ICC Backplane Rev. E mods for SYSCON104

This is the required configuration for ICC Backplane Rev. E to interoperate with Syscon104.

JP1 jumper 1-3 (to deliver +5V to J15-17 req. by syscon)

JP12 jumper 1-3 (ADDRC\)

JP13 jumper 1-3 (ADDRD\)

JP14 jumper 1-3 (ADDRE\)

JP15 jumper 1-3 (ADDRF\)

Jumper JP16.2 to JP3.1 (Expintr detoured to EXPEN0\)

Remove any previous JP16 and/or JP3 jumpers.

JP17 jumper 1-3 (not 1-2) (Expack driven open collector)

Make sure RN27 (10K sip pullup) is installed

Make sure Unnn (HC05) is installed (open collector outputs)

U3-19 and U4-19 must be disconnected from ground and wired

to JP17-2

Design Note:

This last mod is marginal in that it may make some ICC boards non-functional for "write" operations. We used this configuration on the ClONO2 ICCs and found that it worked fine for our D/A boards, but we suspect that it would not work for our old Digio boards. It is possible to make a more complicated mod which will be fully compatible, but that requires a perf board and one or two chips.

To be fully compatible, the data buffers should be enabled when exprd is not asserted or the ICC-side expack (JP17-2) is asserted. This means the data buffers are more-or-less permanently enabled in the write direction, (so write data will be setup prior to the leading edge of the write pulse) and the buffers will only be disabled when reading if the ICC-side expack is not asserted.