VOGONS


Reply 20 of 24, by douglar

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I tried the SciTech Display Doctor 6.53 universal video driver for windows 95. It detects that the video adapter is a UMC 85c418F-GP, but says that the device is unsupported. It can’t confirm memory >1MB either. It says -1KB.

I tried SNOOP.EXE too. That’s a clever utility. I got some cool info on some of the other VLB-SVGA cards that I have. But it fails when I have the UMC card in the computer. I'm following up in the SNOOP.EXE thread.

The VGA BIOS string on my card reads:

BIOS VERSION 1.05, BOARD VERSION VL-1AV Date: DRAM: 256K DRAM: 512K DRAM: 1M  11/22/93

The INT 13 portion of the driver reads:

º   VESA SUPER I/O Card Installed   º
º ROM BIOS FOR UM82C418 º
º VERSION 1.02 º
...
Press F5 if you want to run SETUP

Sometimes I think I've seen part of that text flicker across the screen at boot screen when the monitor is synchronizing, but if it is there, it is gone before the image stabilizes.

Anyone have a different BIOS I can try?

Reply 21 of 24, by clb

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SNOOP has handwritten case-by-case code to detect different ISA and ISA VLB (S)VGA adapters. This resulted in code like this based on information from the different data sheets and articles on the web.

For PCI adapters it uses a lookup from the PCI-SIG device ID database which is fortunately a generic method for all adapters.

For VESA compatible adapters it reports whatever the VESA driver outputs.

In my lab I've got a couple of dozen graphics cards that I've developed SNOOP on, though I don't have any UMC cards, so the only hope of SNOOP identifying this card is probably if it supports VESA directly from the firmware (in which case SDD and other tools will also give the same information)

If there is a data sheet for UMC cards VGA register extensions somewhere, then it would be possible to add manual detection for that UMC card there. (SNOOP has a custom mode to dump VGA registers if one wants to reverse engineer what the extended registers would mean, although that is not particularly easy task to do.. would require many example card variants/versions to make robust)

Reply 22 of 24, by douglar

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I'll take a look at the VGA registers and BIOS calls tomorrow after I dig myself out from under work.

Would SNOOP work if I get SciTech UniVBE 6.7 running?

Seems like it should work with my board but so far no luck.

List of supported SuperVGA families, and chipsets within each family:
23: UMC SuperVGA:
2: UM85c418

List of supported Ramdac values:
51: UMC UM70c188 24 bit DAC

Reply 23 of 24, by douglar

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I figured out how to do the override. I needed to tell it that it didn't have -1KB of ram and that it had a UM70c188 ramdac.

Doesn't seem to make a difference if I say 1024KB or 1536KB. I get the same screen.

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I don't know if it works or not yet because messing with the drivers back and forth hosed up my win98se install
The 512MB CF I was using was kind of tiny for a Win98SE install so I tried a larger drive. What should have been a simple matter was complicated because this loads after the MR BIOS but before whatever option rom or overlay that I add and it causes some curious failures. Been a while since I've had a set up where EZ Drive 9.09 couldn't boot.

º   VESA SUPER I/O Card Installed   º
º ROM BIOS FOR UM82C418 º
º VERSION 1.02 º

I'm going to go back to the 512MB device and do a win95 osr2 install

Reply 24 of 24, by douglar

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I got things sort of working with this configuration:

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I hooked up my old Sony Multisync and then changed the refresh to something the LCD liked and I could do 800x600x256. Seems like the clock is not right. Also Screen would glitch every time I opened a command prompt window in a way that makes me think that it doesn't have the memory configuration right. It would go back to normal if I hit alt-enter twice.

Ideally, I think you might be able to use a 2MB card if you had something like this:

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How can I tell what the clock chip is on the board?

But I expect that the UM70c188 ramdac might hold you back. Maybe it's possible to replace the ramdac with a better one?

Here's some info I found about the UMC UM70c188:

https://pdos.csail.mit.edu/6.828/2008/reading … adoc/RAMDAC.TXT

UMC UM70c188 TrueColor DACs:

REG06 (R/W): Command Register
bit 0-3 (R) Always 0
4 Set in 24bit mode, clear in all other modes
5-7 Mode: 5: 15bit, 7: 16bit. Don't care for 24bit
Note: This register can also be accessed at REG02 by reading REG02 four
times. Then the command register can be read or written at REG02.
This access will be terminated by any access to REG00, REG01 or REG03
or after a read or write of the command register. (DAC type 4-1r1w).