Control codes for Curtis 1243 Controller?

[DWprojects]

Recently I had a replacement 1243 controller sent to me for a cart I am trying to repair. With the flashing error codes I was able to see that the controller was not programmed right. I built an RS232 interface and attempted to communicate with the controller with a dumb terminal program at 9600 baud. I get some responses by sending characters like '$' and ':'
Has anyone had success in working out what the access codes are for changing controller settings?

(I understand that Curtis have a special program for this, but I did not want to buy it just to change 3 settings.)

There must be some special access strings that allow the memory in the controller to be adjusted.