



May 8, 1986


TO: Russ Leefer

FROM: Robert Briody

SUBJECT: Required ECN for ICP8/16 to operate with the 68020 card

Customers in the field upgrading to the 68020 CPU who also have older revision
ICP8/16s will have to have ECN 163 incorporated. Only steps 1a, 1d, 1e, and 1f
need be implemented.

ECN 163 fixed two problems: 1) VME DS0* and DS1* were reversed and 2) VME 
DTACK* was prematurely glitched causing data to be removed from the VME bus
before the Z8002 read cycle had completed. Problem 2 was the cause for older
ICP8/16s non-operation with the 68020 CPU card.

The minimum assembly level for 68020 operation is as follows:
     ICP16     590042-01    Rev.C
     ICP8      590042-02    Rev.A.


Customers having ICP16/8 boards which have had ECN 210 incorporated and NOT
ECN 259 should return the boards for upgrading. Under no circumstances should
ECN 210 be incorporated without ECN 259.

