VOGONS


Packard Bell 486DX 2 66MHz VGA issue

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First post, by djgeojoe

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I have a Packard Bell 450 MB with a VGA video issue, there is vertical banding on the image only when playing games, dos and win 3.11 look fine. I installed an ISA VGA card and the issue is resolved but I want to use the on board VGA as I have installed the 1mb video upgrade to 2mb. Is it possible that the issue is caused by bad caps? if so does someone have a list of caps to replace in the video section I can try? The mainboard is a PC 4401-03 with Cirrus DG5428.

Last edited by djgeojoe on 2022-06-10, 22:19. Edited 1 time in total.

Reply 5 of 25, by Tiido

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This is a normal problem with LCDs and old video cards, there isn't much one can do about it. Sometimes a different video BIOS with adjusted display timings can fix it but that gets difficult with onboard video.

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Reply 6 of 25, by djgeojoe

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It's an LCD monitor. Thanks for the explanation on old machines. I was hoping that wasn't the issue. Fortunately I do have a Packard Bell CRT monitor tucked away somewhere, hopefully it still works and I'll give that a try and see if it rectifies the situation. I think my only other option is a VGA to VGA video processor to filter the signal (if that is possible but it would most likley add video latency). I do have a VGA to VGA signal processing board and tried it but the timings would have to be slower on the input or I'd have to make more adjustments to the adapter because it wasn't passing the video through I think it was because the resolution was too low or perhaps the signal was too distorted from the vertical lines. I'm sure there's a VGA to VGA board out there that does video processing to stop the signal spikes that are causing the LCD to band the image vertically I was just hoping this was something I could rectify on the main board video. The strange thing is that I have a cirrus logic ISA video card and it's not producing the banding, so I was hoping it was something I could rectify on the motherboard video section.

Reply 7 of 25, by djgeojoe

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Also the ISA video card is so much slower than the on board video, it doesn't seem to affect most of the DOS games I am running but it also only has 1MB where the on board has 2MB (upgraded with zip sticks) but I think the only benefit from more memory would be more colors in windows.

Reply 9 of 25, by djgeojoe

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Ok so with the ISA VGA card everything looks fine windows and games, on the main board video everything looks fine in windows (640x480) but is causing vertical lines in DOS games (720x400)

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Reply 10 of 25, by djgeojoe

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I guess my issue is I just don't understand how the Onboard video could be having a problem when playing DOS games but in a Windows or a DOS prompt environment it looks perfectly fine. There are some more settings in the Bios I will try

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Reply 11 of 25, by pentiumspeed

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Does not matter and this is not what you are looking for. Other posters are correct about these, hence the Gona's chart is the good reference. Try Trident 8900C or D with full 1MB ISA instead they are not too slow as long as this both items criticals are met. Other option highly recommended is Western Digital WDC90C30 or 31 but must be full 1MB fitted, good price for performance and compatibility is good. Doom ran rather well on these.

And other option is Oak OTI087 again 1MB too.

By the way: S3 based ISA is expensive and rare and 805 and 911 is slow. One I never considered is based on reasons: Tseng ET4000 and All ISA based on ATI chipset are slow and not too good compatible, expensive. Back in the day, I had ATi Ultra ISA bought on recommendation by someone and was slow and not compatible.

Cheers,

Great Northern aka Canada.

Reply 12 of 25, by djgeojoe

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Not sure if this helps, would upgrading the Bios to video version 1.4 help or would that open up a can of worms with the BIOS battery beeping error?

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Reply 13 of 25, by djgeojoe

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Oh and this is how I fixed the CMOS battery... yea I know but liquid electrical tape helps 😉

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Reply 14 of 25, by pentiumspeed

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BIOS firmware have no bearing on video chipset, the issues depends on some specific chipset for example 5428 and 5429 are same cores but 5429 had windows 3.11 acceleration added. Like others said it is common on specific video chipset, this is why gona's compatibility list shows the issues would do with video modes.

Matter of trying different video cards I listed above. I chose them based on how easy to get and less dependent on cost as they are always expensive for some especially ISA cards but there are some good deal to find from time to time.

And I play with LCD monitors too since all the CRTs we had decades ago was worn out from heavy use.

Cheers,

Great Northern aka Canada.

Reply 15 of 25, by djgeojoe

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Thanks man, look at this, using my NEC MultiSync LCD1970NX ( that I use for my Amiga 500 because it has the 15 khz timing) shrinking the horizontal lines on the image fixed it and there's no more vertical banding but the image is slightly shrunk on screen. I think it's time to dig out that CRT Monitor and see if this is just a modern LCD display issue or if there's something wrong with the on-board video itself. Like I said other is a video cards had a perfect image it's just the onboard that's being a PITA.

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Reply 16 of 25, by djgeojoe

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Ok so I used a video converter and it fixed the vertical lines... SMH

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Reply 18 of 25, by djgeojoe

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Yep, it's a CRT vs LCD incompatibility! It looks absolutely perfect on the old CRT

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Reply 19 of 25, by pentiumspeed

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Your video converter, does it introduce a lag in the video output when you play doom? This is one of many reasons I watched this vogons forum had to go through this before. Very, very rare solutions exists. The easiest way is use CRT monitor but aging and space and cost of shipping is one of many issues too.

Another issue is 70hz support also introduces frame skip in any scalers and LCD monitors. Ones that can handle 70Hz is very rare or non-existent.

HDMI monitors is worst way to go, 60hz only. DVI and displayport are more flexible.

Cheers,

Great Northern aka Canada.