7500 with display resolution issues

[systemseven]

i have a 7500/100 with a sonnet crescendo G3 400/512 upgrade

i am using a scsi2sd card from a previous working 7500 system - and can boot into 9.2.2 or 7.6

when i first put the scsi2sd card in the system i booted to 7.6 and was able to set display resolution from a big selection (i am using a dell p170sf with a vga adapter)
but on restart only 640x480 is available. i booted into 9.2.2 and was able to select higher resolutions again, but upon restart, same issue - only 640x480 is available.

this 7500 has the AV module installed, but i dont think i have any extensions on control panels that allow me to access it (i didnt use a 7500 AV specific install, so i don't think it knows how to access the module?) - however the original HDD (running 8.5) that the 7500 came with had a control strip that let you select audio/video input. im wondering if there is some weirdness with the resolution selection and the AV module? i didnt have this resolution issue with my previous 7500 and this scsi2sd setup, but i also dont remember if that one had the AV module installed - but unplugging it doesn't seem to change the issue i am having.

during my trouble shooting, i disabled the ˚AppleVision extension and when i restarted i was able to select 1024 and higher resolutions again, but once again when i restarted i was forced back to 640x480 with no other choices. bit depth lets me choose up to millions of colors, but resolution is fixed. i just left applevision disabled in the meantime.

is there a utility that lets the system check vram? i am pretty sure the 4mb vram i have installed is okay, since i can display larger resolutions fine some of the time - maybe the vram access is on the fritz and only working some of the time? recapping needed?

i am perplexed...

 

[Byrd]

Hi systemseven,

I suspect it's your DB15 - VGA adapter forcing 640 x 480 resolution from startup each time, there are adapters that let you force higher resolutions. It might also be a good time for a PRAM reset, and maybe an OS reinstall.

 

[systemseven]

wow - that was totally it! i have a griffin mac pnp DB15->vga adapter, and the dips were set to "Plug and Play" all resolutions, but seems it was forcing 640x480 for some reason. set the dip switches to force 1024x768 and it seems to be reliably forcing my preferred resolution now. thanks! i'm glad i asked since i just assumed "all resolutions" was the correct setting (dont make assumptions kids)

now to figure out how to get the 7500 AV personality module working. im going to update from 7.6 to 7.6.1 later today, but im not sure that update includes anything relevant to the 7500. looked at the contents of a pre-G3 apple software restore CD, but it didnt seem to have any extensions or control panels specific to the AV module. its not really a big deal, i dont think i will be capturing video with that card, and the system already has analog audio in and out build onto the motherboard.