Intel MDS Series II IOC question

[Tony Duell]

> > > My first thought is SCANBE.
> > > My second thought is SCANBE.
> > > My third thought is... can you guess?
> > 
> > I assume these are cheap and useless IC sockets.....
> > 
> 
> Somehow I had guessed for authenticity purposes, you would be
> campaigning for people to _preserve_ these sockets.  Nightmare-grade
> unreliable sockets are part of the history of the particular machines
> they were installed in.

My policy on repair/restoration has not changed since the last time we 
had this 'discussion' on the list....

A classic computer should, if at all possible, be got working. The 
use of a computer system is to run programs. If it doesn't work, it's 
just a metal box with some chips in it.

However, you should replace as little as possible to get it working. This 
means replacing simple componnts, not whole boards. It also means not 
replacing things _unnecessarily_. 

The electronic design of the machine should be unchanged. In particular, 
replacing the guts of a classic computer with a PC running an emulator is 
not 'restoration' (this does not mean emulators don't have a use in 
preserving classic computers and their software, it just means that an 
emulator is _NOT_ the classic computer). Now, as a hardware person, I 
would claim the electronic design goes way beyond the design of the CPU, 
It includes the peripherals, and the PSUs. BUT, I don't have any problem 
at all with designing plug-in interfaces for classics to modern 
peripherals (doing that does not in any way damage the rest of the 
machine). In the case of PSUs, I'd rather they were kept original. If you 
haev to replace a linear PSU with an SMPSU to save electricity, then IMHO 
the original linera PSU should be kept with the machine (and preferably 
left in place, with the SMPSU hung off the back of the rack!).

I would also do small modifications to improver perfomance or reliabilty. 
I have no problem with filling up a half-stuffed memory board, for 
example. I certainly have no problem with replacing cheap IC sockets with 
turned-pin. If I desolder a programmed chip to dump the contents, I often 
(but not always...) put it back in a socket, and if I do that, I always 
use a turned-pin one.

There you are. My $0.02's worth. 

> > 
> > This reminds me of my Whitechapel MG1. The 'expensive' devices, CPU
> > (32016), FPU (32081), I/O processor (68121 IIRC), etc were all in
> > turned-pin sockets. The EPROMs were in cheap-n-nasty sockets.
> > Replacing the latter with turned-pin so;ved a lot of problems... 
> > 
> 
> I guess you don't view it as an issue.  Were machine-pin sockets even
> _available_ when some of the early machines were produced?

Probably not. But then neither was 74F-series, and I've used those to 
replace 74S in classics. I'd rather use the right part, but if you can't 
get it....

In the case of a rare machine, you should keep a record of all the work 
you've done, of course. If the service manual is in a looseleaf binder, I 
put an extra page in the back with the modifications detailed.

-tony