╔ JUST GOT OFF ╒╙┼╬┼╘ WHERE ╔ READ A MESSAGE FROM ╞RED ┬OWEN OF ├┬═ THAT DESCRIBED THE 1581 PROBLEMS AND THE OFFICIAL FIXES FOR THEM. ╘WO PROBLEMS EXIST. ╨IN 10 OF ╒10 WAS NOT PROPERLY GROUNDED IN SOME UNITS DUE TO SOME UNMODIFIED PRE-PRODUCTION BOARDS SNEAKING INTO A FINAL PRODUCTION RUN. ╘HE NUMBER OF AFFECTED UNITS IS ABOUT 500. ╘HE SYMPTOMS VARY FROM OCCASIONAL "DEVICE NOT PRESENT" ERRORS TO DATA NOT BEING WRITTEN OR RETRIEVED FROM THE DISK CORRECTLY. ╘HE FIX IS TO GROUND PIN 10 OF ╒10. ┴ SERVICE CENTER *╫╔╠╠* DO THIS FOR YOU SINCE THEY HAVE ALL BEEN NOTIFIED.
╘HE SECOND PROBLEM IS A BAD LOT OR TWO OF ╫─1770-00 CONTROLLER CHIPS. ┴BOUT 2000 UNITS ARE AFFECTED. ╙OME (NOT ALL) DRIVES USING THE 1770-00 CONTROLLER CHIP (╒4), OCCASIONALLY DID NOT CORRECTLY WRITE DATA TO DISK. ┴ CORRUPTED DIRECTORY FOLLOWING A DISK COPY IS A TYPICAL SYMPTOM OF THIS PROBLEM. ╘HE FIX IS TO REPLACE THE ╫─1770-00 WITH A ╫─1772-00. ╘HE 1581 WAS DESIGNED TO USE EITHER ONE AND, IN FACT, THE VAST MAJORITY OF SYSTEMS DID USE ╫─1772 CONTROLLERS. ╞RED RECOMMENDS THAT A SERVICE CENTER DO THESE REPAIRS SINCE ╒4 IS NOT SOCKETED.
╞RED ALSO STATES THAT JUMPER ╩1, PHYSICALLY LOCATED NEXT TO ╒4 SHOULD ┴╠╫┴┘╙ BE SHORTED WITH A 47-OHM RESISTOR FOR A 6MS STEP RATE.
╔'M UPLOADING A PROGRAM WRITTEN BY ╞RED THAT WILL ALLOW YOU TO DETERMINE WHICH CONTROLLER YOU HAVE AND THE STATUS OF THE ╩1 JUMPER (OPEN OR CLOSED). ╘HE PROGRAM WILL BE NAMED "1581.DIAG"
