9 Oct
2025
9 Oct
'25
7:57 p.m.
On Thu, Oct 9, 2025 at 2:57 PM Ron Pool via cctalk
<cctalk(a)classiccmp.org> wrote:
I think I have one of these. I fiddled with it when I first got it,
but haven't had a reason to pull it out recently.
From what I recall, you sent specific control codes either from some
sort of hot-F-key memory or by using DOS utilities like XATTACH and
XDETACH to switch ports (I never fiddled with the DOS utilities). It
could be interesting to use as an async traffic switch for file
transfer programs like Kermit, I don't remember how many simultaneous
connections it supports.
Here's a usage manual I pulled up after a quick search.
http://www.bitsavers.org/pdf/dec/rainbow/ms-dos/AA-DY84A-XV_Rainbow_Using_t…
Cheers,
-ethan
I was poking
around eBay and up came a listing for a DEC "mini exchange",
DFMSA. What
is that? The name doesn't sound familiar. It looks like a box with a bunch of DB25
connectors on the back, but that doesn't help much.
See page 4.50 of
https://bitsavers.trailing-edge.com/pdf/dec/catalog/Digital_Networks_and_Com
munications_Buyers_Guide_198710.pdf
From that page:
The Mini-Exchange is a microprocessor-based, standalone, asynchronous
circuit switch designed for local connection of up to eight of Digital's personal
computers...