> On Aug 29, 2016, at 12:33 PM, Rob Jarratt <robert.jarr...@ntlworld.com> wrote:
>
>
>
>> -----Original Message-----
>> From: Paul Koning [mailto:paulkon...@comcast.net]
>> Sent: 29 August 2016 15:08
>> To: r...@jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts
>> <cctalk@classiccmp.org>
>> Subject: Re: DEC Pro 350/380 Memory Cards - Interchangeability?
>>
>>
>>> On Aug 28, 2016, at 5:11 PM, Rob Jarratt <robert.jarr...@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
> just the
>> 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.
You should get the Pro 300 technical manual (two volumes) from Bitsavers. It
contains a great deal of relevant detail.
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
