DEC 350

From: Ethan Dicks <>
Date: Thu Jul 4 10:44:46 2002

--- "Jerome H. Fine" <> wrote:
> >Ethan Dicks wrote:
> > > > Those daughter cards can be upgraded from 128K to 512K...
> Jerome Fine replies:
> I have enough difficulty with soldering - the reverse is something
> I doubt if I will ever want to tackle. If I have a change in the next
> few weeks, I will try and look at the memory boards and see what
> I have.

I've been digging through my pile of Professionals this week as a result
of these threads. Turns out I have one nice Pro350 (extended bitmap
card, hard disk controller), one former-console Pro380 and a couple
of diskette-only, lightly loaded Pro-350s (memory and RX50 controller).
For ready-to-go disks, I have an RD50 with P/OS 2.0 (from the console
processor) and an RD51 that won't boot that I _think_ had/has Venix on
it. I will probably scare up an ST225/RD32 for use as an RT-11 disk.

While I was booting the Pro380, the floppy began to seek at a high
rate (didn't sound normal) and the PSU shut down and the white-button
breaker popped. It will not stay in, telling me there's a fatal
short somewhere in the PSU - I was watching it; the VR201 showed the
"d|i|g|i|t|a|l" logo, the RX50 went bananas and it shut down.

The Pro appears to have a spot for a bitmap card or something, on the
front left of the motherboard. Mine is blank. It does have a single
512K daughter card. I pulled it, and dropped it into a Pro 350 for
a test. With one 128K card, one 512K card and as many 256K CTI cards
as I could stuff in there, I got a Pro350 up to ~1.4MB. If I pulled
the RX50 controller (and it didn't whine about that) and upgraded
a 128K card to 512K, presumably, 2MB is about the physical limit of
what fits in there. Since the CTI memory cards are marked "PC 350
Memory", I presume they don't work in the Pro380 (and my testing seems
to suggest that, but I have to re-do things - I appear to have one
256K card that locks up the machine its in).

So... the theoretical (effective) max is 2048K in a Pro350 and 1024K
in a Pro380 (one 512K daughter card and 512K on the motherboard). Does
anyone have any info from the literature to support or refute that?

Also, my extended bitmap card for the Pro350 has a stuck bit and fails
POST. It prints a code which I would post here, but I don't have it
in front of me. I would expect that it's a bad 4164 or a bad multiplexer
or buffer next to the memory area, but I don't want to pull all that RAM
and test it externally if I can narrow the search to a chip or two.

One of my goals here is to put 2BSD on a Pro. Another goal is to set one
up with RT-11. Looks like I have enough parts, but I wanted to consider
the options and figure out between memory and video and processor, which
OS better went with which box.


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Received on Thu Jul 04 2002 - 10:44:46 BST

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