Check engine light flashing, car runs fine

I have a 1995 Roadmaster that I bought from the original owner. Car had handycap hand controls that I removed. Car has 56000 miles but was not used much for the last few years. The cars starts, runs, and drives and the only running problem that I can feel is a surging when coming to a stop. This is a motor issue and not a brake pulsation. Possably a misfire when starting out cold but not real bad. My problem is that the Check Engine light is on and flashing all the time. I cleared the code by disconnecting the battery but shortly after restart the light came back on flashing. I took it to a local parts chain but the man tryed a couple times to scan it and came up with no codes and a message saying somthing like cannot connect with computor. I also tryed jumping A & B terminal in the ALDL connector but when I turn the key on I get nothing. The Service engine light does not come on and flash codes like it should and it will not light at all until I remove the jumper. I suspect that I am having a computor problem but I am not sure. Can you help me???