RISCOS.com

www.riscos.com Technical Support:
Programmer's Reference Manual

 

Table B: Modes


The modes available in RISC OS depend on the configured monitor type (see *Configure MonitorType on *Configure MonitorType) and the model of computer. Below is a table of all modes provided by RISC OS, which shows:

  • the mode number
  • the text resolution in columns × rows
  • the graphics resolution in pixels, which corresponds to the clarity of the mode's display
  • the resolution in OS units, which corresponds to the area of workspace shown by the mode
  • the number of logical colours available
  • the memory used to display the screen (to the nearest 0.1Kbyte)
  • the vertical refresh rate to the nearest Hz (invalid for monitor type 5), which indicates the degree of flickering that you may perceive
  • the bandwidth used to display the screen (to the nearest 0.1Mbyte/second), which corresponds to the load the mode places on the computer
  • the monitor types that support that mode:
    Type Monitor
    0 50Hz TV standard colour or monochrome monitor
    1 Multi-frequency monitor
    2 64Hz high-resolution monochrome monitor
    3 60Hz VGA-type monitor
    4 Super-VGA-type monitor (not available in RISC OS 2)
    5 LCD (liquid crystal display) (not available in RISC OS 2)
  • the notes on the following page that are relevant to the mode.
Mode Text resolution Pixel resolution OS units resolution Logical colours Memory used Refresh rate Bandwidth Monitor types Notes
0 80 × 32 640 × 256 1280 × 1024 2 20K 50Hz 1M/s 0,1,3,4,5 (3)
1 40 × 32 320 × 256 1280 × 1024 4 20K 50Hz 1M/s 0,1,3,4,5 (3)
2 20 × 32 160 × 256 1280 × 1024 16 40K 50Hz 2M/s 0,1,3,4,5 (3) (5) (7)
3 80 × 25 Text only Text only 2 40K 50Hz 2M/s 0,1,3,4,5 (3) (5)
4 40 × 32 320 × 256 1280 × 1024 2 20K 50Hz 1M/s 0,1,3,4,5 (3)
5 20 × 32 160 × 256 1280 × 1024 4 20K 50Hz 1M/s 0,1,3,4,5 (3)
6 40 × 25 Text only Text only 2 20K 50Hz 1M/s 0,1,3,4,5 (3) (5) (7)
7 40 × 25 Teletext Teletext 16 80K 50Hz 4M/s 0,1,3,4,5 (3) (5)
8 80 × 32 640 × 256 1280 × 1024 4 40K 50Hz 2M/s 0,1,3,4,5 (3)
9 40 × 32 320 × 256 1280 × 1024 16 40K 50Hz 2M/s 0,1,3,4,5 (3)
10 20 × 32 160 × 256 1280 × 1024 256 80K 50Hz 4M/s 0,1,3,4,5 (3)
11 80 × 25 640 × 250 1280 × 1000 4 40K 50Hz 2M/s 0,1,3,4,5 (3) (8)
12 80 × 32 640 × 256 1280 × 1024 16 80K 50Hz 4M/s 0,1,3,4,5 (3)
13 40 × 32 320 × 256 1280 × 1024 256 80K 50Hz 4M/s 0,1,3,4,5 (3)
14 80 × 25 640 × 250 1280 × 1000 16 80K 50Hz 3.9M/s 0,1,3,4,5 (3) (8)
15 80 × 32 640 × 256 1280 × 1024 256 160K 50Hz 8M/s 0,1,3,4,5 (3)
16 132 × 32 1056 × 256 2112 × 1024 16 132K 50Hz 6.6M/s 0,1 (6)
17 132 × 25 1056 × 250 2112 × 1000 16 132K 50Hz 6.5M/s 0,1 (6) (8)
18 80 × 64 640 × 512 1280 × 1024 2 40K 50Hz 2M/s 1
19 80 × 64 640 × 512 1280 × 1024 4 80K 50Hz 4M/s 1
20 80 × 64 640 × 512 1280 × 1024 16 160K 50Hz 8M/s 1
21 80 × 64 640 × 512 1280 × 1024 256 320K 50Hz 16M/s 1
22 96 × 36 768 × 288 768 × 576 16 108K 50Hz 5.4M/s 0,1 (1) (9)
23 144 × 56 1152 × 896 2304 × 1792 2 126K 64Hz 8.1M/s 2
24 132 × 32 1056 × 256 2112 × 1024 256 264K 50Hz 13.2M/s 0,1 (6)
25 80 × 60 640 × 480 1280 × 960 2 37.5K 60Hz 2.3M/s 1,3,4,5
26 80 × 60 640 × 480 1280 × 960 4 75K 60Hz 4.5M/s 1,3,4,5
27 80 × 60 640 × 480 1280 × 960 16 150K 60Hz 9M/s 1,3,4,5
28 80 × 60 640 × 480 1280 × 960 256 300K 60Hz 18M/s 1,3,4,5
29 100 × 75 800 × 600 1600 × 1200 2 58.6K 56Hz 3.3M/s 1,4 (1) (2)
30 100 × 75 800 × 600 1600 × 1200 4 117.2K 56Hz 6.6M/s 1,4 (1) (2)
31 100 × 75 800 × 600 1600 × 1200 16 234.4K 56Hz 13.2M/s 1,4 (1) (2)
33 96 × 36 768 × 288 1536 × 1152 2 27K 50Hz 1.4M/s 0,1 (1)
34 96 × 36 768 × 288 1536 × 1152 4 54K 50Hz 2.7M/s 0,1 (1)
35 96 × 36 768 × 288 1536 × 1152 16 108K 50Hz 5.4M/s 0,1 (1)
36 96 × 36 768 × 288 1536 × 1152 256 216K 50Hz 10.8M/s 0,1 (1)
37 112 × 44 896 × 352 1792 × 1408 2 38.5K 60Hz 2.3M/s 1 (1)
38 112 × 44 896 × 352 1792 × 1408 4 77K 60Hz 4.6M/s 1 (1)
39 112 × 44 896 × 352 1792 × 1408 16 154K 60Hz 9.2M/s 1 (1)
40 112 × 44 896 × 352 1792 × 1408 256 308K 60Hz 18.5M/s 1 (1) (3) (4)
41 80 × 44 640 × 352 1280 × 1408 2 27.5K 60Hz 1.7M/s 1,3,4,5 (1) (3) (4)
42 80 × 44 640 × 352 1280 × 1408 4 55K 60Hz 3.3M/s 1,3,4,5 (1) (3) (4)
43 80 × 44 640 × 352 1280 × 1408 16 110K 60Hz 6.6M/s 1,3,4,5 (1) (3)
44 80 × 25 640 × 200 1280 × 800 2 15.7K 60Hz 0.9M/s 1,3,4,5 (1) (3)
45 80 × 25 640 × 200 1280 × 800 4 31.3K 60Hz 1.9M/s 1,3,4,5 (1) (3)
46 80 × 25 640 × 200 1280 × 800 16 62.5K 60Hz 3.8M/s 1,3,4,5 (1) (3)
Notes on display modes
  1. These modes are not available in RISC OS 2.00, nor (except for mode 31) are they available in RISC OS 2.01.
  2. These modes are not available on early models of RISC OS computers (ie the Archimedes 300, 400 and 400/1 series, and the A3000), because they are unable to clock VIDC at the necessary rate.
  3. These modes are handled differently with a VGA or Super-VGA-type monitor. If you are using such a monitor:
    • RISC OS 2.00 does not implement these modes.
    • These modes are all displayed on a screen having 352 raster lines. Where a mode has fewer than 352 vertical pixels, it is centred on the screen with blank rasters at the top and bottom. Because of their appearance these modes are known as letterbox modes.
    • The refresh rate is 70Hz.
    • The bandwidths shown in the table for these modes are lower than these monitor types consume, because no allowance has been made for the blank rasters.
    • Early models of RISC OS computers (ie the Archimedes 300, 400 and 400/1 series, and the A3000) scan these modes some 4.7% slow. Again this is because they are unable to clock VIDC at the necessary rate. Most VGA and Super-VGA-type monitors can still successfully lock onto this signal, but some may not. Furthermore, these models do not provide a Sync Polarity signal. This makes the effect of letterbox modes (see above) more severe.
  4. Early models of RISC OS computers (ie the Archimedes 300, 400 and 400/1 series, and the A3000) also scan these modes some 4.7% slow with multi-frequency monitors. Again this is because they are unable to clock VIDC at the necessary rate.
  5. These modes do not display graphics, and are provided for compatibility with BBC/Master series computers.
  6. In these modes circles, arcs, sectors and segments do not look circular. This is because the aspect ratio of the pixels is not in a 1:2, 1:1 or 2:1 ratio.
  7. These are gap modes, where the colour of the gaps is not necessarily the same as the text background.
  8. These modes are not a multiple of eight pixels high. By default, in these modes the bottom of the screen corresponds to the bottom line of ECF patterns, but the top line will not correspond to the top line of ECF patterns.
  9. This mode is not available in RISC OS 3 (version 3.00). It provides a double-sized display suitable for use by visually impaired people. Unfortunately some applications may not provide correct displays when used with this mode.
Other notes

Mode 32 has not been defined.

If an attempt is made to select a mode which is not appropriate to the current monitor type (or OS version), a suitable mode for that monitor is used. For example, an attempt to select mode 23 on a type 0 monitor will result in mode 0 being used.

In 256 colour modes, there are some restrictions on the control of the colours. Only 64 base colours may be selected; 4 levels of tinting turn the base colours into 256 shades. Also, the selection from the colour palette of 4096 shades is only possible in groups of 16.

This edition Copyright © 3QD Developments Ltd 2015
Last Edit: Tue,03 Nov 2015