Windows 10 BIOS startup resolutions

[devtty0]

Hey,

I've got my BIOS dialled back, so its just a brief screen, but its still there, and the first phase of the windows 10 boot is 800x600, and I cant seem to find how to disable or change that.

does anyone know of any BIOS which only supports 640x480, or a way of hiding / changing that initial Windows 10 resolution? I'm worried about damaging the monitor.

I've seen mention of some custom hardware solutions to display showing the VGA signal for the first 10 seconds or so, but I've not seen any diagrams or how you would actually go about that

cheers

 

[big10p]

ATOM-15

https://geedorah.com/eiusdemmodi/forum/viewtopic.php?id=64

Only for certain cards though, I think.

big10p2021-06-21 10:19:19

 

[davey d]

I think If you use a J-pac they can be setup to only allow a 15khz signal through to the arcade monitor?

 

[devtty0]

31khz for me, so the J-pac isnt an option - that Atom looks interesting - need balls of steel to run that against a decent card though!

 

[big10p]

You have a 31khz monitor? That should be ok for windows anyway, surely. Also, the jpac has jumpers to set 31khz.

 

[devtty0]

Windows 10, the initial boot phase (prior to the login screen - and I have auto-logon set) displays at 800x600, before the custom resolution (640x480) is applied

looks like the j-pac, with a vga breakout connected to the j-pac jamma edge is the best way then?

so:

pc -> VGA cable -> -pac -> jamma connector/fingerboard -> vga breakout cable -> vga to naomi monitor

bit of a faff, but should work fine!

devtty02021-06-21 12:26:41

 

[devtty0]

I ended up ordering a GBS 8220 - only £20 from china, so much cheaper than a j-pac, and has vga connectors, so less faff

apparently you can set the output resolution to 640x480, so hopefully it will either downscale (unlikely) or not display (hopefully) the higher res boot signals.

When it gets here, I will update how it goes.

 

[devtty0]

the GBS 8220 was a bust unfortunately - couldnt handle 640x480 on the input, despite outputting that resolution ok.

so:

pc -> VGA cable -> -pac -> jamma connector/fingerboard -> vga breakout cable -> vga to naomi monitor

it is!

 

[devtty0]

hmm .. the jpac isn't syncing with the PC - its just set to 640x480 atm - displays fine on the arcade monitor - but the 'sync ok' light on the jpac is very much not on, with a bright 'sync' light only.