From: spence@cbmvax.commodore.com (Spencer Shanson)
Newsgroups: comp.sys.amiga.graphics
Subject: Re: Scan rates required.
Date: 24 Dec 92 17:55:49 GMT
Organization: Commodore, West Chester, PA

In article <1gb7o4INN6pq@newsman.csu.murdoch.edu.au> banks@csuvax1.csu.murdoch.edu.au (Corey Banks) writes:
>This is probably a FAQ (or should be) but could someone send me the scan rates
>for all the different modes (both horizontal and vertical) on the Amiga.  I
>mainly want the AGA stuff,  but I think I'll need all possible modes.  If you
>don't know all of them how about sending me the ones you know and I'll 
>summerize them.

AGA Modes
=========

The AGA Chip Set is capable of displaying all the modes that ECS could, and more
besides. The difference between AGA and ECS in terms of computer display is, of
course, the number of colours that can be displayed.

Here is a quick run-down of all the resolutions that can be displayed on a AA
system:

NTSC
----
Horizontal - 320, 640 or 1280 nominal
             362, 724 or 1448 overscanned

Vertical   - 200 non-interlaced, 400 interlaced
             241 non-interlaced overscanned, 481 interlaced overscanned

60Hz vertical refresh, 15.7kHz horizontal refresh


PAL
---

Horizontal - 320, 640 or 1280 nominal
             362, 724 or 1448 overscanned

Vertical   - 256 non-interlaced, 512 interlaced
             283 non-interlaced overscanned, 566 interlaced overscanned

50Hz vertical refresh, 15.6kHz horizontal refresh




VGA
---

Horizontal - 640 (also 320 and 160, but not very useful)

Vertical   - 480 non-interlaced, 960 interlaced
             495 non-interlaced overscanned, 990 interlaced overscanned

60Hz vertical refresh, 31.44kHz horizontal refresh


Euro72
------

This is a VGA-style display mode designed specifically for the European
market. In Europe, electricity runs at 50Hz (in the States, at 60Hz), and a 60Hz
refresh rate on the monitors 'beats' with the background lights. A 72Hz refresh
provides a nicer environment.

Horizontal - 640 (also 320 and 160, but not very useful)

Vertical   - 400 non-interlaced
             800 Interlaced

(No overscan is available)

~72Hz vertical refresh, 31.43kHz Horizontal refresh


Euro36
------

This is provided to give the European market a display of NTSC proportions, but
at the 72Hz refresh rate.

Horizontal - 320, 640 or 1280 nominal
             362, 724 or 1448 overscanned

Vertical   - 200 non-interlaced, 400 interlaced
             (no vertical overscan available)

~72Hz vertical refresh, 15.7kHz horizontal refresh


Super72
-------

Again, this is a 72Hz mode, but designed to give Enhanced-VGA style resolution
of 800x600. Although the 800x600 is interlaced, the high refresh rate reduces
the interlace flicker, and is a very useable mode (many of us use it as our
main display mode).

Horizontal - 800, 400 (or 200, but not very useful) nominal
             896, 448 overscanned

Vertical   - 300 non-interlaced, 600 interlaced
             314 non-interlaced overscanned, 628 interlaced overscanned

72Hz vertical refresh, 24.6kHz horizontal refresh




DblNTSC
-------

This mode is designed to provide similar resolution to normal NTSC, but at a
higher refresh rate. This is designed to be as much as possible a flicker-fixed
variant of the NTSC display.

Horizontal - 320, 640 (and 160, but not very useful) nominal
             338, 676 overscanned

Vertical   - 200 scan-doubled, 400, 800 interlaced nominal
             233 scan-doubled, 467, 934 interlaced overscanned

(Scan-doubling involves displaying each vertical line twice. This means that the
200 line display takes as much physical monitor space as the 400 line high
display, and therefore maintains aspect ratio).

~60Hz vertical refresh, 29.2kHz horizontal refresh


DblPAL
-----

This is to Pal what DblNTSC is to NTSC

Horizontal - 320, 640 (and 160, but not very useful) nominal
             338, 676 overscanned

Vertical   - 256 scan-doubled, 512, 1024 interlaced nominal
             282 scan-doubled, 564, 1128 interlaced overscanned

50Hz vertical refresh, 29.4kHz horizontal refresh


>--
>--------------------------------------------------------------------------
>|   _-_|\   | Corey Banks.         |   "Ever feel like your going up the |
>|  /     \  |                      | down esculator?"           - u4ia.  |
>|  *_.-._/  | banks@murdoch.edu.au |-------------------------------------|


-- 
---------------------------------------------------------------------------
Spencer Shanson - Amiga Software Engineer     | email: spence@commodore.COM
                                              | or uunet!cbmvax!spence
All opinions expressed are my own, and do not | Bix: sshanson
(necessarily) represent those of Commodore.   | I want a tube of
                                              | orange Smarties!
Newsgroups: comp.sys.amiga.graphics