OOPS -- OOPS on page 10 of the document (Eectec10.pdf), under the J-3 service port, pins # 21, 23, & 25 are listed as "address" ..... I had changed this to "control" but it got lost in the bit bucket summers 8^( those pins are most likely ALE, R and W strobe. conjecture that pin 4 is EPROM disable ??? Tom Cloud