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DEC EK-DEMSA-RM-001 DEMSA MicroServer Manual

vaxorcist

Experienced Member
Joined
Apr 26, 2012
Messages
96
Location
Germany
Has any one got the EK-DEMSA-RM-001 DEMSA MicroServer Manual (or any other revision)?
There are two links on Manx, but both are broken, and Google doesn't know either ...

And if anyone had a MicroServer to spare in Europe?
Postage from the other continents would be rather expensive.

Ulli
 

cchhrriiss11

Experienced Member
Joined
Oct 19, 2019
Messages
265
Location
Duncan, BC
I also have a DEMSA, but unfortunately do not have the manual... there a few DEMSA's currently listed on Ebay in the USA. I'd also love a copy of the manual if you happen to find one. You might want to reach-out to Paul Williams at vt100.net and see if he still has a copy of the .PDF kicking around somewhere?

If there's anything I can take a photo of, etc with mine that would help you, just let me know.

Mine is a DEMSA-A, not sure if that's the same as what you have?
1683571863636.png

-Chris
 

vaxorcist

Experienced Member
Joined
Apr 26, 2012
Messages
96
Location
Germany
I wish I had one, but I haven't (yet) ...
Have you got a plan what to do with yours?
I'd like to use it for DDCMP synchronous serial networking, e.g. in conjunction with my DSV11 (operational in a MicroVAX 3300) or my DMC11 (untested, planned for usage in my VAX-11/750 (still under reconstruction).

By the way: You are looking for a VAX 8650?
Would a VAX 8600 do as well?
VAX8600.JPG
It's not me on top of the VAX 8600, although I was there, too.
The downside of this VAX 8600 is: it is located in Germany ...
I guess it would take a fortune to get it to Canada.
I haven't got the space nor means to salvage this VAX myself - my VAX-11/750 was in the same place before I bought it.
Just in case you would like it, I can facilitate the VAX - just let me know.

Ulli
 

cchhrriiss11

Experienced Member
Joined
Oct 19, 2019
Messages
265
Location
Duncan, BC
I wish I had one, but I haven't (yet) ...
Have you got a plan what to do with yours?
I'd like to use it for DDCMP synchronous serial networking, e.g. in conjunction with my DSV11 (operational in a MicroVAX 3300) or my DMC11 (untested, planned for usage in my VAX-11/750 (still under reconstruction).

By the way: You are looking for a VAX 8650?
Would a VAX 8600 do as well?
View attachment 1257103
It's not me on top of the VAX 8600, although I was there, too.
The downside of this VAX 8600 is: it is located in Germany ...
I guess it would take a fortune to get it to Canada.
I haven't got the space nor means to salvage this VAX myself - my VAX-11/750 was in the same place before I bought it.
Just in case you would like it, I can facilitate the VAX - just let me know.

Ulli
What do I plan to do with my DEMSA.... hmmmmm not sure yet! It's part of my DEC Networking collection, I've got a bunch of stuff (DECServer 100, 3 DECServer 200's, DELNI, DEMPR, etc) and a number of PDP-11 systems, I was entertaining the idea of doing some networking / DECNET with them.

That's interesting regarding the VAX8600! That sure is awfully really tempting, but the logistical cost would be enormous (many thousands of dollars) I'm sure and I'm guessing it's 50Hz/230V (60Hz where I am)... If I'm looking a that kind of money, I'd rather look at a VAX11/780 :)

Are these cabinets part of the VAX8600 setup as well?
1683594048650.png

I do have a complete board set for a VAX8650, along with the header panel:
1683592817881.png

-Chris
 

vaxorcist

Experienced Member
Joined
Apr 26, 2012
Messages
96
Location
Germany
The cabinets in the background are probably part of the VAX 8600 setup I think.
I did not have a closer look back then, because I was busy to get my VAX-11/750 (rather one 80% complete VAX-11/750 and two rather desolate and almost empty 750s) out of there. These are two of them on my horse trailer:
2 x VAX-11-750.jpg

Nice DEC Networking collection that you have - I'm a little jealous.
I have a H4000 and some H4005, but the rest of my DEC Networking equipment is younger.
I wrote a page about DEC Ethernet Transceivers on Gunkies.

I have two DECnet networking setups in mind:
- An early Ethernet setup using "Yellow Cable"
- A pre-Ethernet (and WAN) setup using DDCMP over synchronous and asynchronous serial lines
Both connected to each other of course.

The DEMSA can connect multiple DDCMP synchronous lines without consuming too much electric power.
The DSRVC (DECrouter 200) can do the same, but for asynchronous lines.
I found out that it is easy to convert a DECserver 200 into a DECrouter 200, and I will do so as soon as I've got one.

Did you know that there is a section about the DEMSA in the EK-CMIV6-RM-005 Communications Options Minireference Manual Volume 6 Ethernet Devices Part 2?
Just in case not I've appended it here.

I think there are even fewer VAX 8600 still around than VAX-11/780. Now I know how difficult in can become restoring a VAX-11/750, I'm happy that I did not acquire a VAX-11/780 (I never had a chance to up to now I must admit) nor even the VAX 8600.

There are some frightening rumors about the VAX 8600, e.g. (I don't know whether they're true):
"We had to have a DEC technician on site 24/7 to keep our VAX 8600s going!"
"You cannot simply but any VAX 8600 boards together to get a working VAX 8600, the board revisions must match exactly"

But your set of boards was probably pulled from one VAX 8650, so they should match.

Have you got other VAXen, especially "classic" ones? I consider all VAXen "classic" that can be run with VMS V4.x or earlier.
My "classic" VAX collection consists of:
- VAX-11/750 (not working yet)
- VAX-11/725 (not working yet)
- MicroVAX I (working)
- 2 MicroVAX II (working)
- VAXstation 2000 (working)

Ulli
 

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