kiyotewolf
Experienced Member
Got a CGA card off ebay, and it's only displaying B/W composite graphics on the TV.
[IN 16 COLOR COMPOSITE MODE -- TO A TV]
There are two RCA jacks, one with what appears to be B/W video on purpose, and the other, supposedly a color video jack.
Do you have to set a border color or something, to make the color composite mode stick?
I'm using my TSR which twiddles the color burst flag in the 3D8h port, which enables the color burst mode in DOSBOX, but, with my board, it splits the video into four copies of the same image, and much darker.
Maybe my board has a bug somewhere on it?
~Paul
Here's the code I use to make the CGA color burst flag activate..
DEF SEG = 0
a = PEEK(&H410)
POKE &H410, (a AND &HCF) OR &H20
OUT &H3D8, INP(&H3D8) AND 251
DEF SEG
[update]
The Wikipedia article said that a misaligned trimpot for the color might make it not product any color at all.
Looked, no trim pot.
It's a Rev 4 board, the long very old style ones.
Also, there's a jumper, marked "E1" at the end of the board, and the two header connectors near the front for the light pen, and other [i forget?] connections.
[update 2]
http://stason.org/TULARC/pc/graphics-cards/U-Z/UNIDENTIFIED-CGA-Monochrome-CGA-PC-T.html
This is a schematic shaped diagram of what my card looks like.
[update 3]
I think that little E1 jumper enabled the alternate font, I jumpered it. Did not blow up.
I also used Trixter's Tweakmode CGA test program, VGA2CGA.EXE, and it came up black and white.
Maybe this is truely a monochrome card and I'm out of luck.
[update 4]
http://www.ebay.com/itm/IBM-5170-Co...deo_TV_Cards&hash=item45ffb83459#ht_500wt_949
http://www.ebay.com/itm/IBM-6133807...eo_TV_Cards&hash=item2ebb5a4788#ht_4330wt_932
I'm looking at these two cards on ebay, and I can't seem to see a little trimpot on the boards, which worries me.
I don't wanna shell out more money, if these aren't color CGA cards. [color in composite mode]
[IN 16 COLOR COMPOSITE MODE -- TO A TV]
There are two RCA jacks, one with what appears to be B/W video on purpose, and the other, supposedly a color video jack.
Do you have to set a border color or something, to make the color composite mode stick?
I'm using my TSR which twiddles the color burst flag in the 3D8h port, which enables the color burst mode in DOSBOX, but, with my board, it splits the video into four copies of the same image, and much darker.
Maybe my board has a bug somewhere on it?
~Paul
Here's the code I use to make the CGA color burst flag activate..
DEF SEG = 0
a = PEEK(&H410)
POKE &H410, (a AND &HCF) OR &H20
OUT &H3D8, INP(&H3D8) AND 251
DEF SEG
[update]
The Wikipedia article said that a misaligned trimpot for the color might make it not product any color at all.
Looked, no trim pot.
It's a Rev 4 board, the long very old style ones.
Also, there's a jumper, marked "E1" at the end of the board, and the two header connectors near the front for the light pen, and other [i forget?] connections.
[update 2]
http://stason.org/TULARC/pc/graphics-cards/U-Z/UNIDENTIFIED-CGA-Monochrome-CGA-PC-T.html
This is a schematic shaped diagram of what my card looks like.
[update 3]
I think that little E1 jumper enabled the alternate font, I jumpered it. Did not blow up.
I also used Trixter's Tweakmode CGA test program, VGA2CGA.EXE, and it came up black and white.
Maybe this is truely a monochrome card and I'm out of luck.
[update 4]
http://www.ebay.com/itm/IBM-5170-Co...deo_TV_Cards&hash=item45ffb83459#ht_500wt_949
http://www.ebay.com/itm/IBM-6133807...eo_TV_Cards&hash=item2ebb5a4788#ht_4330wt_932
I'm looking at these two cards on ebay, and I can't seem to see a little trimpot on the boards, which worries me.
I don't wanna shell out more money, if these aren't color CGA cards. [color in composite mode]
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