Short: Force A2024 monitor driver to NTSC/PAL Author: markk@clara.co.uk Uploader: markk clara co uk Type: driver/moni Version: 0.1 Architecture: m68k-amigaos Patches for A2024 monitor driver to force NTSC or PAL operation =============================================================== Version history --------------- 2012-03-28 0.1 First release. Please report any problems! About the A2024 --------------- The Commodore A2024 is a high-reolution 15" grey-scale monitor which contains a special scan converter board. The same circuitry was also available on a card for the A2000/3000/4000 video slot, for connection to a Moniterm high-res monitor. You can see pictures of the A2024 at http://www.amiga-hardware.com/showhardware.cgi?HARDID=863 The Moniterm scan converter card can be seen at http://amiga.resource.cx/exp/moniterm The scan converter builds a high resolution image from four or six Amiga fields. When connected to an NTSC Amiga, the A2024 can display a 1024×800 pixel screen in 2 or 4 colours (black and white, or black, white and two shades of grey). Connected to a PAL Amiga, the A2024 display is 1024×1024 pixels. The A2024 driver code limits the display width to 1008 pixels on machines with the original (non-ECS) Agnus chip. The A2024 is compatible with any Amiga which has a 23-pin video port, even the Amiga 1000 and CDTV. It does not require a particular CPU or chipset. A2024 support is built into version 2.0 and later of the Amiga OS. The A2024 came with a special "Jumpstart" disk to enable A2024 modes under Kickstart 1.2/1.3. The ability to use A2024 modes is not limited to OS-legal software. Some software which does not run under the Amiga OS also supports A2024 modes, for example: · Amiga UNIX · The A-Max Macintosh emulator (ReadySoft) · NetBSD While only a few people today have a working actual A2024 monitor, the WinUAE Amiga emulator includes emulation of A2024 modes from version 2.4.0. That allows a nice high resolution Workbench without needing RTG software or a faster emulated CPU (the Picasso96 RTG software requires at least a 68020). It also allows a high-res desktop with the A-Max Macintosh emulator. About the patches ----------------- The patches are only of use on machines with the ECS Agnus or AGA chipset. The original A2024 driver uses a 1024×800 display on NTSC machines, and 1024×1024 on PAL machines. The patches allow you to create modified versions of the A2024 driver, which always use 1024×800, or always use 1024×1024, regardless of whether your Amiga is PAL or NTSC. There are several reasons why you might want to force the A2024 driver to work in a particular mode: · The pixels of the "NTSC" 1024×800 mode are almost square on a 4:3 monitor, whereas the pixels of the "PAL" 1024×1024 mode are wider than they are tall. If you have a PAL Amiga, you might prefer the almost-square pixels in 1024×800 mode. · The A2024 monitor screen has a 4:3 aspect ratio. When using the 1024×1024 mode, the mouse pointer is more sensitive in the vertical direction. (For a given distance of mouse movement, the pointer moves by more pixels vertically to move the same physical distance, compared to horizontal movement.) When using 1024×1024 mode with an emulator which displays the pixels 1:1, the mouse pointer moves faster vertically than it does horizontally. With the 1024×800 mode, the difference in vertical pointer speed is lower. · If using an emulator on a computer whose monitor resolution is 1280×800, 1440×900 or 1600×900, the full PAL 1024×1024 display will not fit on the screen. Even with a 1680×1050 monitor, showing a full 1024×1024 A2024 screen might not be possible due to the taskbar and window borders. · If your emulated Amiga is NTSC and you use a 1280×1024 or larger monitor, you might want the A2024 display to be 1024×1024 instead of 1024×800. · If you have an NTSC Amiga and a PAL-model A2024 monitor, or vice versa, you might need to force the A2024 driver to work in the correct mode for the monitor. (Can someone with a real A2024 confirm whether or not that is necessary?) How to apply the patches ------------------------ These patches apply to version 43.9 of the A2024 monitor driver, as included in the AmigaOS 3.5 Boing Bag 1 update. It is probably also on the AmigaOS 3.9 CD. That version remains compatible with Workbench 3.1. As far as I know, version 43.9 was the final version of the A2024 driver. Included in this archive is copy of GPatch 3.0, which is copyright © 1997- 2002 Ralf Gruner. You can get the full GPatch distribution from Aminet, util/misc/gpatch.lha To apply the patch, in a CLI/Shell window use a command like this: GPatch A2024 A2024_43.9_force_NTSC.gpch RAM:A2024_NTSC or GPatch A2024 A2024_43.9_force_PAL.gpch RAM:A2024_PAL To revert the patched file to its original state, use a similar command: GPatch RAM:A2024_NTSC A2024_43.9_force_NTSC.gpch A2024_original or GPatch RAM:A2024_PAL A2024_43.9_force_PAL.gpch A2024_original Once you have your patched monitor driver, move the original A2024 driver out of DEVS:Monitors (e.g. to SYS:Storage/Monitors), and copy the patched driver to DEVS:Monitors. Remember to create an icon for it, e.g. copy A2024.info to A2024_PAL.info. Since the patched drivers act exactly like the original, you can only have one active each session. So if you first run the PAL-patched A2024 driver, in order to use either the NTSC-patched or original driver you need to reboot and run that driver.