I.WANT.V.G.A. lol

Hardware questions and modifications

I.WANT.V.G.A. lol

Postby MikeModified » Wed Mar 18, 2015 5:01 pm

After all, I have VGA for my TRS-80 Model I courtesy of the Mise and VGA on my Apple IIGs by using a GBS-8220* to convert the Gs's 16kHz signal to VGA.

After reading in this thread - http://www.vintage-computer.com/vcforum/showthread.php?40965-Commodore-128-Video-DAC-Board-Available - that the DAC board would work, in conjunction with the GBS-8220, with PC CGA, I ordered one from http://he-insanity.blogspot.com/2014/03/commodore-128-cga-video-dac-board.html

It works! On my $20 thrift store HP flatscreen @1024x768, the colors are good (my camera washes out the lighter colors):

Image

Image

Image

The characters are crisp, much more readable than the standard jr monitor, although some pixels are grey instead of white:

Image

Additional items needed:

1) Adapter cable for IBM color display
2) DB-9 M/F extension cable (I got a 6' cable cheaply at a Tandy store close-out)
3) A 5VDC power supply, 5mm-2mm
4) 1 6-pin Molex connector (Digi-key numbers on the DAC website) to adapt the GBS-8220 cable to the DAC adapter
5) 2 2-pin Molex connectors (Digi-key numbers on the DAC website) to power the DAC from the 8220

Mike

*Manual: http://www.jammaboards.com/arcade_manuals/GBS-8220_CGA_to_VGA_HD-Converter.pdf
eBay source: http://www.ebay.com/itm/261153377967?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
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Re: I.WANT.V.G.A. lol

Postby Sharkey1331 » Wed Mar 18, 2015 7:25 pm

Looks real cool!!! I never knew about this project- thank you!!! :-)

Can you post another picture, showing the 80 column text, zoomed out a bit so I can see the overall quality/readability?

Thanks!!
Jason
IBM PC Jr. NEWB! Parallel sidecar, Hotshot II (soon to be replaced with JRide)

Also, check out my clone of the Altair 8800micro Clone:
https://www.youtube.com/watch?v=y19zdzP ... yX5JoOO4qA
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Re: I.WANT.V.G.A. lol

Postby MikeModified » Wed Mar 18, 2015 8:22 pm

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Re: I.WANT.V.G.A. lol

Postby James » Thu Mar 19, 2015 8:27 am

What is the 6' DB9 cable for? I must be missing something, The PCjr to CGA cable plugs into the DAC. The DAC uses the 6 wire molex to send signal to the GBS-8220 (and two wire molex for power). The VGA cable plugs into the GBS-8220. What am I missing.?

Does the DAC come with any instructions?
-PCjr (1989)-DOS 3.3, Racore Drive II, jrIDE-128 MB DOM, jrExcellerator, Tandy Mod, Serial Card, Combo v2, Config Plus, IBM Parallel Port, Megaboard, Xircom PE3-10BT
-PCjr (2001)-DOS 3.3, jrIDE-128 MB DOM, NEC v20, Parallel Port, Comswap, Xircom PE3-10BT
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Re: I.WANT.V.G.A. lol

Postby MikeModified » Thu Mar 19, 2015 8:45 am

Correct. It's not needed, but it greatly helps to ease the congestion immediately behind the jr.

Mike
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Re: I.WANT.V.G.A. lol

Postby James » Thu Mar 19, 2015 9:09 am

I took a look at the PCjr to CGA monitor adapter and it is a stubby little thing. It's probably a good idea to add an extension cable just to protect the pins and plastic separators.
-PCjr (1989)-DOS 3.3, Racore Drive II, jrIDE-128 MB DOM, jrExcellerator, Tandy Mod, Serial Card, Combo v2, Config Plus, IBM Parallel Port, Megaboard, Xircom PE3-10BT
-PCjr (2001)-DOS 3.3, jrIDE-128 MB DOM, NEC v20, Parallel Port, Comswap, Xircom PE3-10BT
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Re: I.WANT.V.G.A. lol

Postby MikeModified » Thu Mar 19, 2015 9:14 am

Exactly! ;)

Mike
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Re: I.WANT.V.G.A. lol

Postby James » Fri Mar 20, 2015 7:01 am

Good find. One of my PCjr monitors is being to hum. Maybe nothing, maybe a sign of impending death. Could be the way to go

I too have a few of those thrift store 1024 x 768 14" LCD monitors. How do you pass up flawless monitors for $12.99
-PCjr (1989)-DOS 3.3, Racore Drive II, jrIDE-128 MB DOM, jrExcellerator, Tandy Mod, Serial Card, Combo v2, Config Plus, IBM Parallel Port, Megaboard, Xircom PE3-10BT
-PCjr (2001)-DOS 3.3, jrIDE-128 MB DOM, NEC v20, Parallel Port, Comswap, Xircom PE3-10BT
James
 
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Re: I.WANT.V.G.A. lol

Postby OldComputerGuy » Fri Aug 04, 2017 3:03 pm

Are games actually playable with this monitor on a Jr? I would think they would be a slideshow.
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Re: I.WANT.V.G.A. lol

Postby James » Fri Aug 04, 2017 11:26 pm

The PCjr puts out a CGA signal. The processing of the upscaling and conversion takes place in the d/a converter and cga to vga converter
-PCjr (1989)-DOS 3.3, Racore Drive II, jrIDE-128 MB DOM, jrExcellerator, Tandy Mod, Serial Card, Combo v2, Config Plus, IBM Parallel Port, Megaboard, Xircom PE3-10BT
-PCjr (2001)-DOS 3.3, jrIDE-128 MB DOM, NEC v20, Parallel Port, Comswap, Xircom PE3-10BT
James
 
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