Replacement of game rom Gottlieb system 1.
I would like to thank David Wallerich ( France ) , who provided me with some essential data concerning the rom images.
The game rom of Gottlieb system 1 machines is an old 1024 x 4 bits type, completely obsolete.Impossible to read on any modern eprom programmer. Of course it is possible to make an adapter socket to read the rom .Anyway that is no help , because there are no new roms to find and no programmer who can burn them...
As the roms are obsolete we only can replace them by a more common eprom type 2716 and are forced to make an adaper socket that fits into the original socket on the board. The 2716 is a 8 bits eprom , and of a capacity twice the original. The image that has to be placed in the new 2716 rom is therefore different of the original Gottlieb image. In a way that suits us as we are not dependent of the copyrighted Gottlieb image.. I did make the possible 16 images that will fit into the 2716 and will run your game as the original rom did .You can find the 16 different game roms here .....
To make this work we need a adapter print, there is no way around that.Those who cannot make a printed circuit will have to buy one, the 3 components that will fit on it are easily to be found anywhere. With some soldering skills every one can realise the very compact mounting.
Mail me if you need the bare print, only 15 euro postage included....
Those who can make the printed circuit, here is the lay-out.
The inner 18 islands receive the pins that fit into to existing rom socket, the outer 24 pins receive the new 24 pins socket for the 2716. The (red) capacitor is 100nF and is between 0 and 5 volts, there is one jumper marked with a red line.
Solder first de pins, then the socket, and at last the condenser and the jumper.
Here some photo's how things are mounted , pictures says it all .
Solder first the 2x9 pins , in the inner row of islands, at the underside of the print..
Now solder the 2716 socket , the jumper and the condensator.
Burn the image you need into the 2716, place it into the socket, and the whole on the CPU board at the place of the original game rom.
The replacement mounted. The PCB is mounted with the condenser downwards , the notch of the 2716 ( pin 1 ) is upwards.That is the right manner to mount the whole thing.