MiSTer FPGA Forum

I'm hoping to get some help from the AO486 core experts.

I've been able to successfully load several DOS games, but the video is messed up and I don't seem to be able to resolve it. The games seems to play OK otherwise. I'm only using HDMI connected to a Samsung HDTV (Although in the photo the MiSTer is connected to a cheap RCA TV for troubleshooting).

I have no problems with the video on any other core, including several computer cores. I usually use the Sony Trinitron video processing preset on most cores.

Not sure if I need to make a change to the MiSTer .INI file, reinstall, or just give up.

Any suggestions gratefully appreciated

I had this.

I’m pretty sure a few tweaks to the autoexec.bat freed up enough base memory to get them working properly. I think I had to tweak EMS / XMS settings too iirc.

Thanks Lloyd. I think your suggestion got me pointed in the right direction.

I'm using the DOS 6.22 Startup Menu. I tried each option and found that the games will run with good video if I select the "conventional memory only" option. All the other Startup Menu options including "conventional memory only + mouse" will cause the video to be messed up. I guess I should double check the changes I made to the autoexec.bat file. I may have messed up. I had been following Lu's Retro Source YouTube video for setting up the core.

I was getting some really weird video results from using outdated BIOS files. They don't get replaced when they get updated; you have to manually remove them. Try backing up and removing all the .rom files in the AO486 dir (should be three), as well as the 'drv' directory. Then run your updater, and new versions should magically show up.

Your video might work correctly after that.

Thanks for the suggestion, Malor. I think my BIOS files were OK.

Ultimately I decided to use Flynnsbit Shareware VHD as a starting point. I replaced most of the shareware games on the VHD with DOS games I wanted to try, which I extracted from eXoDOS and converted with eXoConvertor. This approach worked best for me. I did have to modify some of the start.bat files that are created to get some games to run. (EXAMPLE: one of the game executables was located on the CD but the original start.bat file assumed the CD was assigned to F:\ but when it was actually assigned to D:\ on the original Shareware VHD. Changing this in the start.bat file allowed the game to run)

I've made a DOS Schmup and a DOS Pinball VHD using Flynnsbit Shareware VHD as the starting point. It seems the best way for me to play the games as my DOS skills are quite rudimentary.

Mac users used to sneer at DOS users for how much knowledge was required to run games. They were right, but, hey, at least we had games.

Ha ha, true that Malor. I did start as a Mac user, and only got my first PC when Windows 95 came out. Now I seem to need one of each.

FWIW, it probably would have been easier back then. The AO486 core is troublesome.