MSV11-J engineering info

Noel Chiappa jnc at mercury.lcs.mit.edu
Fri Jul 6 08:27:08 CDT 2018


    > From: Glen Slick

    > What signal were you probing on the M8186 KDF11-A board?

BDOUT; I'm triggering on that, and without any prints it wouldn't be easy to
find on the MSV11-J. Picking it up off the KDF11-A was the easy way to go.

    > If you run the XXDP VMJAB0 diagnostic and there are failures, does it
    > tell you which data bit and/or ECC bit positions have failures? I
    > suppose it must, otherwise there wouldn't have been much point in the
    > bit mapping exercise.

I dunno; I don't have it. There's also the built-in memory tester in the
bootstrap code in the EEPROM on the KDJ11-B, and according to EK-KDJ1B-UG-001
(pp. 4-24, -26) that prints the address and bad data when an error is
detected.

I have my own little memory diagnostic that I wrote which I tend to use (since
I know exactly what it's doing). I'll probably whip up a modified version to
check the ECC bits in the MSV11-J (in diagnostic mode, they can be
read/written).

The MSV11-J does have this feature where you can leave the ECC enabled on the
low 32KB (or optionally, the second 32KB) even when ECC is turned off for most
of the memory; that's so a diagnostic can live in that memory while testing
the rest. I think I'm probably going to ignore that, and plug in a small
memory card for the diagnostic to live in, since the MSV11-J can be set to
start at any 16KB boundary. That way I can test the entire MSV11-J without any
fancy dancing.

	Noel


More information about the cctalk mailing list