AlphaStation 200 NVRAM Problem

[Maciej W. Rozycki]

On Mon, 2 May 2016, Robert Jarratt wrote:

> I decided to attempt the construction of an adapter. But it is the
> connectors which always bite me because I don't know what all the types of
> connector are. I naively assumed that an IDC 10-way (2x5) would do the
> trick, but it is too wide to go into the male connector on the board.
> 
> What kinds of connectors exist for ribbon cables that can be used to go into
> a 2x5 connector, but which don't have  a lot of space at the sides?

 I think this header is intended for a crimp wire receptacle, like: 
<http://uk.rs-online.com/web/p/pcb-connector-housings/8215708/>.  This is 
non-polarised though; getting one that is polarised and with the right key 
might be a bit of a challenge.  Alternatively a PCB socket like: 
<http://uk.rs-online.com/web/p/pcb-sockets/7655648/> would do too; again 
getting a polarised one seems tough.

 I don't know which of the two solutions the original DEC SROM "dongle" 
used.  I can only find 3 references quoting the part number, which is/was 
96-RM001-01.  It provided for a standard DECconnect cable, so I think it's 
actually quite likely that it was just a small daughtercard with a PCB 
socket, line driver and receiver ICs (DEC documentation quotes 1488 and 
1489, but with a pair of wires used for communication that looks like an 
overkill to me -- a single IC like MAX232N would do IMHO; RS sell them 
individually even) and their associated passive components, and then an 
MMJ socket, all on the PCB.  Obviously these days you probably want a DE-9 
connector instead. ;)

 I wonder if I shouldn't actually make something like this myself just for 
fun -- to have a way to peek at my DEC 3000's internals even though it 
appears healthy overall.

  Maciej