Cables - IanSB/RGBtoHDMI GitHub Wiki

NOTE: Always ensure that cables are connected before powering on your system and the converter and never plug or unplug cables with the power on.

16 way (12 bit extender) or 12 way (RGBtoHDMI main board) IDC header to TTL computer connections

Note: 3 bit RGB TTL computers like the BBC micro, Oric/Atmos, QL or Camputers Lynx can also be connected via the 6 way IDC on the analog board or 3 bit TTL buffer board. (See below)
For connections using the 10 way header on the old 6 bit design visit here: old 6 bit connections

BBC micro / Master 128 / Electron (3 bit RGB TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 6 way DIN Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Pin 5
Pin 8 green2 Pin 4 green2
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3 Pin 1
Pin 12 HSYNC Pin 8 HSYNC Pin 4
Pin 13 GREEN3 Pin 9 GREEN3 Pin 2
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 Pin 3
Pin 16 +5V Pin 12 +5V Pin 6 Leave unconnected if powering Pi externally

Spectrum 128 or +2 (grey) and QL (4 bit RGBI TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 8 way DIN Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Pin 2
Pin 8 green2 Pin 4 green2 Pin 3 Intensity
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3 Pin 7
Pin 12 HSYNC Pin 8 HSYNC Pin 4
Pin 13 GREEN3 Pin 9 GREEN3 Pin 6
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 Pin 8
Pin 16 +5V Pin 12 +5V

Note the green2 / intensity pin is not used on the QL as it is only 3 bit TTL but the same cable can be used

Oric 1 / Atmos (3 bit RGB TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 5 way 180° DIN Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Pin 5
Pin 8 green2 Pin 4 green2
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3 Pin 1
Pin 12 HSYNC Pin 8 HSYNC Pin 4
Pin 13 GREEN3 Pin 9 GREEN3 Pin 2
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 Pin 3
Pin 16 +5V Pin 12 +5V

Camputers Lynx (3 bit RGB TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 5 way 240° DIN Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Shield Must be connected to both shield halves
Pin 8 green2 Pin 4 green2
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3 Pin 5
Pin 12 HSYNC Pin 8 HSYNC Pin 1
Pin 13 GREEN3 Pin 9 GREEN3 Pin 4
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 Pin 2
Pin 16 +5V Pin 12 +5V

Note the 5 way 240° DIN has different pin numbering to the 5 way 180° DIN

Sharp MZ700 (3 bit RGB TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 8 way DIN Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Pin 2
Pin 8 green2 Pin 4 green2
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3 Pin 6
Pin 12 HSYNC Pin 8 HSYNC Pin 3 CSYNC
Pin 13 GREEN3 Pin 9 GREEN3 Pin 7
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 Pin 8
Pin 16 +5V Pin 12 +5V

Intellivision (4 bit TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC AY-3-8900 chip Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND AY-3-8900 Pin 1 Vss on AY-3-8900
Pin 8 green2 Pin 4 green2 AY-3-8900 Pin 16 V4 on AY-3-8900
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3 AY-3-8900 Pin 22 V1 on AY-3-8900
Pin 12 HSYNC Pin 8 HSYNC AY-3-8900 Pin 19 V5 on AY-3-8900
Pin 13 GREEN3 Pin 9 GREEN3 AY-3-8900 Pin 21 V2 on AY-3-8900
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 AY-3-8900 Pin 18 V3 on AY-3-8900
Pin 16 +5V Pin 12 +5V

IBM PC MDA, CGA, EGA (2, 4 or 6 bit TTL) / Olivetti Prodest PC1 (4 bit RGBI TTL) / Commodore 128 80 column (4 bit RGBI TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 9 way D-Type Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Pin 1
Pin 8 green2 Pin 4 green2 Pin 6 Intensity in CGA / MDA
Pin 9 red2 Pin 5 red2 Pin 2
Pin 10 blue2 Pin 6 blue2 Pin 7
Pin 11 RED3 Pin 7 RED3 Pin 3
Pin 12 HSYNC Pin 8 HSYNC Pin 8
Pin 13 GREEN3 Pin 9 GREEN3 Pin 4 Video in MDA
Pin 14 VSYNC Pin 10 VSYNC Pin 9
Pin 15 BLUE3 Pin 11 BLUE3 Pin 5
Pin 16 +5V Pin 12 +5V N/C

Note: You can use a straight through IDC ribbon to a 9 way IDC D type connector connected to ribbon from GND to BLUE3

Sam Coupe (7 bit RrGgBbI TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC Euroconnector Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1 31A BRIGHT
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND 32C 0 VOLTS
Pin 8 green2 Pin 4 green2 31C GREEN0
Pin 9 red2 Pin 5 red2 30A RED0
Pin 10 blue2 Pin 6 blue2 29A BLUE0
Pin 11 RED3 Pin 7 RED3 25A RED1
Pin 12 HSYNC Pin 8 HSYNC 27A CSYNC
Pin 13 GREEN3 Pin 9 GREEN3 26A GREEN1
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3 26C BLUE1
Pin 16 +5V Pin 12 +5V 32A +5V

(Elan) Enterprise (8 bit RrrGggBb TTL)

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC Internal IC Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1 IC33 Pin 5
Pin 6 blue1 Pin 2 blue 1 IC33 Pin 14 same as blue3
Pin 7 GND Pin 3 GND IC33 Pin 10 0 VOLTS
Pin 8 green2 Pin 4 green2 IC33 Pin 9
Pin 9 red2 Pin 5 red2 IC33 Pin 12
Pin 10 blue2 Pin 6 blue2 IC33 Pin 7
Pin 11 RED3 Pin 7 RED3 IC33 Pin 18
Pin 12 HSYNC Pin 8 HSYNC >IC32 Pin 8< CSYNC on different chip
Pin 13 GREEN3 Pin 9 GREEN3 IC33 Pin 16
Pin 14 VSYNC Pin 10 VSYNC IC33 Pin 3 GREEN1 in 9bpp (Vsync) mode
Pin 15 BLUE3 Pin 11 BLUE3 IC33 Pin 14 same as blue1
Pin 16 +5V Pin 12 +5V IC33 Pin 20 +5V

Apple IIc digital interface (1 + 1 bit TTL)

This is preferred to connecting using the analog composite video interface as the 4 lines of text in mixed text and graphics mode will be displayed without artifacts.

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC 15 way D-Type Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND Pin 13 GND
Pin 8 green2 Pin 4 green2 Pin 10 GR - switches graphics on
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3
Pin 12 HSYNC Pin 8 HSYNC Pin 3 SYNC - Composite sync
Pin 13 GREEN3 Pin 9 GREEN3 Pin 11 SEROUT - TTL inverted video
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3
Pin 16 +5V Pin 12 +5V N/C

Apple IIe digital interface internal pickup (1 + 1 bit TTL)

This is preferred to connecting using the analog composite video interface as the 4 lines of text in mixed text and graphics mode will be displayed without artifacts.

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC Motherboard Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND UF5 166 pin 8 74166 GND
Pin 8 green2 Pin 4 green2 UE5 344-002x pin 2 IOU GR - switches graphics on
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3
Pin 12 HSYNC Pin 8 HSYNC UE5 344-002x pin 39 IOU SYNC - Composite sync
Pin 13 GREEN3 Pin 9 GREEN3 UF5 166 pin 1 or pin 13 74166 SEROUT - TTL inverted video
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3
Pin 16 +5V Pin 12 +5V UF5 166 pin 16 74166 +5V leave unconnected if powering Pi externally

Apple II / II+ digital interface internal pickup (1 + 1 bit TTL)

This is preferred to connecting using the analog composite video interface as the 4 lines of text in mixed text and graphics mode will be displayed without artifacts.

12 Bit Extender 16 way IDC RGBtoHDMI 12 way IDC Motherboard Notes
Pin 1 green0
Pin 2 red0
Pin 3 blue0
Pin 4 green1
Pin 5 red1 Pin 1 red1
Pin 6 blue1 Pin 2 blue 1
Pin 7 GND Pin 3 GND chip B10 pin 7 GND
Pin 8 green2 Pin 4 green2 chip B13 pin 13 switches graphics on
Pin 9 red2 Pin 5 red2
Pin 10 blue2 Pin 6 blue2
Pin 11 RED3 Pin 7 RED3
Pin 12 HSYNC Pin 8 HSYNC chip C13 Pin 8 Composite sync
Pin 13 GREEN3 Pin 9 GREEN3 chip B10 pin 5 Video output
Pin 14 VSYNC Pin 10 VSYNC
Pin 15 BLUE3 Pin 11 BLUE3
Pin 16 +5V Pin 12 +5V Chip B10 pin 14 +5V leave unconnected if powering Pi externally

Apple IIGS (12 bit RGB TTL)

12 Bit Extender 16 way IDC Motherboard Notes
Pin 1 green0 H3 Pin 5
Pin 2 red0 H4 Pin 5
Pin 3 blue0 H2 Pin 5
Pin 4 green1 H3 Pin 4
Pin 5 red1 H4 Pin 4
Pin 6 blue1 H2 Pin 4
Pin 7 GND H3 Pin 7
Pin 8 green2 H3 Pin 3
Pin 9 red2 H4 Pin 3
Pin 10 blue2 H2 Pin 3
Pin 11 RED3 H4 Pin 2
Pin 12 HSYNC H1 Pin 3
Pin 13 GREEN3 H3 Pin 2
Pin 14 VSYNC UF3 Pin 2 (74F86) Flip 6 Also available on VGC Pin 49 and TP24
Pin 15 BLUE3 H2 Pin 2
Pin 16 +5V H1 Pin 10 Leave unconnected if powering Pi externally

Atari ST 40 pin shifter (9 bit RGB TTL + mono TTL)

12 Bit Extender 16 way IDC Motherboard Notes
Pin 1 green0 Shifter40 pin 26 G0
Pin 2 red0 Shifter40 pin 29 R0
Pin 3 blue0 Shifter40 pin 23 B0
Pin 4 green1 Shifter40 pin 25 G1
Pin 5 red1 Shifter40 pin 28 R1
Pin 6 blue1 Shifter40 pin 22 B1
Pin 7 GND Shifter40 pin 20
Pin 8 green2 Shifter40 pin 24 G2
Pin 9 red2 Shifter40 pin 27 R2
Pin 10 blue2 Shifter40 pin 21 B2
Pin 11 RED3 N/C
Pin 12 HSYNC Glue pin 37 Also on modulator connector pin 5
Pin 13 GREEN3 Shifter40 pin 30 MONO
Pin 14 VSYNC Glue pin 38 Also on modulator connector pin 4
Pin 15 BLUE3 Glue pin 36 BLANK Also on diodes near shifter
Pin 16 +5V Shifter40 Pin 40 Leave unconnected if powering Pi externally

Photos showing connections on an Atari STFM using the 40 pin ST shifter pickup board. Other ST models may require different pickup points for the Hsync, Vsync and Blank signals:
images/cables/ataristfm1.jpg
images/cables/ataristfm2.jpg
This photo shows the optional use of a cable mounted header so the external cable can be detached rather than having a permanently attached captive cable:
images/cables/ataristfm3.jpg

Atari STE 84 pin shifter (12 bit RGB TTL + mono TTL)

There is a problem with bit ordering due to the way that the STE schematic numbered the bits.

On RGBtoHDMI the bits are R3, R2, R1, R0 ; G3, G2, G1, G0 ; B3, B2, B1, B0 with the '3' being the most significant bit and '0' being the least significant bit.

On the ST there were only 3 bits each of RGB and they were numbered R2, R1, R0 and they could be mapped easily to the existing RGB inputs with the same order.

However on the STE an extra bit for each of RGB was added and this was the least significant bit but it was named R3, G3, B3 so the bit ordering is messed up. This may have been done so that the most significant 3 bits matched the ST but it meant that the bit order was R2, R1, R0, R3 etc. which means that the Rx Gx Bx bits cannot be mapped directly.

The correct order is RGBtoHDMI R3, R2, R1, R0 to STE R2, R1, R0, R3 etc:

12 Bit Extender 16 way IDC Motherboard Notes
Pin 1 green0 Shifter84 pin 42 shifter G3
Pin 2 red0 Shifter84 pin 38 shifter R3
Pin 3 blue0 Shifter84 pin 46 shifter B3
Pin 4 green1 Shifter84 pin 45 shifter G0
Pin 5 red1 Shifter84 pin 41 shifter R0
Pin 6 blue1 Shifter84 pin 49 shifter B0
Pin 7 GND Shifter84 pin 74 or 75
Pin 8 green2 Shifter84 pin 44 shifter G1
Pin 9 red2 Shifter84 pin 40 shifter R1
Pin 10 blue2 Shifter84 pin 48 shifter B1
Pin 11 RED3 Shifter84 pin 39 shifter R2
Pin 12 HSYNC U211C pin 6 (74LS04) Composite sync: Also on U403 (MC1377) Pin 2
Pin 13 GREEN3 Shifter84 pin 43 shifter G2
Pin 14 VSYNC Shifter84 pin 50 MONO
Pin 15 BLUE3 Shifter84 pin 47 shifter B2
Pin 16 +5V Shifter84 Pin 11 or 32 Leave unconnected if powering Pi externally

It is probably easier to solder the RGB lines to the ends of the resistors connected to the shifter so the easiest way to avoid confusion is to go by resistor values:

The smallest value RGB resistors (1.5K) are connected to RGBtoHDMI R3, G3, B3
The next largest value RGB resistors (3K) are connected to RGBtoHDMI R2, G2, B2
The next largest value RGB resistors (6.2K) are connected to RGBtoHDMI R1, G1, B1
The largest RGB resistor values (12k) are connected to RGBtoHDMI R0, G0, B0

Use an STE diagnostic cartridge or program to display RGB colour gradients which should show if the connections are correct

6 way IDC (Analog interface or 3 bit TTL buffer) to computer connections

Note: The TTL computers will also work with the analog interface

BBC micro / Master 128 / Electron (3 bit RGB TTL)

RGBtoHDMI 6 way IDC 6 way DIN Notes
Pin 1 GND Pin 5
Pin 2 SYNC Pin 4
Pin 3 BLUE Pin 3
Pin 4 GREEN Pin 2
Pin 5 RED Pin 1
Pin 6 +5V Pin 6 Leave unconnected if powering Pi externally

Amstrad CPC (Analog RGB - same as BBC except power)

RGBtoHDMI 6 way IDC 6 way DIN Notes
Pin 1 GND Pin 5
Pin 2 SYNC Pin 4
Pin 3 BLUE Pin 3
Pin 4 GREEN Pin 2
Pin 5 RED Pin 1
Pin 6 +5V N/C

Spectrum +2 (grey), +2A, +3 and Sinclair QL (Analog RGB)

RGBtoHDMI 6 way IDC 8 way DIN Notes
Pin 1 GND Pin 2
Pin 2 SYNC Pin 4
Pin 3 BLUE Pin 8
Pin 4 GREEN Pin 6
Pin 5 RED Pin 7
Pin 6 +5V N/C

Spectrum 128 can be used with the analog board by connecting three 1N4148 diodes from the intensity DIN pin 3 to each of the RGB pins (DIN pins 6,7,8) with banded ends of the diodes towards to pin 3 of the 8 way DIN)

Oric 1 / Atmos (3 bit RGB TTL)

RGBtoHDMI 6 way IDC 5 way 180° DIN Notes
Pin 1 GND Pin 5
Pin 2 SYNC Pin 4
Pin 3 BLUE Pin 3
Pin 4 GREEN Pin 2
Pin 5 RED Pin 1
Pin 6 +5V N/C

Camputers Lynx (3 bit RGB TTL)

RGBtoHDMI 6 way IDC 5 way 240° DIN Notes
Pin 1 GND Shield Must be connected to both shield halves
Pin 2 SYNC Pin 1
Pin 3 BLUE Pin 2
Pin 4 GREEN Pin 4
Pin 5 RED Pin 5
Pin 6 +5V N/C

Note the 5 way 240° DIN has different pin numbering to the 5 way 180° DIN

Sharp MZ700 (3 bit RGB TTL)

RGBtoHDMI 6 way IDC 8 way DIN Notes
Pin 1 GND Pin 2
Pin 2 SYNC Pin 3
Pin 3 BLUE Pin 8
Pin 4 GREEN Pin 7
Pin 5 RED Pin 6
Pin 6 +5V N/C

Tandy color computer 3 (Analog RGB)

RGBtoHDMI 6 way IDC 10 way IDC Notes
Pin 1 GND Pin 1 or 2
Pin 2 SYNC banded ends of diode pair from Pins 8 & 9
Pin 3 BLUE Pin 5 Blue
Pin 4 GREEN Pin 4 Green
Pin 5 RED Pin 3 Red
Pin 6 +5V N/C

The RGB connector on the CoCo 3 has separate H & V sync but the analog input expects composite sync so you must diode OR the two sync signals together:
Connect the unbanded ends of two 1N4148 diodes to Pin 8 and Pin 9 of the CoCo RGB connector
Connect the banded ends of both diodes to the Pin 2 SYNC input of RGBtoHDMI

48K Spectrum (Analog YUV)

RGBtoHDMI 6 way IDC Spectrum Edge Connector Notes
Pin 1 GND 14B
Pin 2 SYNC 16B same as Y
Pin 3 U 18B
Pin 4 Y 16B
Pin 5 V 17B
Pin 6 +5V N/C

Note Some Issue 1 or 2 Boards may require links fitted to bring YUV to the edge connector

Atom (Analog YUV)

RGBtoHDMI 6 way IDC 10 way IDC Notes
Pin 1 GND Pin 10
Pin 2 SYNC Pin 8 HS
Pin 3 U Pin 7 PB
Pin 4 Y Pin 9 Video
Pin 5 V Pin 3 PA
Pin 6 +5V Pin 2 Leave unconnected if powering Pi externally

Dragon 32 (Analog YUV)

Modifications to create a Dragon external YUV video connector:
Remove the existing 3 pin (5 way) sound and video DIN socket from the power supply board.
Take a 270° 8 way pcb mounting DIN socket and cut off all the solder pins except those equivalent to the ones on the original DIN connector. I used this one:
https://uk.farnell.com/deltron-components/671-0801/din-audio-video-conn-jack-8pos/dp/2989969

Solder this in place of the original DIN on the power supply board.
Connect the following signals to the top of the DIN connector:
6847 Pin 10 (PB) to DIN pin 6
6847 Pin 11 (PA) to DIN pin 7
6847 Pin 17 (+5v) to DIN pin 8
IC14 (74LS86) Pin 3 (HSYNC) to DIN pin 5
Disconnect one end of R65 to disable the colour subcarrier and give mono video on the video output. You can also disconnect one leg of the 4.43Mhz crystal to reduce noise

Your original composite cable can still be plugged in after this mod but you have to reconnect R65 and crystal to get composite colour
If you get 50Hz hum bars try connecting a 470uF to 1000uF capacitor across the 6847 power pins (Pin1 = GND, Pin 17= +5v)

You can now make up the following lead:

RGBtoHDMI 6 way IDC 8 way DIN Notes
Pin 1 GND Pin 2
Pin 2 HSYNC Pin 5 IC14 Pin 3
Pin 3 U Pin 6 6847 PIN 10 (PB)
Pin 4 Y Pin 3 Y
Pin 5 V Pin 7 6847 PIN 11 (PA)
Pin 6 +5V Pin 8 Leave unconnected if powering Pi externally

Pick up the sound from DIN pin 1 to feed to an external amplifier.
You will probably also have to adjust RV2 to set the DC level of the video output so that sync tips are at 0V (It won't lock if they are below 0V) After connecting the the converter, adjust RV2 until you get a locked stable image.

Photo of modified Dragon 32: (This picked up +5v from R3 on the power board)

images/cables/dragon.jpg

PAL Tandy color computer 1/2/MC10 (Analog YUV)

RGBtoHDMI 6 way IDC Internal Connections Notes
Pin 1 GND TCC1000 PIN 1
Pin 2 SYNC TCC1000 PIN 17 PAL HS
Pin 3 U 6847 PIN 10 PB
Pin 4 Y TCC1000 PIN 6 PAL Y
Pin 5 V 6847 PIN 11 PA
Pin 6 +5V 6847 PIN 17 Leave unconnected if powering Pi externally

You will also have to pick up the sound internally via a 1K resistor to connect to an external amplifier

It is also recommended that you power the Pi zero externally for better noise immunity but if you are having issues, try both ways. Also powering externally results in instant video after the CoCo is power cycled.

NTSC Tandy color computer 1/2/MC10 (Analog YUV)

RGBtoHDMI 6 way IDC Internal Connections Notes
Pin 1 GND 6847 PIN 1
Pin 2 SYNC 6847 PIN 38 HS
Pin 3 U 6847 PIN 10 PB
Pin 4 Y 6847 PIN 28 Y
Pin 5 V 6847 PIN 11 PA
Pin 6 +5V 6847 PIN 17 Leave unconnected if powering Pi externally

You will also have to pick up the sound internally via a 1K resistor to connect to an external amplifier

NOTE:
For the NTSC Color Computers you must also remove a capacitor (normally 150pf) on the Y output of the 6847 as it degrades the video signal and will result in a poor quality noisy image.
The component numbering varies depending on the issue of board you have. These are the ones found so far:

Model Model Number Capacitor to cut
TRS-80 CoCo1 26-3002 Not Fitted
TRS-80 CoCo2 26-3026 C59
TRS-80 CoCo2 26-3027 C59
TRS-80 CoCo2 26-3134 C59
TRS-80 CoCo2 26-3136 C59
TRS-80 CoCo2 26-3134A C23
MC-10 26-3011 C33

It is also recommended that you power the Pi zero externally for better noise immunity but if you are having issues, try both ways. Also powering externally results in instant video after the CoCo is power cycled.

LumaCode / Apple II / ZX80 / ZX81 / UK101 / Nascom / Superboard II or any other mono computer

RGBtoHDMI 6 way IDC Phono Connector Notes
Pin 1 GND GND
Pin 2 SYNC VIDEO Video on pins 2 & 4
Pin 3 U GND
Pin 4 Y VIDEO
Pin 5 V GND
Pin 6 +5V N/C

Notes:
The ZX80/81 either require a composite video mod or the 220 ohm resistor mod which can be done as follows:
Open up the modulator and disconnect the wire going to the centre pin of the RF phono connector.
Then connect a 220 ohm resistor from the video input of the modulator to the centre of the phono connector.
You can then plug a phono cable into the modulator to feed the video to an RGBtoHDMI
Note this mod is only suitable for use with RGBtoHDMI as it will not have enough strength to drive a normal video input.

The PAL encoder on the PAL Apple IIe must be disabled (switch on motherboard) and artifact colour will only work with the manual SW2 switch. (NTSC Apples and PAL Apple II+ will auto detect colour modes)

TRS80 Model 1 (Mono) / Video Genie

RGBtoHDMI 6 way IDC 5 way DIN Notes
Pin 1 GND Pin 5
Pin 2 SYNC Pin 3 Picks up mod sync signal
Pin 3 U Pin 5 GND
Pin 4 Y Pin 4 Video
Pin 5 V Pin 5 GND
Pin 6 +5V Pin 1 Leave unconnected if powering Pi externally

An unmodified TRS80 will work but you will have to use the auto calibrate occasionally because the composite sync signal is generated by resistor capacitor monostables which drift with temperature.
If you make the following modification, an alternative sync signal which is timed by the crystal can be output on an unused pin of the video connector and then the auto calibration should only need to be done once during initial setup.
Connect pin 1 (HDRV) of Z6 (74C04) to Pin 3 of the 5 way video DIN socket.

Use the "TRS_80" profile for an unmodified machine and "TRS_80_Modified" for one with the modification.

This modification can also be performed on the Video Genie with the HDRV signal being on pin 13 of IC1 in the Sync Gen (Untested)

Photo of mod on a 50Hz (PAL) TRS80 Model 1 Level II:
images/cables/trs80.jpg

Commodore 64 (with c0pperdragon's YUV interface)

RGBtoHDMI 6 way IDC 4 pole 3.5mm jack plug Notes
Pin 1 GND Body
Pin 2 SYNC Body (GND) Sync is detected on Y
Pin 3 U Ring next to Tip B-Y
Pin 4 Y Tip Y
Pin 5 V Ring next to Body R-Y
Pin 6 +5V N/C

This will only work if c0pperdragon's YUV interface is fitted
See here:
https://github.com/c0pperdragon/C64-Video-Enhancement
Available here:
https://videogameperfection.com/products/commodore-component-video/

The latest 2.7 version of the firmware for c0pperdragon's board has support for RGBtoHDMI built in so if you can update the firmware yourself, you can skip reprogramming the palette below.

Latest 2.7 firmware is here (requires a USB Blaster programmer & software): https://github.com/c0pperdragon/C64-Video-Enhancement/releases

To enable support for RGBtoHDMI on the latest 2.7 firmware, after programming, put a link across pins 9 & 10 of the jtag connector (two pins closest to the back of the case). After that, putting the switch away from the YUV video connector outputs 288p with the special high contrast palette required by RGBtoHDMI so you should use it in that position. To output normal colours use one of the other two positions.

Before link fitted:
Switch towards YUV video connector = 288p
Switch in middle = 576p
Switch away from YUV video connector = 576p with scanlines

After fitting link on pins 9 & 10 on 2.7 firmware:
Switch towards YUV video connector = 288p
Switch in middle = 576p
Switch away from YUV video connector = 288p with high contrast palette for RGBtoHDMI

However it is likely that for the forseeable future the boards from video game perfection will still have older 2.6 firmware so you must follow the procedure below if you are unable to upgrade:

The 3 position switch on the interface should be set to 288p mode (towards the YUV video connector).
After fitting, you must reprogram the YUV interface palette to output a high contrast palette that RGBtoHDMI can discriminate to extract the raw digital pixel data.
This means the analog YUV output will not have 100% correct colours as they will be very saturated but the colours will be correct through RGBtoHDMI

Type the following program into the Commodore 64:

images/program.png

Then RUN it to confirm it outputs the same numbers as below:
(It won't have any effect at this stage)

images/program2.png

Finally to reprogram type:
POKE 53311,137
Press Return
Move the interface switch to any other position and back again to signal you want to reprogram
Then type:
RUN
Press Return
Finally type:
POKE 53311,138
Press Return
The interface should now be reprogrammed with the right YUV levels for use with RGBtoHDMI
(This only needs to be done once, the values are saved in the interface)

To restore normal colours so the analog output can be used with an analog monitor, type in this program:

images/program3.png

NuLA Adapter