Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: DamageX on July 18, 2005, 02:31:53 AM
-
I have an RGB to NTSC converter and Commodore 1702 monitor. Some games and demos display too many lines and the edge of the display (mostly the bottom edge) goes off the screen (and there are no controls for vertical size/position).
I also have a TV tuner card in a PC which has a slightly larger display area (but still not big enough) compared to the 1702. That only works for programs that are still 60hz though, programs that switch to 50hz make a mess of the TV tuner's display. I can configure it as a PAL tuner in which case the whole screen is clearly visible but it then also expects a PAL chroma signal so the color is buggered up.
Any workaround for this sort of thing? (I really don't want to buy more hardware)
-
Should be a simple solution. Connect the Amiga to the 1702. If you've got kickstart 3.x, hold both mouse buttons to bring up the Early Startup Control and change the display to PAL.
If you don't have Kickstart 3.x, run Degrader (http://www.aminet.net/package.php?package=util/misc/Degrader.lha) first. Select 50Hz and 50HzSystem, hit the SurviveResets button and you're ready to go.
-
It sounds like you're on an A500. The advice you've been given will work on an A1200 but I'm not so sure if the features of Degrader will work on an A500 so well.
AmigaToPAL (http://main.aminet.net/util/boot/AmigaToNTSC.lha) will patch your system so it will open PAL screens on your 1702 monitor. I doubt it will work on your PC's TV card if it's set to display NTSC video only. Note also that you need an ECS or AGA chipset Amiga to display PAL mode on an NTSC Amiga. (Many A500s shipped with the Fat Agnus chip but not the Super Denise chip.) The only way to find out is to try the respective patch. (The patch linked above comes with two patches, one for patching an NTSC Amiga to PAL and the other to go the reverse direction.)
-
It's an A2000 with ECS agnus and normal denise. I have kickstart 3.1 and can select pal mode from the boot menu but it doesn't fix the vertical size of the display. So are you guys saying that it would display correctly (on the 1702) if I had ECS denise?
-
Your monitor should have a vertical adjustment wheel (or potentiometer), either accessible externally (look at the backside) or internally. Alternatively, get an RGB monitor such as the C= 108x or Philips 88XX series, that can't be too difficult.
-
DamageX wrote:
It's an A2000 with ECS agnus and normal denise. I have kickstart 3.1 and can select pal mode from the boot menu but it doesn't fix the vertical size of the display. So are you guys saying that it would display correctly (on the 1702) if I had ECS denise?
That's right. A normal Denise chip can't switch scan rates therefore you can't switch it from NTSC to PAL mode unless you get a Super Denise.
-
I'd get a Microvitec 1701 or 1764 - a nice 15Khz Amiga branded 17" CRT with adjustable screen sizes!
Failing that, is it possible to access Sys:Prefs/Overscan to scale things down a little? I know this won't affect games but it'd help with Workbench (/Apps).
It's easier for PAL users as NTSC will be a squashed image but with everything still visible, with NTSC you get a taller image that goes over the viewing area (since PAL is 17.5% taller in terms of pixels).
I remember Fairlight made some `cracktros' with a built in NTSC/PAL switcher (they even did one for Wipeout 3 on Playstation!) - this makes me wonder why there isn't a program to install a boot selector onto the bootblock of floppies. Must be possible!
:-)
-
Hyperspeed wrote:
I remember Fairlight made some `cracktros' with a built in NTSC/PAL switcher (they even did one for Wipeout 3 on Playstation!) - this makes me wonder why there isn't a program to install a boot selector onto the bootblock of floppies. Must be possible!
:-)
It is. (http://main.aminet.net/util/misc/SwitchInst130.lha)
-
I got an ECS Denise but 50hz games and demos display exactly the same as they did before :(
-
There are only two Denise types: OCS and ECS - it doesn't care whether NTSC or PAL (see BBoAH (http://www.amiga-hardware.com/showhardware.cgi?HARDID=1457)). Horizontal scan rate is exactly the same (well nearly, the crystal differs) and vertical scan rate is taken care of by Agnus.
When you're working with the CVBS signal (one signal only, mostly RCA jacks) PAL and NTSC do completely different color encoding. The RGB -> NTSC converter probably outputs NTSC style color, regardless of frequencies, but the TV tuner expects PAL colors when fed with 50 Hz pictures, that's why it's b/w. Sorry, apart from using a different/PAL compatible RGB->video converter there's no way around it.
I'm having the same type of problem when trying to digitize NTSC videos here in Germany: I've got an 'NTSC playback' VCR, that recodes the tape's NTSC to PAL and outputs with 60 Hz (='PAL 60'). All video cards I've tried expect an NTSC color code and won't see the PAL color. The only way out is a real NTSC VCR.
PS: I've bought a genlock at eBay to convert Amy's RGB to PAL SVideo - much better picture than CVBS and cheap. :-)