 and 0 causes unpredictable results. |
| 1 | The attributes in the specified area are to be replaced by the attributes provided in the attribute buffer. When used, this buffer must always be specified as the third parameter in the call to Panels. This bit is mutually exclusive with bit 3; setting bits 1 and 3 causes unpredictable results. |
| 0 | The text in the specified area is to be replaced by the text provided in the text buffer. When used, this buffer must always be specified as the second parameter in the call to Panels. This bit is mutually exclusive with bit 2. Setting bits 0 and 2 causes unpredictable results. |