Difference between revisions of "OSBYTE &73"
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OSBYTE &73 (115) - Select shadow RAM bank used | OSBYTE &73 (115) - Select shadow RAM bank used | ||
| + | On entry: | ||
X=0 Shadow bank 8 | X=0 Shadow bank 8 | ||
X=1 Shadow bank 9 | X=1 Shadow bank 9 | ||
| − | + | ||
| + | Electron OS: | ||
Blank/restore palette | Blank/restore palette | ||
| − | X=0 restores the palette | + | On entry: |
| − | + | X=0 restores the palette, on exit X=0 | |
| − | Software using NMIs in high | + | X<>0 sets the whole palette to black if in high resolution mode |
| − | + | on exit, X<4 | |
| + | |||
| + | Software using NMIs in high resolution screen modes can prevent snow | ||
| + | appearing on the screen during NMIs (due to ULA reuse) by blanking the | ||
| + | palette. | ||
| − | ==See | + | ==See also== |
| + | * [[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]] 21:52, 26 May 2009 (UTC) | [[User:Jgharston|Jgharston]] 21:52, 26 May 2009 (UTC) | ||
| + | [[User:Jgharston|Jgharston]] ([[User talk:Jgharston|talk]]) 20:32, 3 April 2015 (UTC) | ||
Latest revision as of 21:32, 3 April 2015
OSBYTE &73 (115) - Select shadow RAM bank used
On entry:
X=0 Shadow bank 8
X=1 Shadow bank 9
Electron OS:
Blank/restore palette
On entry:
X=0 restores the palette, on exit X=0
X<>0 sets the whole palette to black if in high resolution mode
on exit, X<4
Software using NMIs in high resolution screen modes can prevent snow appearing on the screen during NMIs (due to ULA reuse) by blanking the palette.
See also
- 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 21:52, 26 May 2009 (UTC) Jgharston (talk) 20:32, 3 April 2015 (UTC)
