Difference between revisions of "OSBYTE &75"
m (moved OSBYTE 75 to OSBYTE &75) |
m (Bit 4 is also used on the BBC B+.) |
||
| (5 intermediate revisions by 2 users not shown) | |||
| Line 2: | Line 2: | ||
OSBYTE &75 (117) - Read VDU Status Byte | OSBYTE &75 (117) - Read VDU Status Byte | ||
| + | On exit: | ||
X=b0 Print output enabled by VDU2 | X=b0 Print output enabled by VDU2 | ||
| − | b1 | + | b1 Scrolling disabled |
b2 Paged scrolling selected by VDU14 | b2 Paged scrolling selected by VDU14 | ||
| − | b3 Text window in force ie | + | b3 Text window in force, ie software scrolling |
| − | b4 In a shadow mode | + | b4 In a shadow mode on Master |
b5 In VDU5 mode | b5 In VDU5 mode | ||
b6 Cursor editing in progress | b6 Cursor editing in progress | ||
b7 Screen disabled with VDU21 | b7 Screen disabled with VDU21 | ||
| − | |||
| − | |||
| − | ==See | + | Note, bit 4 is only set by shadow screen modes on the Master series and the |
| + | BBC B+. With shadow screen systems on the BBC B and Electron a different flag | ||
| + | is used. | ||
| + | |||
| + | ==See also== | ||
| + | * [[OSWRCH]] | ||
| + | * [[OSBYTE &49]] - Check for Integra-B shadow memory | ||
| + | * [[OSBYTE &6C]] - Select Master/Integra-B shadow memory | ||
| + | * [[OSBYTE &6F]] - Select BBC B shadow memory | ||
| + | * [[OSBYTE &70]] - Select memory for Master VDU access | ||
| + | * [[OSBYTE &71]] - Select memory for Master video display | ||
| + | * [[OSBYTE &72]] - Select future use of shadow memory | ||
| + | * [[OSBYTE &73]] - Select shadow bank | ||
| + | * [[OSBYTE &74]] - Check for Solidisk shadow memory | ||
| + | * [[Paging in video memory]] | ||
* http://mdfs.net/Docs/Comp/BBC/Osbyte00 | * http://mdfs.net/Docs/Comp/BBC/Osbyte00 | ||
[[User:Jgharston|Jgharston]] 21:53, 26 May 2009 (UTC) | [[User:Jgharston|Jgharston]] 21:53, 26 May 2009 (UTC) | ||
| + | [[User:Jgharston|Jgharston]] ([[User talk:Jgharston|talk]]) 20:33, 3 April 2015 (UTC) | ||
Latest revision as of 08:46, 28 December 2016
OSBYTE &75 (117) - Read VDU Status Byte
On exit:
X=b0 Print output enabled by VDU2
b1 Scrolling disabled
b2 Paged scrolling selected by VDU14
b3 Text window in force, ie software scrolling
b4 In a shadow mode on Master
b5 In VDU5 mode
b6 Cursor editing in progress
b7 Screen disabled with VDU21
Note, bit 4 is only set by shadow screen modes on the Master series and the BBC B+. With shadow screen systems on the BBC B and Electron a different flag is used.
See also
- OSWRCH
- OSBYTE &49 - Check for Integra-B shadow memory
- OSBYTE &6C - Select Master/Integra-B shadow memory
- OSBYTE &6F - Select BBC B shadow memory
- OSBYTE &70 - Select memory for Master VDU access
- OSBYTE &71 - Select memory for Master video display
- OSBYTE &72 - Select future use of shadow memory
- OSBYTE &73 - Select shadow bank
- OSBYTE &74 - Check for Solidisk shadow memory
- Paging in video memory
- http://mdfs.net/Docs/Comp/BBC/Osbyte00
Jgharston 21:53, 26 May 2009 (UTC) Jgharston (talk) 20:33, 3 April 2015 (UTC)
