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O2 RGB mod


grips03

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Has anyone tried this O2 mod?

 

from:

http://videopac.nl

 

"

The RGB output circuit has been copied from the Videopac G7200 console.

It's the circuit that is enclosed in the red line in the schematic below.

The signals of this circuit with the numbered red dots should be connected to the corresponding numbered red dots in the schematic of the Odyssey2 console below. For dots 5 and 6 an inverter should be inserted before connecting them (74LS04).

 

http://ozyr.com/rene/Download/G7200_rgb.jpg
http://ozyr.com/rene/Download/odyssey2_schematic_rgb.jpg

"

 

 

If yes, can you help answer the questions below.

 

Between IC653 and IC652 there is a vertical black line. Is this to denote a header to G7200's CRT and hence is not needed for O2 RGB board?

Does IC653 pin 11 connect to IC652 pin 9 and pin 13?
Does IC653 pin 8 connect to IC652 pin 3

What does "&" mean inside of IC653?
What does "1" mean inside IC652?
I assume IC656 is not needed as its not in the red area, does that sound right?

 

I think these two are related to SCART pin 8/select and pin 16/blanking. Do you agree?
Are D698 and R749 needed? If it is needed where does one pick up +2v. Signal name is Status CVBS. Perhaps this is optional.
Is R723 needed, this appears to be a resistor connected to +5v, signal name is Status RGB. Perhaps this is optional.

 

IC652 is 7407

IC653 is 74LS08

IC656 is 74LS08

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Parts list:

 

R751 100 ohm

 

R774 180 ohm

 

R738 470 ohm

 

R736 560 ohm
R737 560 ohm
R735 560 ohm

 

R773 680 ohm

R747 1k5 aka 1.5K ohm
R746 1k5
R748 1k5

R733 4k7 aka 4.7K ohm
R772 4k7

 

C854 10nf aka 10000pf or .01uf .1 or 2.54mm spaced
C852 10nf

D696 1N4148 DO-35
D693 1N4148
D694 1N4148
D695 1N4148
D692 1N4148
D697 1N4148

 

74LS04 to invert points 5 and 6
IC652 7407 DIP14
IC653 74LS08 DIP14

TS681 BC548B TO-92

 

 

DIN - 8 pin female / panel mount SD-80LS (Digikey)

6 foot DIN 8 male cables assembly 10-00438 (Digikey)

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I haven't done the mod, but here's my thoughts:

 

The vertical black line is the 4 signals, shown as a bus, LGBR - similar as shown in the RAM above it.

Does IC653 pin 11 connect to IC652 pin 9 and pin 13? - Yes
Does IC653 pin 8 connect to IC652 pin 3 - Yes
What does "&" mean inside of IC653? - AND gate? If not, doesn't matter?
What does "1" mean inside IC652? - Buffer? If not, doesn't matter?
I assume IC656 is not needed as its not in the red area, does that sound right? - I think you'll need that if it's not already there.
I think these two are related to SCART pin 8/select and pin 16/blanking. Do you agree? - Probably agree = don't need.
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I haven't done the mod, but here's my thoughts:

 

The vertical black line is the 4 signals, shown as a bus, LGBR - similar as shown in the RAM above it.

Does IC653 pin 11 connect to IC652 pin 9 and pin 13? - Yes
Does IC653 pin 8 connect to IC652 pin 3 - Yes
What does "&" mean inside of IC653? - AND gate? If not, doesn't matter?
What does "1" mean inside IC652? - Buffer? If not, doesn't matter?
I assume IC656 is not needed as its not in the red area, does that sound right? - I think you'll need that if it's not already there.
I think these two are related to SCART pin 8/select and pin 16/blanking. Do you agree? - Probably agree = don't need.

 

 

For the first rev of the pcb I'm going to leave out the bus as I can't figure out why one would mix the RGB colors before sending to 7407 buffer.

 

Yes, you got it "&" for AND gate, then "1" Buffer, on OR gate they did "> = (vertically) 1" . Think this is the first time I saw that on a schematic. Kind of a cool little short hand.

 

I was able to confirm these signals are for SCART pin8 and PIN 16, so will leave off as I plan to use with XRGB and PVM.

post-27883-0-92949400-1482509061_thumb.png

post-27883-0-19409000-1482509084_thumb.jpg

post-27883-0-11736200-1482509090_thumb.jpg

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That vertical "bus" line is just a representation of all separate signals. It is not showing that they should be mixed together. I am not a fan of showing multiple signals as a single bus as it adds confusion. It confused me when I built this mod for my O2.

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That verrical "bus" line is just a representation of all separate signals. It is not showing that they should be mixed together. I am not a fan of showing multiple signals as a single bus as it adds confusion. It confused me when I built this mod for my O2.

 

edit: I found the diodes under the masking tape.

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Inputs to RGB PCB Going to use 2x5 / 10 pin IDC header

Sync - 612160 pin 8 or P8244 pin 5

Blank - 612160 pin 9

Red - 612160 pin 10 or P8244 pin 18

Video / [L]uma - 612160 pin 11

Blue - 612160 pin 12 or P8244 pin 20

Green - 612160 pin 13 or P8244 pin 19
Audio - P8244 pin 27

+5v = various spots

GND = various spots

 

612160 Color Encoder is labeled IC1 on O2 system board

P8244 is labeled IC5 on O2 system board

 

 

Outputs from RGB PCB Going to use 2x5 / 10 pin IDC header connected to DIN 8

Red - DIN pin 5

Green - DIN pin 8

Blue - DIN pin 3

Audio - DIN pin 7

Sync - DIN pin 4

GND - DIN pin 2

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  • 3 weeks later...

Updated pin names. Inputs to RGB PCB 2x5 / 10 pin IDC header

 

IDC Pin 1 / VCC = +5v

IDC Pin 2 / Composite Sync - 612160 pin 8 or P8244 pin 5

IDC Pin 3 / Blank - 612160 pin 9

IDC Pin 4 / Red - 612160 pin 10 or P8244 pin 18

IDC Pin 5 / Luma - 612160 pin 11 - currently labeled VID on rev 2 pcb

IDC Pin 6 / Blue - 612160 pin 12 or P8244 pin 20

IDC Pin 7 / Green - 612160 pin 13 or P8244 pin 19
IDC Pin 8 / Audio - P8244 pin 27

IDC Pin 9 / GND

IDC Pin 10 / GND

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  • 3 weeks later...

^^ 100% agree with CatPix. At the retro gaming expo I was arranging last weekend, we had several computers outputting RGB through a SCART cable where the RGB select signal was not enabled. Only a few of the CRT TV's we had brought had the option to manually select RGB mode, which meant some careful mixing and matching to get as many systems as possible running.

Edited by carlsson
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  • 2 weeks later...

Updated Parts list to buy from Digikey, Mouser, etc.

All resistors are 1/4watt axial 1%.

 

R723 47 ohm (not usually needed, RGB status only)

R751 100 ohm

R774 180 ohm

R738 470 ohm

Qty 3 R735, R736, R737 560 ohm

R773 680 ohm

Qty 3 R746 (labeled R745 on pcb), R747, R748 1k5 aka 1.5K ohm

Qty 2 R772, R733 4k7 aka 4.7K ohm

Qty 2 C852, C854 10nf aka 10000pf or .01uf .1 or 2.54mm spaced

Qty 6 D692-D697 1N4148 DO-35

74LS04 (to invert points 5 and 6) - labeled IC3 on the RGB PCB.
IC652 7407 DIP14
IC653 74LS08 DIP14

TS681 BC548B TO-92

DIN - 8 pin female / panel mount SD-80LS (Digikey)
6 foot DIN 8 male cables assembly 10-00438 (Digikey)

Qty 1 H3CCS-1036M (Digikey) <-- this is 10 position ribbon cable with connector on it
Qty 2 302-S101 (Digikey) <--this is 4 wall shrouded header that accepts the cable above
Qty 1 SCART plug 21 pin male connector (Console5.com)

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Inputs to RGB PCB 2x5 / 10 pin IDC header (updated 2/26/2017)

 

Best to use IC1/612160 for the inputs, except for audio.

 

IDC Pin 1 / VCC +5v / 612160 Pin 1

IDC Pin 2 / Composite Sync - 612160 pin 8 or P8244 pin 5

IDC Pin 3 / Blank - 612160 pin 9

IDC Pin 4 / Red - 612160 pin 10 or P8244 pin 18

IDC Pin 5 / Luma - 612160 pin 11 - Labeled VID on rev 2 and LUM on rev 2a pcb

IDC Pin 6 / Blue - 612160 pin 12 or P8244 pin 20

IDC Pin 7 / Green - 612160 pin 13 or P8244 pin 19
IDC Pin 8 / Audio - P8244 pin 27

IDC Pin 9 / GND / 612160 Pin 15 or 16

IDC Pin 10 / GND - Normally not connected (spare)

 

Outputs from RGB PCB towards DIN 8 connector.
IDC Pin 1 = RED
IDC pin 2 = GRN / Green
IDC Pin 3 = BLU / Blue
IDC Pin 4 = SC / Composite Sync
IDC Pin 5 = AUD / Audio
IDC Pin 6 = SR / Status RGB - not used for XRGB
IDC Pin 7 = NC
IDC Pin 8 = NC
IDC Pin 9 = NC
IDC Pin 10 = GND

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