Pentium 150MHz PC

Here we have a 150MHz Pentium computer, typical for late 1996 / early 1997. Soyo SY-5TF is a good mainboard with 512kB of cache and RAM in 72-pin SIMM sticks. It has COM, LPT, floppy and hard disk controllers on board. PCI slots allow to connect faster video board than these for ISA slot - here it's Trident TGUI9440.  In ISA slots, there is a SMC network card and Genius SoundMaker 18 sound card. ATA channels have attached a 850MB hard disk and a CD-ROM drive. The machine has 32MB of RAM which allow smooth operation of Windows 95.
Similar machines with 120 or 150MHz have been widely used as a better workstations for large documents, advanced text processing or multimedia, later for internet connectivity. At the same time, slower 75MHz units were extremely popular as cheap computers for pure office work. MMX was reserved for really high-end multimedia computers.
This computer has a Trident TGUI9440 PCI video card which can display 800x600 in 16-bit colour depth. However this board is extremely difficult to set up in Windows 95.

Approx. year late 1995

Class AT
CPU Pentium I
Speed 150MHz
Mainboard Soyo 5TF
Graphics Trident TGUI9440
(PCI slot)
Sound Genios SoundMaker 18
(16-bit ISA)
Ports I/O On-board,
2x COM,
1x LPT,
2 PATA channels, FDD
Probably PS/2 and early USB
Network SMC 83C759QF
(16-bit ISA)
System expansion bus 16-bit ISA (4 slots)
PCI (4 slots)
Floppy/removable media drives 1x 3.5" 1.44MB floppy disk drive
Hard disks/ATA devices: Seagate Medalist ST3850A 850MB (IDE)
C/H/S 1648/16/63

Peripherals in collection:
 - None

Other boards:


Casing Standard small AT tower
Non-standard expansions: None
Operating system(s): Microsoft Windows 95

Contents: Video board Drivers Links

Configuring TGUI9440 video board in Windows 95

 based on this article.
1. USE 5.00.28 drivers. Not newer. This driver have a glimplse of control over what the card is doing with sync.
Drivers can be downloaded in this site or in archived copy

2. After installing Win95, you will get board detected as VGA, 640x480.
3. Install your monitor first. This is really important. Use the specific model or generic type you have. Restart will be needed.
4. Now install graphics card's drivers. Restart will be needed.
Now in most cases you will get a mess on screen. Sync will not be OK. You can try different monitors, if you find one that works, you omit the next blind-typing. If you still have mess, just right-click on desktop, press keyboard cursor up and press return. This way you will open properties window.
- 6x Tab
- Arrow up
- Arrow right
- Alt-A
- Space
- Return
- "Y" (English) or "T" (in Polish Windows) or "J" (German Windows).
This is done blindly with mess on screen.
If the garbage is still there, again go to Properties window.
- 6x Tab
- Arrow up
- Arrow right
- 3x Tab (you'll land on a Refresh rate setting slider)
- Left arrow
- 5x Tab
- 2x Return
- Tab
- Return.
The idea is to disable option called "Automatically set refresh rates" in "Refresh Rate" tab which appears in Properties dialog after driver installation. After, refresh rate selection slider can be used to set the rate to minimal 60Hz. I highly recommend using decent (85Hz) display for a moment to disable automatic refresh and switch the refresh rate back to 66Hz.
The problem is that TGUI chip doesn't use standard refresh rate selection based on monitor type. There are at least 3 ways to detect which monitor is connected to the VGA output (by detecting logical states on selection lines, their responses, or serial bus on detection lines) - chip doesn't use them. So the driver assumes the maximum - 85Hz and goes with it.

But this is one of more problems with this board under Win95. TGUI9440 is one of the hardest parts of computer hardware to install.

If it appears in device manager, but with exclamation mark, it means that it usually couldn't get along with PnP OS to set IRQ number. The card works with IRQs 9 to 12. Sometimes they all must be set in BIOS to "Plug and play PCI" or "PCI/ISA PnP" to make card operating, and they must be free. Now the most interesting thing - the card just takes IRQ which is a bit contrary to PnP standard. No checking, no validation, it just takes some IRQ. If it's free, then OK, it works. If it is occupied by something other, like this SCSI controller or TV capture board, there is no way to push the card away to use different IRQ (trying to do it in Windows 95 ends with driver hanging) - so you have to free the one by moving the other device it takes. In the edge cases, when all IRQs from 9..12 range are taken, board can do even more stupid things like stealing IRQ7 from the parallel port.

Another thing is if you install it in computer with display containing DDC serial bus, but VGA-only monitor is installed as device. This particular configuration with DDC2B monitors may result in arbitrary rollback to some under-640x480 mode. It happens totally at random - one power-up it may be OK, another one - bummer, low resolution. It gives clue that the board indeed uses the monitor ID lines for something, but the way they are used remains unknown. I haven't found any method to fix this except changing monitor definition to e.g. Super VGA (most DDC2-capable monitors can do SuperVGA) or replacing monitor.





Genius SoundMaker 18 driver for Windows 95 and 3.x
Trident TGUI9440 driver version 5.00.28, for Windows 95 and 3.x
Soyo 5TF BIOS updates
Soyo 5TF Manual





Links: - possible to download latest BIOS build 1114 from 1997.