MODE 9
MODE 9 - 40x32x16
MODE 9 is a medium-resolution screen MODE, selectable with the *MODE command or the NewModes sideways ROM module, that replicates the functionality of the native RISC OS MODE 9.[1]
The MODE 9 code adapts the MODE 2 screen to provide a 16-colour version
of MODE 1, 40 × 32 characters in 16 colours. It does this by redefining
the character set to provide thin characters.
Type | Bitmapped | |
Resolution | Text | 40 × 32 characters |
Graphics | 160 × 256 | |
Character size | 4 × 8 pixels | |
Pixel aspect | 2:1 (wide) | |
Bits per pixel | 2 | |
Default palette | Logical colour | Actual colour |
---|---|---|
0 | 0 (black) | |
1 | 1 (red) | |
2 | 2 (green) | |
3 | 3 (yellow) | |
4 | 4 (blue) | |
5 | 5 (magenta) | |
6 | 6 (cyan) | |
7 | 7 (white) | |
8 | 8 (flashing black/white) | |
9 | 9 (flashing red/cyan) | |
10 | 10 (flashing green/magenta) | |
11 | 11 (flashing yellow/blue) | |
12 | 12 (flashing blue/yellow) | |
13 | 13 (flashing magenta/green) | |
14 | 14 (flashing cyan/red) | |
15 | 15 (flashing white/black) | |
Memory | allocated | 20480 bytes |
on screen | 20480 bytes | |
Address range | Model B etc. | &3000..&7FFF |
Configuration | Video ULA control register | &D4 |
Video ULA palette register file | &07 &17 &26 &36 &47 &57 &66 &76 &84 &94 &A0 &B0 &C4 &D4 &E0 &F0 | |
CRTC register file | &3F &28 &31 &24 &26 &00 &20 &22 &01 &07 &67 &08 |
MODE 9 can be created manually with the following code running in the I/O processor.
BASIC: MODE 2 :REM Base MODE ?&30A=39 :REM Characters per line ?&34F=8 :REM Bytes per character *FX154,212 6502: LDA #22:JSR OSWRCH LDA #02:JSR OSWRCH \ Base MODE LDA #&27:STA &30A \ Characters per line LDA #&08:STA &34F \ Byte per character LDA #154:LDX #212:JSR OSBYTE \ Cursor width
The character set needs to be redefined to be four pixels wide, such as with the one used with NewModes.
MODE 9 - 10x25x16
MODE 9 is also the unofficial title of an ultra-low resolution screen MODE, developed by Ian Robertson and published in The Micro User magazine (November 1985, p.123). It works on the BBC Micro but not the Electron, or the Archimedes where MODE 9 is the official 16-colour version of MODE 1).
The MODE 9 code adapts the MODE 6 screen to provide a 10 × 25 text
display in 16 colours. The MOS does not allow complete support of this MODE
and some bugs can be seen: for instance, text windows do not work
correctly.
Type | Bitmapped, text only ('ASCII') | |
Resolution | Text | 10 × 25 characters |
Graphics | n/a | |
Character size | 8 × 10 pixels, top 8 lines user definable | |
Pixel aspect | 4:1 (wide) | |
Bits per pixel | 4 | |
Default palette | Logical colour | Actual colour |
---|---|---|
0 | 0 (black) | |
1 | 1 (red) | |
2 | 2 (green) | |
3 | 3 (yellow) | |
4 | 4 (blue) | |
5 | 5 (magenta) | |
6 | 6 (cyan) | |
7 | 7 (white) | |
8 | 8 (flashing black/white) | |
9 | 9 (flashing red/cyan) | |
10 | 10 (flashing green/magenta) | |
11 | 11 (flashing yellow/blue) | |
12 | 12 (flashing blue/yellow) | |
13 | 13 (flashing magenta/green) | |
14 | 14 (flashing cyan/red) | |
15 | 15 (flashing white/black) | |
Memory | allocated | 8192 bytes |
on screen | 8000 bytes | |
Address range | Model B etc. | &6000..&7FFF |
Configuration | Video ULA control register | &80 |
Video ULA palette register file | &07 &16 &25 &34 &43 &52 &61 &70 &8F &9E &AD &BC &CB &DA &E9 &F8 | |
CRTC register file | &3F &28 &31 &24 &1E &02 &19 &1B &01 &09 &67 &09 (from table in MOS 1.20 at &C492..&C49D) |
MODE 9 can be created manually with the following code running in the I/O processor.
BASIC: MODE 6 :REM Base MODE ?&30A=9 :REM Characters per line ?&34F=32 :REM Bytes per character ?&360=15 :REM Number of colours ?&361=1 :REM Pixels per byte ?&362=&AA :REM Pixel left mask ?&363=&55 :REM Pixel right mask VDU 20 :REM Reset palette *FX154,128 6502: LDA #22:JSR OSWRCH LDA #06:JSR OSWRCH \ Base MODE LDA #&09:STA &30A \ Characters per line LDA #&20:STA &34F \ Byte per character LDA #&0F:STA &360 \ Number of colours LDA #&01:STA &361 \ Pixels per byte LDA #&AA:STA &362 \ Pixel left mask LDA #&55:STA &363 \ Pixel right mask LDA #20:JSR OSWRCH \ Reset palette LDA #154:LDX #128:JSR OSBYTE \ Cursor width
See Also
References
Screen display MODEs |
---|
MODE 0 | MODE 1 | MODE 2 | MODE 3 | MODE 4 | MODE 5 | MODE 6 | MODE 7 |
Jgharston (talk) 17:22, 12 October 2016 (UTC) beardo 12:52, 20 September 2006 (BST)