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8bit Friendly ISA VGA cards

Tronix

Experienced Member
Joined
Dec 14, 2012
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135
Location
Russia, Moscow
Today i booted system with CGA video card and non-working VGA Trident TVGA9000C card together. I was able to dump ROM bios from C000h segment to disk and copmpare it with original BIOS. Dump similar to original BIOS but contain 0xFF bytes at random locations. Every time when i make new dump 0xFF bytes changed locations. I am not discovered dependings. Random places, random 0xFF bytes. Of course, calculated checksum of dump never matches to checksum of original ROM. So, i think it's totaly hardware problem around TVGA8900D and TVGA9000C chips. Maybe, to remedy the situation the presence of buffer like 74LS245 on the data bus, i am not sure...
 

giobbi

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Dec 23, 2012
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954
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São Paulo country, Brazil
I have a Trident with the TVGA9000i-3 chipset. It has an 8 bit/16 bit jumpers, but definitely it doesn't work neither in my 5160, nor in my XT clone, 8088 based.

I tried D4.01E and D3.51 firmware, no changes. The computer seems to boot, but there's no output signal (monitor goes into stand-by mode).
 

Trixter

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The very first post of this thread lists the chipset, so it might work.

All ISA VGA cards do not require drivers to work for booting and normal DOS usage.
 

Jackson

Experienced Member
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Jan 11, 2015
Messages
328
Location
Raleigh, NC
For all Olivetti M24 machines; even when jumpering both the P8 board and the mainboard to disable onboard, some cards that have compatibility like the VGA Wonder XL will simply freeze the machine with nothing to display.

SpeedStar 24X with the "16-bit" BIOS access jumper disabled (set open) will make the machine boot, but no video is shown. I'm not even sure if that card is 8-bit compatible at all, actually.
 

Jackson

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Jan 11, 2015
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Location
Raleigh, NC
Confirmed cards with no absolute compatibility for the Olivetti M24 in any way; SpeedStar 24X, Paradise VGA 16, ATI VGA Wonder XL, and the later ISA Dolch PitViper models. Even if the machine can POST and boot, you can indicate whether the video card is actually found if there is a beep after all the startup tests have succeeded.
 

evildragon

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May 29, 2007
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1,645
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Tampa Florida
Confirmed cards with no absolute compatibility for the Olivetti M24 in any way; SpeedStar 24X, Paradise VGA 16, ATI VGA Wonder XL, and the later ISA Dolch PitViper models. Even if the machine can POST and boot, you can indicate whether the video card is actually found if there is a beep after all the startup tests have succeeded.

You might be able to get the VGA Wonder XL to work actually. If you put it in another computer that it works in, there's a configuration utility on the original driver disk that sets the bit width of the IO and ROM BIOS of the card. I wonder if that would help, it did with my model 25. It saves that data into NVRAM on the card.
 

sergey

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Jul 15, 2010
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734
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Silicon Forest, Oregon, USA
Trident TVGA8900* and TVGA9000* cards will not work in the original IBM PC, the original IBM XT, and some clones. This is because these cards rely on ALE signal to latch the memory address, and the IBM PC/XT boards have a bad habit of pulsing ALE signal during DMA cycles (including memory refresh cycles), while DMA provides the address on the ISA bus. The issue, and the workaround are documented in this thread.
 

sergey

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Silicon Forest, Oregon, USA
Trident TVGA8900* and TVGA9000* cards will not work in the original IBM PC, the original IBM XT, and some clones. This is because these cards rely on ALE signal to latch the memory address, and the IBM PC/XT boards have a bad habit of pulsing ALE signal during DMA cycles (including memory refresh cycles), while DMA provides the address on the ISA bus. The issue, and the workaround are documented in this thread.

And, the simple workaround is to disconnect ALE signal going from the ISA bus to TVGA chip (e.g. cut the trace on the Trident VGA board), and connect it to the +5V power supply.
 

Termina

New Member
Joined
Dec 4, 2017
Messages
6
I have a 8088 PC (XT clone) and a Trident 8900C.

I get video, but always get 'Keyboard error' and my AT keyboard stops working.

When I plug back in the Paradise CGA card they keyboard works once more.

Was just curious if anyone else has experienced this, or had any suggestions. Thanks!
 

alejack12001

Experienced Member
Joined
Jul 26, 2020
Messages
298
Seeking Assistance with Paradise VGA card

Seeking Assistance with Paradise VGA card

I am seeking some help with a search to attain documentation or user recommendation for a Western Digital Paradise VGA 8-bit card and accompanying software found on line. The card has 256kB RAM and PVGA1A chip. I am using the card as replacement for the P4 card of an AT&T 6300 machine with standard 640 KB RAM. The P4 still works however the monochrome monitor bit the dust long ago. The P4 card has been disabled by use of the removal of the 74LS00 chip and shorting of the pins as described in the AT&T service manual. Right now, with the PVGA1A switch settings are OFF, I can see in color CGA, however, I am seeking VGA, if possible. Switch settings SW1-1 and SW1-2 allow for PS/2, which suggest VGA capability. However, I have yet to try them. There are four config files are listed ISAA201.CFG, ISAA201A.CFG, ISAA20FG, and ITCC0210.CFG. I would assume the ISAA201.CFG or ISAA201A.CFG is applicable to my PVGA1A card for the config.sys file. The executables are PARADISE.EXE, VESA.EXE, VESA1A1B.EXE, VESA1C.EXE, VESA1D.EXE, and VESAX.EXE. I have tried both PARADISE.EXE and VESA.EXE. Both put some commands in RAM. The assistance being sot would address the four config files, six executables and any switches associated with them along with which of the config files are associated with these executables.
 

Trixter

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I'm somewhat confused by your results: You have a VGA (PVGA1A chipset) card installed, connect to a VGA monitor, but you're only able to init and see CGA modes? What happens when you run a program that supports 256-color VGA graphics?

All of the *.cfg files have nothing to do with config.sys; I'm not sure what they are. The .EXE files are various VESA support TSRs, and PARADISE.EXE allows you to test and configure the card including forcibly set strict CGA compatibility -- however doing so *limits* you to CGA, so don't run that if you're trying to run VGA programs. You should only force the card into CGA-only compatibility if you're trying to run a program from before roughly 1986 and the graphics/display isn't working right.

A picture of the card would help identify it.

If you don't have a program that you know supports 256-color graphics, run DEBUG and type the following, hitting ENTER after every line:

Code:
a
mov ax,0013
int 10
ret
(hit enter twice here)
g

This should clear the screen to a VGA mode, and then in lower-res 40-column text, you should see debug print "Program terminated normally (0000)". If the screen does not clear, then something is wrong.
 

Eudimorphodon

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Joined
May 9, 2011
Messages
5,102
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Upper Triassic
Since this thread has returned from the dead I'll toss in a compatibility test result: I have three OAK OTI077 ISA VGA cards that I've tested will work in a Tandy 1000 HX motherboard using a Plus to ISA slot adapter:

attachment.php


The only thing that doesn't work is the VGAMODE program OAK uses to set backwards compatibility modes (CGA/Hercules), which hangs the machine if you try to select one of those options. (Setting VGA screen modes like the extended text modes works fine, it's only the things that try to force register compatibility with non-VGA cards that blow up.) I suspect this is a Tandy-specific quirk but I don't have a generic XT to confirm. Anyway, this suggests these might be usable cards for other Tandy 1000 machines, if a VGA Tandy 1000 floats your boat.

(You do need to use the "vgafix" program on the TVdog archive to tweak the BIOS data area for all software that tries to autodetect VGA cards to work properly, but that apparently applies to most cards. Also, full disclosure, I had a V20 installed, so I can't vouch 100% that these will work with an 8088)

I also have two more of these cards that *don't* work, but maybe that's a subject for another thread.

(EDIT: Actually, maybe those other two do work... I'll do that other thread.)
 
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