Retro
Hardware Examination: EG-3000 EGA Graphics Expansion Card
There are countless examples of
generic computer hardware from practically every era of personal
computing.
Here's one now. As usual, there is very little information to be found by
any popular search engine.
What you're looking at in the picture above is a particularly generic EGA
display adapter card. Apart from the EG-3000 text printed on the option
ROM IC, there's very little by which this adapter could be identified. An
easily overlooked clear plastic sticker on the back gives an FCC ID of E5Y-EG-3000A
(belonging to DFI Corporation and issued June 22nd, 1989). This card also
shows up with many other names on it, such as Octek. It really wouldn't be
all that interesting were it not for the very curious item at the top left
of the card. That's what drove me to write this page. How about a closer
look at that item?
As with many early video cards, this one
has no shortage of oscillators. Each one is responsible for the video
modes that the adapter can generate. On the main board itself, there are
24.000, 16.257, and 19.000 MHz oscillators. The curious daughtercard above
adds only one thing--a 34.0000 MHz oscillator. You might think that with
32 pins in that connector that perhaps the daughtercard provides more
video RAM, but no. Only three pins from that entire
connector are used to connect the oscillator with the other circuitry on
the card.
The board is marked only EG-3000 UPGRADE KIT.
I'm very curious as to what this "upgrade kit" makes possible. My guess is
that it adds an extra display mode or higher resolution to the card's
capabilities. Total Hardware '99 includes
this card in its library, but does not expand on exactly what purposes the
underlying "feature connector" has. Presumably other functionality is
offered, as approximately 11 pins are connected via traces on the board.
Although the board can be configured to output CGA video (or, supposedly,
monochrome video as well) the oscillators do not match the frequencies
needed for CGA or NTSC TV output. This would tend to suggest that the
video controller IC has a frequency synthesizer of its own onboard. You
can configure the video output characteristics with the onboard jumpers,
using the settings as explained by Total Hardware '99. I've not attempted
to verify how correct these are. They could be questionable, as the page
states the maximum video resolution of this adapter as a very implausible
800x600. The primary video output is via a 9 pin D shell female connector.
Two RCA jacks seemingly provide for composite video output. I find it a
bit surprising (and doubtful) that two of them are provided for this
purpose. Rounding out the user accessible connectors is a probable light
pen connection at P2 on the board. It's a little surprising to see this on
an EGA display adapter, as I don't recall seeing any others with this
feature. It was much more common on CGA display adapters.
Finally, there is the video processor IC itself. Unlike many no-name
adapters, the video processor has identifiable markings on it. It is
labeled as a Gemini VC-001, with copyright and mask rights markings dated
1987. This chip was made in Japan. I didn't find much online about it,
apart from a brief mention at a "VGA
Legacy" museum page. Gemini seemingly also designed a VGA controller
IC known as the VC-004.
"Gemini" seems to have been more completely known as "Gemini Technology
Incorporated". If it's the same company, a LinkedIn page belonging to an Edward
Dolejsi suggests that Gemini Technology was a Canadian firm that
designed PC emulators, various graphics chipsets, a cable free IBM PC
compatible and a laptop with (of all things) a built in telephone. I'd
like to contact Mr. Dolejsi to see if I could get more information or
confirm that the company he worked for is, or is not, the one I'm looking
for. Unfortunately, that does not seem to be possible without signing up
for LinkedIn, and I could not find any suitable e-mail address through a
web search.
(Editor's--and author's!--note: People have found my web pages in the most
unique ways, so I suppose it's not too much to hope that Mr. Dolejsi might
Google his name and see this page in the results.)
Other Stuff
In my efforts to find information concerning this adapter, I came
across some files said to contain both a ROM dump, as well as utilities
and drivers. Though I've not examined these in any great detail, the
utilities are fairly well documented and seem to suggest that many aspects
of the VC-001's operations can be changed by software while the computer
is running a DOS compatible operating system. Also provided with the
utilities is a tool to shadow the EGA BIOS in RAM, thus relieving some of
the performance penalty caused by directly accessing the ROM.
Drivers include the usual suspects, for programs such as AutoCAD. You'll
find a complete list of what drivers are provided by browsing the
downloaded drivers package, linked below.
Disclaimer (as always): I've not used
these files myself, or tested them in any way. They are provided ONLY as
a public service to owners of hardware based on the Gemini VC-001 video
processor IC. It's entirely possible that not all functions are
supported with all hardware variations and that attempting to use this
software could cause six foot flames (or worse) to shoot out of your
computer. You use these files ENTIRELY
AT YOUR OWN RISK. If you are not to prepared to assume all of the
responsibility for the results of using these files, do NOT download or
utilize them. Use of this software on other hardware may be a violation of
applicable laws and may in fact damage that hardware or anything attached
to it.
All of these files are in ZIP format and may be extracted using
functionality built into many operating systems, or by popular software
utilities such as WinZip or 7-Zip.
EG-3000 Expansion ROM v2.4 (the only version I've
seen, courtesy of VGA
Legacy Museum)
EG-3000 Drivers and Utilities
As always, I'm interested in any comments, questions or further
information you can provide. Contact me!
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Copyright © 2014 William R. Walsh. All Rights Reserved.
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