29 Aug
2016
29 Aug
'16
10:10 a.m.
On Aug 29, 2016, at 12:33 PM, Rob Jarratt
<robert.jarratt at ntlworld.com> wrote:
You should get the Pro 300 technical manual (two volumes) from Bitsavers. It contains a
great deal of relevant detail.
-----Original Message-----
From: Paul Koning [mailto:paulkoning at comcast.net]
Sent: 29 August 2016 15:08
To: rob at jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: DEC Pro 350/380 Memory Cards - Interchangeability?
just the
On Aug 28, 2016, at 5:11 PM, Rob Jarratt
<robert.jarratt at ntlworld.com>
wrote:
I have a 350 and 380. Neither work. The 380 is reporting a possible
memory error on the LEDs. Will the 350's memory work in a 380 (or vice
versa)?
The 380 has memory on the motherboard, and a model-specific
daughtercard for expansion memory.
It seems reasonable that the Pro bus (I/O card) expansion memory should
work in both models, but I don't have any to try that.
If you have a 380 complaining about memory and it has a Pro bus memory
card installed, I'd suggest removing that card to see if it's happy with stock motherboard memory.
paul
Just reading your reply again. Are you saying it has enough memory on the
board, without using a daughter board? I did see lots of memory on the main
board, but assumed it was video memory. I did try removing the daughter
board altogether at one point, but it still didn't work. :-(
I wish I had a logic analyser. From Volume 1, page 4-4 summarizes the system memory
for both models. Page 5-129 describes the memory daughter cards of the Pro-350. Page
6-125 describes the memory daughter cards for the Pro-380.
I misremembered the 350 (I don't have one): it can have memory in the I/O card cage,
but it also has memory daughter cards, two of them, with 40 pin connectors.
The Pro-380 has main memory on the motherboard. It also supports an optional expansion
card, just one, with a 48 pin connector. The pinouts shown for the two types of
daughtercards make it very clear that they are entirely incompatible.
The Pro-380 also has graphics on the motherboard (though EBO is an option, via a
daughtercard). So a Pro-380 with nothing in the I/O card cage should power up and give
you a display on the screen (presumably one complaining about not having a bootable device
controller...).
On the other hand, the Pro 350 uses a graphics card in the I/O cage, and EBO is a second
I/O card connected to the main one via a jumper cable. Neither of these is compatible
with the Pro-380.
I have somewhere a printout (on 11x17 size paper, roughly A3) of the Pro 380 motherboard
schematics. I haven't seen those elsewhere. I haven't tried to scan them but try
if there's interest.
paul