Graphics boards

PCs had to display text and graphics some way. First, a MDA board was used known as Monochrome Display Adapter. MDA could only display text, using font from ROM memory located on board. For graphics, a CGA (Colour Graphics Adapter) board had to be used which could display in 4 colours (of 8) and in a bit higher resolution in monochrome.
The problem with MDA was its fixed font, while CGA had poor resolution. As solution, a Hercules graphics card (HGC) was developed. Hercules allowed to put text using on-ROM font in MDA-like mode, or use the same mode for graphics, giving 720x348 resolution for monochrome graphics. This way, if e.g. foreign characters had to be displayed and they were not present in ROM, it was even possible to "patch" the text mode by the cost of processing speed.
Both IBM and other companies released other adapters to add support for better, faster and more colorful video. A PGC - Professional Graphics Controller - was in fact a computer on a board giving 640x480 resolution in 256 colours of a 2048-colour pallette. IBM's next move was EGA (Enhanced Graphics Adapter) could reach 640x350 with 16 colours.
Then, capabilities of TTL displays at IBM ended. Later 8514 and VGA boards used analog monitors. VGA - Video Graphics Array  (this time Array - a chip, not a whole board), could get 640x480 in 16 colours as well as 320x200 at 256. Later expansions in video memory and chipset access times allowed to have better resolutions like 800x600 at 256 colours (SVGA - Super VGA).
For along time even in 1990s there was an opinion that for an office computer it's not needed to use VGA - Hercules was totally OK. With Windows 3.x getting popular VGA gained its popularity and in mid-1990s a typical PC clone contained a 16-bit ISA VGA board, usually with Trident chipset. 256kB or 512kB of video RAM was totally enough, giving 800x600 at 256 colours what was totally OK when operating in Windows 3.x. Nevertheless, most middle-end monitors could not operate with better resolutions (or 1024x768 in interlaced mode).

For information about boards, I recommend to visit a VGA Museum website, they have a large collection.

For Taiwanese PC clones, MDA was rarely used. Here we have a Hercules board with built-in ROM, made around discrete chips with only small share of VLSI circuits. As usual, it has parallel port for printer, being a Video and printer adapter. The board is quite large and fills a whole standard of full-height full-length board.

Yamaha V6363 was an MDA/CGA/HGC chip which was frequently used in late 80s. This board has also a printer adapter and light pen connector, as with CGA, which was rarely used. There is also a jumper to select colour or monochrome (MDA/HGC) modes because some displays shown CGA modes badly.
The ROM contains character data for typical US American codepage 437, it means that this board was not modified. Or it comes from import after it was used.
In Poland, most boards imported had modified ROM to Polish character set.
Another clone of Hercules using single chip was TD3088, used in many boards in late 80s. Contrary to earlier boards this one has jumpers to set position of parallel interface (LPT1, LPT2) or disable it at all, I don't know what JP1 is for. As most similar boards used 8 4164 chips, this one uses two 4464, so the same amount of memory is in 2 chips.
This board has modified character ROM, adding local characters.
As you can see, a whole Hercules circuitry of full-ength ISA board could be squeezed into one dedicated chip in a few years.

Protons and Winbonds were the most popular Hercules clones, being used in PC clones even in 1990s. They were imported and sold with or without local character ROM. Similar boards have been made since mid-1980s even in 1992. More high-end models had jumpers for disabling and setting printer port, while cheaper ones had it hard-wired.

     

MCGVP MCG2502 was a CGA-compatible board also used in PC clones. It has localized character ROM and printer port, some versions have a TV-OUT connector used in CGA modes. What's more interesting, according to VGA Legacy this chipset was used in imported Mazovia computers.
This board is made the way that it can use both 4164 as well as two 4464 chips for video memory.
ATI Small Wonder Graphics Solution was one of the first ATI video boards, made in early 1990s. It was compatible with CGA, and in CGA modes it was possible to display on a TV using composite output. 64kB of RAM has been soldered in mainboard.
This particular board has a German character ROM.

  TH99
Genoa EGA clone with 256kB of RAM. In 1990s there were lots of EGA and VGA clones with more-or-less similar compatibility. This one is EGA, with two (?) composite outputs as well as light pen connector.
I don't know about this one, but Genoa was known in VGA world that they included some undocumented modes here and there, and some software included workarounds and drivers to make them available.

  TH99 (the closest one)
Octek EVGA-8 was an early-1990s VGA and EGA-compatible board. VGA display can be connected.

  BIOS Dump
Paradise VGA - a very popular VGA clone in early 1990s. This board was the easiest and cheapest way to get 800x600 with 16 colours in 1990 and 1991. This board had some advanced features - it has standard VGA feature connector (standard in early 1990s was an edge connector).
The WD Paradise chipsets were quite popular and we will meet them again in some later boards.

  TH99 (the closest one)
  BIOS
For 16-bit systems there was also a 16-bit version of Paradise VGA board. And also it was one of the cheapest way to get 800x600.
  TH99 (the closest one)
  BIOS

An earlier unit was WD90C00, with similar capabilities and BIOS.
Realtek RTVGA9007 was the higher-end VGA board in early 1990s. It was possible to connect VGA display as well as TTL one which emulated color. its 512kB of RAM allowed to get even a nice 1024x768 when good monitor was used.

Simultaneously, Oak Technology released their own VGA boards with their chips. Here we have two boards, from 1991 and 1992, with typical (800x600) VGA capabilities.


OTI37c board with 256kB of VRAM
  BIOS Dump


OTI077 board with 1MB of VRAM, 1993
   BIOS Dump

 

All-time popular boards, Trident TVGAs. Their popularity started around 1992 or 93, and they were used even in 96 in low-end systems. There were lots of boards containing TVGA chips, with 256, 512 or 1024kB of video RAM. Many of these boards had a segment of 3 jumpers which allowed to run them in 8-bit slot.
A typical problem with these boards was the dependency on BIOS video settings - if something was wrong there, it rendered the picture in grayscale. Many Trident boards also used a monitor detection quite incompatible with modern TTL signals on detection lines, and its fault also resulted in grayscale picture.


TVGA8900 with 1MB of VRAM
  BIOS Dump
TVGA9000i with 256kB of VRAM, the most popular one
  BIOS dump
TVGA9000C with 512kB of VRAM
  BIOS dump
Similar TVGA900C, also 512kB
  BIOS Dump

 

Cirrus Logic was competing with Trident these times. They also made similar boards, and their VGA boards were popular too. There was an opinion that some Cirrus boards are a bit faster than Tridents when it comes to re-drawing a complete screen in higher resolutions like 800x600.


CL-GD5401 with 256kB of VRAM
CL-GD5402 with 512kB.
  Dump
I have no idea what this thing is. The chipset was made by HMC, it has 512kB of VRAM and requires parity for it. It was made around 1994 and probably is not very fast.

   BIOS dump

Most of ISA chipsets were improved and used in VLB (VESA Local bus) boards too. VLB slots lived shortly in 486 computers, mostly because of forcing synchronization with CPU clock. Also, technical difficulties arose when adding one more slot to 16-bit ISA. Here we can see two boards, one is a typical video-only board, the second is a "combo" board - it has a video board, serial and parallel port controller as well as IDE and FDD controllers in a single board.


Cirrus CL-GD5424 with 512kB of VRAM
  Dump
Octek Combo board with Cirrus CL-GD5426, 256kB of VRAM.

Now let's look at some PCI boards. The most popular ones were S3 Trio64 and later, a bit better ViRGE. The ViRGE had some small 3D acceleration totally sufficient for games. Most of these boards had 1 or 2MB of video memory allowing to get better resolutions and colour depths up to 24-bit. Notice the "VIRGE TRIO" board in which they had no ide what chip will be.

Here are ViRGEs:

And here are Trios:

However, office computers used cheaper boards. Typical examples were Alliance ProMotion or SiS 6202. The SiS chipset became popular as a chipset allowing to just show things on screen - some mainboards even had it built-in.

When higher resolution, quality or speed was needed, as well for upgrading systems in which AGP was not available, a better boards could be later purchased - like this Matrox:

These boards were faster and had larger memory.

Multimedia expansions

There were things which video boards could not do. Decoding a video for DVD could be done with CPU, but it required a very fast processor these times. To solve this problem, boards like this one were used - they added a complede dedicated MPEG decoder chip to a computer. It communicated with PC using video overlay (adding picture right to the signal fed to monitor) or just emitted picture on TV out. They required specific drivers and software.
Generally the picture quality of dedicated decoders was better than CPU decoders. These boards became obsolete when CPUs became powerful enough to encode and decode video in a real time.

 

Since 1990s there were boards allowing to watch TV on computer's monitor. In he most simple form it was just a computer-controlled tuner which substituted monitor image with TV image. Later, more complex boards could even record some video./
Below, 3 boards are present. A TV Magic ISA board, a quite early TV tuner with only watching capability. In the middle we have AverTV, which fed the picture data to the computer, and the last one is a newer Pinnacle tuner with digital TV decoder capability.