On Thu, 14 Aug 2003, Henning Kiel wrote:

> It can always do A32. The behaviour does not change if I jumper it to
> enable/disable A24 decodes.

Ok, there are only two remaining options then. 1) You've mis-configured
the jumper settings on the MVME-236, or 2) You're VME backplane needs some
jumpers removed.

For 1), double-check S1 and S2 are set to the following:

	For the card at 0x10000000:
		S1 - All ON
		S2 - All ON except S2.1.

	For the card at 0x11000000:
		S1 - All ON except S1.5
		S2 - All ON except S2.1.

For completeness, S3-S4 should all be ON except for S4.8.

For 2), if your VME backplane has jumpers between each P1 connector (the
top row), they need to be removed if the adjacent slot is occupied.

There are usually 5 jumpers, generally located to the right of the slot
they affect. If that slot is occupied (by an MVME236, for example), all 5
jumpers must be removed.

Not all backplanes have these jumpers; many modern backplanes can
auto-detect the presense of cards and automatically switch the IACK and
bus grant signals accordingly.

Check your backplane's docs for details.

Cheers, Steve