Difference between revisions of "OSBYTE &FE"
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[[Category:OSBYTE]] | [[Category:OSBYTE]] | ||
| − | OSBYTE &FE (254) - Read/Write available RAM | + | ==OSBYTE &FE (254) - Read/Write available RAM, keyboard extensions== |
| + | (BBC MOS 1.xx) | ||
These bits refer to 16K/32K machine: | These bits refer to 16K/32K machine: | ||
When read &40=16K | When read &40=16K | ||
| Line 7: | Line 8: | ||
(Electron OS) | (Electron OS) | ||
This value returns 0 and is otherwise undefined | This value returns 0 and is otherwise undefined | ||
| − | (Acorn MOS 2. | + | (Acorn MOS 2.xx) |
This value returns 1 and is otherwise undefined | This value returns 1 and is otherwise undefined | ||
| − | (Acorn MOS 3. | + | (Acorn MOS 3.xx) |
Read/Write effect of shift on Numeric pad | Read/Write effect of shift on Numeric pad | ||
A zero in this location makes SHIFT-keypad presses act like their main | A zero in this location makes SHIFT-keypad presses act like their main | ||
| − | keyboard counterparts.A | + | keyboard counterparts. A nonzero value means shift is ignored. |
| − | (RISC OS | + | (RISC OS) |
A zero in this location enables both SHIFT and CTRL-keypad presses: | A zero in this location enables both SHIFT and CTRL-keypad presses: | ||
| − | For keys 128 and above (ie.the base has been altered with OSByte 238) | + | For keys 128 and above (ie. the base has been altered with OSByte 238) |
CTRL-keypad gives keypad key EOR&20 | CTRL-keypad gives keypad key EOR&20 | ||
SHIFT-keypad gives keypad key EOR&10 | SHIFT-keypad gives keypad key EOR&10 | ||
For keys below 128 | For keys below 128 | ||
CTRL and SHIFT are ignored | CTRL and SHIFT are ignored | ||
| + | (Other) | ||
| + | On non-Acorn systems with full keyboards, if bit 7 is set, bit 6 indicates | ||
| + | whether function keys return native regular character codes, or return | ||
| + | RISC OS semi-regular key codes. | ||
| + | b7=1, b6=0 - return whatever the host system's native keycodes | ||
| + | b7=1, b6=1 - return semi-regular key codes, f0-f9=&80-&89, f10-f12=&CA-&CC. | ||
| + | |||
| + | *FX254,128 can be used to portably select native keycodes. Where *FX254 is not | ||
| + | supported, native keycodes will be used anyway. Where *FX254 is supported, it | ||
| + | will select native keycodes, which should be the default on startup. | ||
| + | *FX254,192 can be used to portably select RISCOS-style semi-regular keycodes. | ||
| + | Where *FX254,192 is not supported, this will normally be RISC OS, which will | ||
| + | be using semi-regular keycodes anyway. Where *FX254,192 is supported, it will | ||
| + | select RISCOS-style semi-regular keycodes. | ||
| + | |||
| + | The only incompatability is if this is used on a 16K BBC model A. | ||
==See Also== | ==See Also== | ||
| − | * http://mdfs.net/Docs/Comp/ | + | * http://mdfs.net/Docs/Comp/KeyMap/RISCOS |
| + | * http://mdfs.net/Docs/Comp/KeyMap/Regular | ||
| + | * http://mdfs.net/Docs/Comp/KeyMap/BBFW | ||
[[User:Jgharston|Jgharston]] 23:21, 26 May 2009 (UTC) | [[User:Jgharston|Jgharston]] 23:21, 26 May 2009 (UTC) | ||
| + | [[User:Jgharston|Jgharston]] ([[User talk:Jgharston|talk]]) 04:57, 20 July 2020 (CEST) | ||
Latest revision as of 03:57, 20 July 2020
OSBYTE &FE (254) - Read/Write available RAM, keyboard extensions
(BBC MOS 1.xx)
These bits refer to 16K/32K machine:
When read &40=16K
&80=32K
(Electron OS)
This value returns 0 and is otherwise undefined
(Acorn MOS 2.xx)
This value returns 1 and is otherwise undefined
(Acorn MOS 3.xx)
Read/Write effect of shift on Numeric pad
A zero in this location makes SHIFT-keypad presses act like their main
keyboard counterparts. A nonzero value means shift is ignored.
(RISC OS)
A zero in this location enables both SHIFT and CTRL-keypad presses:
For keys 128 and above (ie. the base has been altered with OSByte 238)
CTRL-keypad gives keypad key EOR&20
SHIFT-keypad gives keypad key EOR&10
For keys below 128
CTRL and SHIFT are ignored
(Other)
On non-Acorn systems with full keyboards, if bit 7 is set, bit 6 indicates
whether function keys return native regular character codes, or return
RISC OS semi-regular key codes.
b7=1, b6=0 - return whatever the host system's native keycodes
b7=1, b6=1 - return semi-regular key codes, f0-f9=&80-&89, f10-f12=&CA-&CC.
*FX254,128 can be used to portably select native keycodes. Where *FX254 is not
supported, native keycodes will be used anyway. Where *FX254 is supported, it
will select native keycodes, which should be the default on startup.
*FX254,192 can be used to portably select RISCOS-style semi-regular keycodes.
Where *FX254,192 is not supported, this will normally be RISC OS, which will
be using semi-regular keycodes anyway. Where *FX254,192 is supported, it will
select RISCOS-style semi-regular keycodes.
The only incompatability is if this is used on a 16K BBC model A.
See Also
- http://mdfs.net/Docs/Comp/KeyMap/RISCOS
- http://mdfs.net/Docs/Comp/KeyMap/Regular
- http://mdfs.net/Docs/Comp/KeyMap/BBFW
Jgharston 23:21, 26 May 2009 (UTC) Jgharston (talk) 04:57, 20 July 2020 (CEST)
