Feb 10, 2021

Pong game RGB Mod

This console was made in Hong Kong and sold under many names like Grandstand, Soundic, Hanimex or as in my case MARK (Prelude Modell 64562).

My first attempt was to make a Composite video mod. This resulted in a horribly noisy video output. After some investigation I realized that it is easy to make an RGB mod for this console since it has separate signals for sync and the graphical elements. The signals are provide by the "AY-3-8610" chip in the cartridge. This is a single-chip-game that is called Supersportic or PC-501. It has 8 Pong style games and 2 that requires a rifle. I mapped the colors as close as possible to the original except for the background that I made black mostly because it was easier. But I think black is kind of cool. I may go back and add an option to make it green later. That would require a 3 input NOR gate...

Image captured from the console.

Below are some notes that may help if you are going to do a similar mod. I also removed the RF-modulator board and replace most of the capacitors. I accidentally blow up a 1N4148 diode before I realized that positive voltage from the external 9V PSU is ground for the circuits on the board! 

This is the result!

This Scart cable fit in the old RF output hole.
 
These are the connection point on the main PCB.

 
This is the schematic for my connections. The reason for using a 40106 schmitttrigger inverter was that it was what I had at hand. A regular inverter should do just fine. I had no OR gate chip so I used two schottky diodes.


Output amplifier and audio scaling.
 

Logic for color mapping.

 

 

15 comments:

  1. I cannot sleep for 3 nights. How to make background color? Where you take background signal if background chip on cartridge is not connected to any slot? Please help me! and thanks!

    ReplyDelete
  2. When none of the other signals are active it is the background.

    ReplyDelete
  3. Then if a put signals 12,13,14 (Boundaries, P.right and P.Left) through a 3 Gates input NOR, the output goes to green signal of RGB Scart map... I’ll have green background as original?

    ReplyDelete
    Replies
    1. Done, putting 12,13,14 (Boundaries, P.right and P.Left) through a regular inverter and then thought a 3 Gates input NOR, the output goes to green signal of RGB Scart map... I have green background. BUT only works with super sportic and Motocicle with other games have strange colors

      Delete
    2. I think that this may be caused by the fact that one of the pins 12, 13 or 14 is unconnected in the cartridge. A week pull/down might solve it.

      Delete
    3. I think that we map by wrong way. There is more than one way to map a game. Maybe there is a common map for all games that is not the one that we are using now, and
      I think that the end of the question is the background.
      When I disconect all signals from RF board screen in green . Maybe background green is always control by Soundic not by game

      Delete
  4. Would somebody have a sumary schematic of all that ?

    ReplyDelete
  5. These kinds of mods are viewed as second rate compared to different sorts of regulator mods since you generally need to hold down the catch for the rapidfire to work. Kinemaster Pro APk

    ReplyDelete
  6. Can't understand what you are writting Bennie !
    Danaellinux would you have a whole schématic for moding this pong ?
    Thanks

    ReplyDelete
  7. It's a complete headache. Pins are connected in all games. I map colors on SuperSports perfectly. But on other games do not match.
    Fabrice I have been work on this for 6 months I do not have success. I change scquematics all days. When I have something stable I'll try to publish it. My be try to open a new Discord to share knowledge

    ReplyDelete
    Replies
    1. I'm also scratching my head. I have a suggestion I'm working on... May be the background is given by the clock pin of the cartrigde (pin 4). Strange but this console is really weired ! This worth a try.

      Delete
  8. oh! I'll try too. but take a look to the pins that goes to the RF module, that are the real signal pins. As Patrick says not all games uses al cardrige pins. In fact pins 10 and 11 from RF board goes to clock

    ReplyDelete
  9. I think I found the point where to solder the green background. It is situated on the dauther-board. The late problem is that the signal even if clear, objects are thick shadowed... and I don(t kniow how to correct this. Give me your contact I will mail you a picture Danaellinux.

    ReplyDelete