taab5@ccvax.iastate.edu (Marc Barrett) (01/14/91)
In Message <1419@tardis.Tymnet.COM> <jms@Tardis.Tymnet.COM> writes: >>Question: What display modes does the Amiga have? >Answer: Lots. I took the table given in the original message, and altered it to make it a little more sensible. The following table is a list of the resolution modes possible with a 'normal' Amiga (without the Enhanced Chip Set). The 'NTSC' and 'PAL' categories indicates the resolutions possible in NTSC and PAL. The 'BitPlns' category indicates the maximum number of bitplanes possible in each resolution mode. To find the maximum number of colors, take 2^(Max. Bitplanes) Mode (Normal Denise) NTSC PAL BitPlns Palette ------------------------ -------- -------- ------- ------- Lores 320x200 320x256 6 4096** Lores-Interlaced 320x400 320x512 6 4096*,** Hires 640x200 640x256 4 4096 Hires-Interlaced 640x400 640x512 4 4096* The Super Denise (in the ECS) has all of the resolutions in the previous table, plus the added resolutions in the following table. Note that this is a very incomplete table, as literally hundreds of resolutions are possible by fiddling with the programmable scan rates of the Super Denise. Mode (ECS Super Denise) NTSC PAL BitPlns Palette ------------------------ -------- --------- ------- ------- Super-Hires 1280x200 1280x256 2 64 Super-Hires-Interlaced 1280x400 1280x512 2 64 VGA-ExtraLores 160x480 same 6 4096** VGA-ExtraLores-Interlcd 160x960 same 6 4096** VGA-Lores 320x480 same 4 4096 VGA-Lores-Interlaced 320x960 same 4 4096 Productivity 640x480 same 2 64 Productivity-Interlaced 640x960 same 2 64 A2024 1008x800 1008x1024 2 16*** Notes: All of the Amiga's resolution modes can be extended somewhat by use of overscan, with some extendable to a greater extent than others. The non-ECS resolutions can typically be extended by about 17% by the use of overscan, while the added ECS resolutions can only be extended by about 5% by the use of overscan. * The Display Enhancer in the Amiga 3000 (and the Display Enhancer Board for the Amiga 2000) will de-interlace all of the interlaced resolution modes of the first table, as well as any interlaced-and-overscanned resolution modes. It will not, however, de-interlace any of added ECS resolution modes. ** The Lores and Lores-Interlaced modes can display 64 or 4096 colors (out of al palette of 4096) the Extra-HalfBrite (EHB) and Hold-And- Modify (HAM) resolution modes. Both of these use 6 BitPlanes. (I believe that the VGA-ExtraLores and VGA-ExtraLores-Interlaced are also capable of EHB and HAM modes, but am not certain about this) The 2nd 32 colors of EHB mode are restricted. They are the same as the first 32 colors with the red, green, and blue values reduced to one half. HAM mode (Hold And Modify mode) allows all 4096 colors to be displayed, but has restrictions affecting adjacent pixels of differing colors. *** The Commodore A2024 monitor is a gray-scale monitor. In the maximum resolutions given in the table, it displays a maximum of 4 shades of gray out of a palette of 16 shades of gray. This monitor requires the ECS, and so is listed with the ECS resolution modes. To answer a question from Dennis_Grant@CMR001.BITNET in message <910112.21331533.053294@CMR.CP6> about the resolution modes possible with an A2000 with the ECS, with the A2432 Display Enhancer Board, and with both: An A2000 with the ECS can display all of the resolution modes given in both tables, including both the NTSC and PAL resolution modes. An A2000 with the A2432 but without the ECS can only display the resolution modes in the first table. In addition, it can display these resolutions in either NTSC or PAL, but not both. With the A2432 active, all of these resolution modes are non-interlaced. An A2000 with both the ECS and the A2432 can display all of the resolution modes given in both tables. In addition, with the A2432 active, all of the resolution modes in the first table are non-interlaced, in both PAL and NTSC. However, the A2432 will not de-interlace any of the ECS resolution modes in the second table (as I said in the first set of notes), so with the A2432 active all of the interlaced resolutions in the second table will still flicker. -MB-