Help with Geos resolution in Raspberry pi

I have a raspberry pi in which I run Geos in dosbox. I use the 7 inch rather old official screen with 800x480 resolution. I can only get Geos to run in vga 640x480. Prevously, I managed to run in 800x600 and use the screen settings in geos.ini to set the resolution to fit the screen. I fail to set it properly now, anyone here who made it?

I think I have found an explanation, the overscan is disabled in rpi os bookworm. I will investgate further, any input is appreciated

Quote from jpolzfuss

Isn’t there a specific driver for 800x480?

https://github.com/bluewaysw/pcgeos-basebox/issues/3

Yes, but it is not supported i.n DOSBox. The only working video mode in DOSBox is 848x480, and it is supported in Geos, but the chipset in the pi is not supporting it.

The pi os creator have also changed from x11 to wayland, since wayland have problems with overscan, overscan is turned off.

Quote from jpolzfuss

Isn’t there a specific driver for 800x480?

https://github.com/bluewaysw/pcgeos-basebox/issues/3

Can also add that the creators of DOSBox Staging, scrapped the 848x480 video mode, only 4:3 modes are available. 848x480, was the only wide format in DOSBox. I use it on my tablet and mobile phone to run Geos on these devices. i use DOSBox Turbo, but sorry to say that the creator have ended support for it.

I will test the video modes in the DOSBox to see if mode 200 is supported. I doubt it, as I get an error message in Geos when I try that mode.

I have now checked the Trio S3 emulation, the VGA resolutions supported are 640x480, 800x600, 1024x768, and 848x480. This is valid for all the DOSBoxes versions, except Staging, were the developers removed the 848x480 support.

Yes the problem is the missing support for 800x480 in DOSBox. But, I have a vague memory.that I could manipulate pi os and use the 800x600 driver, and adjust the screen in geos.ini. I can not remembee, how I did it.☹️

Well, it.is possible to revert back from wayland to x11, and run the resolution in a window. I have found an earlier discussion here with Tomas Hass. But, there are new way to handle the monitor in bookworm, it checks the monitor resolution so it is not extended beyond 800x480. If so, an irritating error message is displayed. Using the window way to solve the resolution affects also other DOS apps, if you using anything else that Geos. So the only proper way to solve it properly is to have a 800x480 resolution in DOSBox. I have also noticed a phenomenum in DOSBox, if you set the screen to 800x480, it actually shrinks the screen image a little bit, compared to use the setting =desktop, and let DOSBox "determine" the actual surface. I have decided to stick with the 640x480x64k resolution, it is the least bad thing in my setup, as it plays well with my DOS apps and games. I have also noticed a bug in the keyboard handling, which was solvable by remapping the actual keys in the keyboard mapping in DOSBox. I will check if the bug is in Basebox, too, and solveable in the same way. Consider the resolution thing solved, for the time being.

The problem is the lack of support for different VESA modes in DOSBox in general, this also applies to Basebox, which Falk have plan to solve in Basebox. Scitech Display Doctor, version 6.53, works in DOSBox and adds more resolutions, however onlyn 4:3 and 5:4 resolutions. The only 16:9 resolution which is available in DOSBox is 848x480. Other more modern like 800x480 and 1024x600 is not available, at least at the moment. 848x480 have been omitted from DOSBox Staging/Basebox.

Nothing wrong with PiGeos, except that I got some performance problems with my Pi 3B and PiGeos. The problem is the Pi 3B, too weak hardware platform, the performance was sluggish when I tested PiGeos. However, I might have done something wrong?

The best performance I have got is Pi OS lite (Bookworm 64 bit) and DOSBox 0.74-3. This combo run as expected with good performance. Why am I so pesistant in this, I can just toss away the 3B and by a 4 or even better? The thing is that I have a complete computer, 3B in a shell with a monitor, and the computer is not upgradeable

But I will give it another shot. Thanks for the link to DOSBox, will try it if PiGeos will not work as expected.

Yes, I noted that I have to build another flash with 32-bit pi os, if I use the DOSBox

I can add that even Basebox is running slooow on a Pi3B. My guess is that the PiOS Bookworm is the main cause. RPi3B is rather old, better to get a Pi4 or 5 and the new 15 inch monitor

Quote from t.hass

Pi/GEOS does still supports 800x480 resolution in DOSBox. Just checked it using the latest GEOS CI-release. If you don't like Pi/GEOS you may want to give the version of DOSBox that shipped with it a try: https://thobipix.de/download/rpi/p….74.6_armhf.deb

Please note that this is for 32bit PiOS (armhf) only and has been build on Debian 10 based legacy release.

I have installed the DOSBox you directed me to above, in a 32 bit raspberry pi os lite (bullseye). Cant get Geos to work in 800x480, is there special settings in DOSBox and pi os?

Quote from hanslse

I have installed the DOSBox you directed me to above, in a 32 bit raspberry pi os lite (bullseye). Cant get Geos to work in 800x480, is there special settings in DOSBox and pi os?

Ignore this, I found the error! An update of DOSBox overwrite the DOSBox you sent the link to. After reinstalling the DOSBox, now 800x480 works!!!

Many.thanks, Tomas!!!