DOS Days

Trident TVGA8900 Series

The TVGA 8900 series was the third Trident chipset family, released in 1990 after their earlier TVGA8800 series from 1988/1989.

	Released	Early 1990
	Bus	ISA 16-bit
	Standards	MDA, Hercules, CGA, EGA, VGA, SVGA
	Memory	256 KB, 512 KB or 1 MB
	RAMDAC	External
	See Also	Trident TVGA8800 Series

The Trident TVGA8900 series comprised the following variants:

8900B (1990) - 256 KB or 512 KB video memory. Max. 72 Hz refresh rate.
8900C and 8900CX (1991) - 512 KB or 1 MB video memory, choice of various RAMDACs.
8900CL and CX2 LC2 (1991) - Slightly faster and more stable variant of the 8900C and 8900CX.
8900D (1992) - TrueColor RAMDAC, faster performance with zero wait states, faster DRAM clock, 1 MB linear addressing, max. 75 Hz refresh rate.

One of the advantages of the Trident TVGA 8900 series was its high level of compatibility with older graphics card standards. Unlike many chipsets that emulated MDA, Hercules, CGA and EGA in the BIOS only, the TVGA 8900 series ensured register-level compatibility for all these older standards.

The first of the 8900 series of VGA chipsets, TVGA 8900B, could only access 256 KB or 512 KB of video RAM. Cards based on these were not particularly fast, and they supported screen resolutions up to 1024 x 768 in 16 colours or 800 x 600 in 256 colours. TVGA8900B-based cards often came with the minimum 256 KB of memory since they were usually budget-oriented cards, but often came with memory sockets for expansion up to the full 512 KB. In September 1990, Trident added 8514/AI emulation capability to their ROM BIOS (vC3.0 and later?), giving cards the ability to run software written to the 8514/AI standard.

The TVGA 8900C followed in 1991, being able to access up to 1 MB of video RAM. These cards typically have the common "MUSIC" chip, which is an 8-bit DAC. Cards typically support up to 70ns DRAMs. BIOS versions C3.0 and C4.3 are known to be VESA 1.2 compliant. I haven't tested C3.01, C4.0, C4.01 or C4.3. Apparently, Trident BIOS version C3.xx or later on a 8900C supports Sierra HiColor DACs (SC11483 or SC11487).

Trident used the 8900C in their own card, the Impact III, which arrived in mid-1991 for a retail price of $295 for the 1 MB version, $229 for the 512 KB, or $195 for the 256 KB version. This card came with a Quadtel BIOS [like almost all of the ISA-based Trident chipsets) and a conventional VGA RAMDAC, though you could optionally buy an Edsun RAMDAC for a further $100 or a Sierra RAMDAC for $50. With 100ns memory the card was forced to run in interlaced mode at 1024 x 768, but with 80ns memory you could run at this resolution in non-interlaced mode. VESA compatibility relied on the loading of a TSR. The card also came with a utility to move the ROM BIOS into RAM (otherwise known as ROM shadowing).

The TVGA 8900CL chipset was a mildly enhanced version of the 8900C/CX. It was able to run slightly faster due to optimised internal logic. The "CL" stands for Cost-Reduced/Low Component. The 8900CL generally exhibited better stability, able to handle better timing on motherboards with erratic bus speeds. There were at least three sub-variants of the 8900CL, the TVGA8900CL-B, TVGA8900CL-C, and TVGA8900CL-D.

Aside from this, they were functionally the same as the 8900C.

The TVGA 8900D arrived in 1992 as the successor to the TVGA8900CL and TVGA8900C VGA chipset, with the key improvement being faster performance through zero-wait state direct memory writes on the ISA bus and a faster DRAM clock (48 MHz). It also added support for 1 MB of linear memory addressing (no more bank switching). It required just 3 support chips: TKD8001 TrueColor DAC/clock chip and two 256x4 DRAM chips. Maximum resolution was 1024 x 768 non-interlaced in 256 colours at 72 Hz refresh rate, or 1280 x 1024 interlaced in 16 colours. With the optional TKD8001 TrueColor DAC it was able to run up to 800 x 600 in 64,000 colours. The TKD8001 TrueColor DAC came in two flavours: a 15/16-bit variant which provided support for 800 x 600 in up to 64,000 colours, or a 24-bit variant which meant 16.7 million colours at 640 x 480 resolution. I've seen a sub-variant of the 8900D called the 8900D-R, which had a date code of late 1995 on a card with FCC ID: HNG890CL-BBD1TIA1.

Known BIOS versions for 8900D cards include C4.4 and C4.5. All the ROM BIOS' for the TVGA8900 series were 32 KB in size, held in two EPROM/EEPROM chips with high bytes in one and low bytes in the other.

Benchmarking

Back in 2021, I ran a set of benchmarks that compared the 8900CL with the 8900C, Paradise PVGA1A, ET4000, and Cirrus Logic CL-GD510/520.
Around 2024, I ran another set of benchmarks that included an 8900CL with 'fast' 70ns DRAMs against the ATI Graphics Ultra, Diamond Stealth VRAM, and Tseng Labs ET4000.

Both these tests confirmed that using faster DRAM memory is key to getting the best performance out of otherwise slower ISA graphics cards, but chipset efficiency certainly plays a part. Another point to note from my experience with Trident 8900 cards is that they don't play nicely when run on an overclocked bus. Where my ET4000 cards will happily run on a 12 MHz or higher bus, the Tridents I have fail to POST even at 10 MHz.

Video Modes

In addition to the modes found on standard VGA cards (00h-07h, 0Dh-13h), the TVGA 8900 series supported the following extended text and graphics modes:

Mode #	Text/Graphics	Resolution	Colours	Text Block/Type	Notes
50h	Text	80 x 30	16	(8x16)
51h	Text	80 x 43	16	(8x11)
52h	Text	80 x 60	16	(8x8)
53h	Text	132 x 25	16	(8x14)
54h	Text	132 x 30	16	(8x16)
55h	Text	132 x 43	16	(8x11)
56h	Text	132 x 60	16	(8x8)
57h	Text	132 x 25	16	(9x14)
58h	Text	132 x 30	16	(9x16)
59h	Text	132 x 43	16	(9x11)
5Ah	Text	132 x 60	16	(9x8)
5Bh	Graphics	800 x 600	16	Planar
5Ch	Graphics	640 x 400	256	Packed
5Dh	Graphics	640 x 480	256	Packed
5Eh	Graphics	800 x 600	256	Packed
5Fh	Graphics	1024 x 768	16	Planar
60h	Graphics	1024 x 768	4	Planar	Interlaced
61h	Graphics	768 x 1024	16	Planar	Portrait monitor required
62h	Graphics	1024 x 768	256	Packed	1 MB cards only, NI
6Ch	Graphics	?	?	?	1 MB cards only, NI
74h	Graphics	?	?	?	1 MB cards only, NI
75h	Graphics	?	?	?	1 MB cards only, NI
76h	Graphics	?	?	?	1 MB cards only, NI
77h	Graphics	?	?	?	1 MB cards only, NI

The TVGA8900B can be found on the following graphics cards:

Trident Microsystems TVGA 8916
Octek (unknown model)

TVGA8900C chipsets can also be found on the following cards:

Octek MVGA 2000-II
Trident Microsystems Impact III
Unknown card with FCC ID: HNG 8916CX248 LC2
Unknown card with FCC ID: KBI 8900CL4X256

TVGA8900D chipsets can be found on these cards:

Trident Microsystems card with FCC ID: HNG890CL
Hightech Information System Ltd (HIS) card with FCC ID: KBI8900CL4X256

Competition

In 1990 when the Trident TVGA8900 chipset first launched, the VGA graphics market was hugely competitive. Windows 3.0 was gaining traction, and impacted greatly on the consumer graphics card market. Home PC users now demanded higher resolutions and colour depths to see and use Windows in all its glory. Screen resolutions of 1024 x 768 were now the minimum standard when not playing games (which typically still ran in 320 x 200 in full-screen DOS). This was just about the limit for the average monitor at the time, which would have been a 14" SVGA on standard and premium PCs.

The same graphics card brands were there as had been over the past few years: ATI, Everex, Western Digital/Paradise, Video Seven, Genoa, Tseng Labs, and Cirrus Logic.

In the Media

Advert for Trident's 8916 series graphics cards, October 1990

"Trident Microsystems has begun shipping an extended VGA board that uses the company's own VLSI chip to minimize memory requirements for running in standard and extended VGA modes.

The TVGA 8900 Super VGA board can display up to 256 colors in interlaced or non-interlaced resolutions as high as 1,024 by 768 pixels, and supports VGA, EGA, Hercules, CGA, and MDA graphics display modes.

A 32-bit data memory bus and internal cache design on the board make it possible for the TVGA 8900 to use slower memory rather than VRAM for standard applications, according to the company. The board can support standard VGA modes such as 640 by 480 in 256 colors, or 800 by 600 in 16 colors with only two 256 KB chips. Eight 256 KB chips can support 1,024-by-768 resolution in 256 colors for non-interlaced monitors.

Drivers supporting the TVGA 8900's extended modes include those for current releases of Lotus 1-2-3, Autocad, Pagemaker, Ventura, Windows, and Presentation Manager.

Suggested retail prices for the TVGA 8900 board are $199 for the 8-bit board with 256K of RAM; $245 for the 16-bit version with 256K of RAM, $315 for the 16-bit board with 512K of RAM; and $569 for the 16-bit board with 1 megabyte of RAM. "
InfoWorld, March 1990

High-Resolution Graphics Boards review - Trident TVGA 8916 card put up against Paradise VGA 1024, Headland V-RAM VGA, IBM 8514/A, Matrox MG-108, Paradise Plus-A, Desktop Computing AGA 1024, NEC Multisync Graphics Engine, and Renaissance Rendition II. The cards were split into three categories: Super VGA (low-end), 8514/A (mid-range), and TIGA 34010 (high-end), with the Headland, Paradise VGA 1024 and Trident in the Super VGA category, IBM, Matrox, and Paradise Plus-A in the 8514/A category, and Desktop Computing, NEC, and Renaissance in the 34010 category.
To test these cards in the highest resolutions they were run using AutoCAD, OS/2 1.2, and Windows 3.0.

"Resolution: Supports 1,024 by 768 in 256 colors.
Speed: Although most benchmarks rival the other cards in the comparison, the AutoCAD redraw times were extremely slow.
Driver Support: Supports AutoCAD and a variety of other applications.
Setup: Installation is easy to follow.
Serviceability: External DIP switches makes for simple modification.
Support Policies: Trident has a two-year warranty.
Final Score: 6.0"

This final score put the TVGA in the middle of the Super VGA trio, with the Headland V-RAM VGA coming in at 7.1 due to Headland's 7-year warranty, good surface-mount components, excellent technical support, and most importantly, the best VGA performer. The Western Digital Paradise VGA 1024 came last in the Super VGA group with a score of 5.8. It could only handle 1024 x 768 in 16 colours, only had a 3-year warranty, setup instructions and other documentation were only satisfactory.
InfoWorld, July 1990

"PROS: Low cost, widest software support
CONS: Slow performance

The Trident Impact III costs only $12 more on the street than the rock-bottom Boca SuperVGA. Amazingly, for that low $172 price, you get the widest selection of drivers in the roundup.

Trident provides 132-column drivers for Word and WordStar, plus 256-color drivers in all super-VGA resolutions for both Windows and AutoCAD. You don't get a menu for swapping drivers, though, and hardware installation isn't switchless.

The board's speed could be better. In most of the key performance benchmarks, the Impact III hovered in the bottom third.

If you like the idea of 132-column word processing in Word, this board is your best choice. Otherwise, bargain hunters would do better to opt for the superior performance, switchless installation, and even lower price of the Boca SuperVGA."
PC World, August 1991

Setting it Up

The included software driver and utility disks that were provided with TVGA8900-based graphics cards usually came with these utilities from Trident (sometimes found in a directory called TVGAUTIL):

SVM89.EXE - Switch Video Mode
TVGABIO.SYS - can improve display speed by copying the VGA ROM BIOS into an area of system memory
TANSI.SYS - replaces standard DOS ANSI.SYS and supports extended text display modes
VESA.EXE - installs VESA BIOS extensions into memory
BIC.EXE - reports your PC's system BIOS information
MODETEST.EXE - checks your monitor's ability to run any display mode
MAMODE.EXE - selects 64 KB or 128 KB memory addressing scheme for high-res programs
PMFIX.EXE - for OS/2, circumvents display problem when using a standard VGA driver and switching between full-screen OS/2 and Presentation Manager.
RIXFIX.EXE - allows RIX programs to operate correctly
SMONITOR.EXE - use on monitors that don't conform to the monitor pinout standard and thus boot up in VGA monochrome
TVGACRTC.EXE - allows users to adjust video display specifically for their monitor. May also be used to select 70 Hz refresh rate for 1024x768 NI modes.

Trident cards that used the TVGA8900 series chipsets usually had a 6-switch DIP switch block accessible from the backplate. I don't have information on what these are specifically used for - they may be the same as for the TVGA8800 series.

In addition, some TVGA8900 cards have jumpers:

Jumper	Meaning	Configuration
J1	IRQ9 interrupt control	1-2 = Enabled 2-3 = Disabled
SW3	Select scan rate - allows you to configure scan rates of extended VGA modes to be compatible with a multiscan monitor. Works only with 512 KB / 1 MB configurations.	Open = 48.7 kHz scan rate (allows 1024 x 768 and higher to run in non-interlaced) Closed = Default scan rate
SW4	BIOS autodetect	Closed = disable autodetect Open = enable autodetect (BIOS will detect whether card is in 8-bit or 16-bit slot and configure accordingly)
J6	Monitor detection control. (use if your PC boots into monochrome VGA)	1-2* = Normal 2-3 = non-standard monochrome Unjumpered = non-standard colour