Hope you don't mind me cross posting from Vogons, but I hadn't had any replies there to this and thought there might be peeps here with more insight into my VGA problems....
Hi all,
I've been testing a Trident TVGA9000i graphics card in my Xi8088 based computer, the https://github.com/moogway82/XTjr and it is doing some weird stuff.
Details on the card are:
Trident TVGA9000i-3 based with a 4.01E ROM. In an 8-bit ISA slot with jumpers set for 8-bit mode and Non-Interlaced modes. 256kb RAM. Electrolytics caps have been replaced as some seemed marginal on testing.
Firstly, as you can see in videos, it's detecting the display as Monochrome, but I'm not too worried about that at the moment as it's something to do with Pin 12 Monitor ID and I can work-around it using SMONITOR utility, it's been discussed here before (Problems with 8-bit TVGA9000 based ISA video card). [Aside: I had to GND Pin 12 as left floating machine wouldn't boot at all... I thought N/C Pin 12 would normally be the indicator for a colour monitor? Maybe this is a sign of a bad TVG9000i chip?]
The BIG issue I have at the moment is it locking up and DOS text is not scrolling vertically. When you get to the bottom of the screen, the machine just hangs. The boot process also doesn't scroll and just does a weird text cursor jumping around thing and lots of hidden and missing text - only XTIDE and Vid BIOS show text until SMONITOR and SVM in autoexec.bat run. I put the missing text down to monochrome being detected maybe, but the text screen scrolling issue is weird and super annoying.
Video showing the Boot Process and DOS crash:
Short Video showing just the crash in DOS on scroll
I can still run some programs however. The SVM utility for Trident cards to change the video mode works great and lots of the modes work fine when returning to DOS, however all hang when you reach the bottom of the screen. Prince of Persia's SETUP program works fine and the game runs great in VGA mode - I just get a black screen in CGA, and EGA mode. When exiting back to DOS, the machine hangs with a Black Screen. (I'm assessing machine-has-hung by whether it will soft reset Ctrl+Alt+Del). "E" PC-DOS's Edit replacement, runs fine too.
Video showing Prince of Persia running then crash on Exit:
TOPBENCH will show a grey screen and a flashing cursor on the left side of the screen 2/3rds down and hang.
Video showing TOPBENCH crash:
I've tried some of the other jumper settings on the card: 8/16-bit Memory use BIOS detect and Non-Interlaced and Interlaced, but seems to make no difference. Also, the computer works great with my 2 working EGA cards, no weird scrolling crashes there. I don't have another VGA card to test with yet.
I'd be really interested if anyone has seen something like this before with an old 8-bit PC with an ISA VGA card in DOS?
My XTjr has no DMA or 2nd PIC (no IRQs above 7). I'm sure DMA isn't a problem, not sure about 2nd Intterupt Controller, but pretty sure old VGA cards didn't do much with IRQs (IRQ 2 maybe).
My suspects are:
- ROM version, would like to try the 3.51 version, maybe 4.01E expects too much from the hardware of my XTjr? [update: got a new EPROM on order, hoping to give 3.51 a spin soon]
- RAM - only has 256kb and maybe one of the banks are wonky (although surprised PoP works so well if that's the case...)? [update: also got some DRAM on order try upgrading to 512KB - or replacing existing]
- Bad TVGA9000i-3 chip - nowt I can do at that point but surpised that it still works so well in PoP VGA mode, but terrible in Text mode
Any thoughts are greatly appreciated, many thanks!
Cheers,
Chris.
Hi all,
I've been testing a Trident TVGA9000i graphics card in my Xi8088 based computer, the https://github.com/moogway82/XTjr and it is doing some weird stuff.
Details on the card are:
Trident TVGA9000i-3 based with a 4.01E ROM. In an 8-bit ISA slot with jumpers set for 8-bit mode and Non-Interlaced modes. 256kb RAM. Electrolytics caps have been replaced as some seemed marginal on testing.
Firstly, as you can see in videos, it's detecting the display as Monochrome, but I'm not too worried about that at the moment as it's something to do with Pin 12 Monitor ID and I can work-around it using SMONITOR utility, it's been discussed here before (Problems with 8-bit TVGA9000 based ISA video card). [Aside: I had to GND Pin 12 as left floating machine wouldn't boot at all... I thought N/C Pin 12 would normally be the indicator for a colour monitor? Maybe this is a sign of a bad TVG9000i chip?]
The BIG issue I have at the moment is it locking up and DOS text is not scrolling vertically. When you get to the bottom of the screen, the machine just hangs. The boot process also doesn't scroll and just does a weird text cursor jumping around thing and lots of hidden and missing text - only XTIDE and Vid BIOS show text until SMONITOR and SVM in autoexec.bat run. I put the missing text down to monochrome being detected maybe, but the text screen scrolling issue is weird and super annoying.
Video showing the Boot Process and DOS crash:
Short Video showing just the crash in DOS on scroll
I can still run some programs however. The SVM utility for Trident cards to change the video mode works great and lots of the modes work fine when returning to DOS, however all hang when you reach the bottom of the screen. Prince of Persia's SETUP program works fine and the game runs great in VGA mode - I just get a black screen in CGA, and EGA mode. When exiting back to DOS, the machine hangs with a Black Screen. (I'm assessing machine-has-hung by whether it will soft reset Ctrl+Alt+Del). "E" PC-DOS's Edit replacement, runs fine too.
Video showing Prince of Persia running then crash on Exit:
TOPBENCH will show a grey screen and a flashing cursor on the left side of the screen 2/3rds down and hang.
Video showing TOPBENCH crash:
I've tried some of the other jumper settings on the card: 8/16-bit Memory use BIOS detect and Non-Interlaced and Interlaced, but seems to make no difference. Also, the computer works great with my 2 working EGA cards, no weird scrolling crashes there. I don't have another VGA card to test with yet.
I'd be really interested if anyone has seen something like this before with an old 8-bit PC with an ISA VGA card in DOS?
My XTjr has no DMA or 2nd PIC (no IRQs above 7). I'm sure DMA isn't a problem, not sure about 2nd Intterupt Controller, but pretty sure old VGA cards didn't do much with IRQs (IRQ 2 maybe).
My suspects are:
- ROM version, would like to try the 3.51 version, maybe 4.01E expects too much from the hardware of my XTjr? [update: got a new EPROM on order, hoping to give 3.51 a spin soon]
- RAM - only has 256kb and maybe one of the banks are wonky (although surprised PoP works so well if that's the case...)? [update: also got some DRAM on order try upgrading to 512KB - or replacing existing]
- Bad TVGA9000i-3 chip - nowt I can do at that point but surpised that it still works so well in PoP VGA mode, but terrible in Text mode
Any thoughts are greatly appreciated, many thanks!
Cheers,
Chris.