MicroVAX 3300/3400

[Zane Healy]

On May 25, 2021, at 3:09 PM, Antonio Carlini via cctalk <cctalk at classiccmp.org> wrote:
> 
> SII is the built-in DSSI interface. Is it terminated properly?

As best as I can tell, especially after taking it partially apart this afternoon, it is.  The terminator glows green.

> SSC is (iirc) the System Support Chip ... that may be more serious.

At this point, I suspect I have a CPU board that is partially dead.

> FWIW I think the distinction between the 3300/3400 is the size of the box: the innards are the same. (So same as the 3500/3600 and 3800/3900 and the uV3100-30/40 etc.).

I knew that was the case with the 3300/3400, 3500/3600, and 3800/3900.  I feel a bit foolish to finally realize this is the case with the MicroVAX 3100-30/40, and others.

> Both the uV3300 and the uV3400 use the KA640 board.

As Glen points out, there is something strange about this one, as the chassis is even larger than a 3400.

> If you plug KA640 into manx you'll find two useful manuals online.

Thanks, I’m not sure I’ve ever used the site, though I’ve heard about it for years.  I’d found the “KA640 CPU System Maintenance” manual, I hadn’t found the “KA640 CPU Module Technical Manual”.  Hopefully it has some of the information I’m now searching for.

I just pulled out my blue box of fiche (VAX MDS), and verified I have the B400X manual, which isn’t online.  I’ll see about borrowing a fiche reader tomorrow.  I’ve never bothered to get one, I just borrow my Mom’s portable reader, when I need it.

Zane