Kevin ( LordTyran <a2k(a)one.net> ) wrote:
> Where can I locate an MMJ-> RS232 adaptor? Or how can I make one?
Dave McGuire <mcguire(a)neurotica.com> wrote:
> I got sick of rummaging for cables last summer. I went over to my
friendly
> neighborhood Graybar Electric store (primarily an electrician/contractor
> supply house) and bought an MMJ crimper and a box of blanks. It set me back
> seventy bucks, but I've gotten a *lot* of use out of it.
Another source for the crimper and connectors is Altex Computers &
Electronics.
www.altex.com
In last year's catalog
Crimper - Stock no 60-3008, $38.59
Connectors - Stock no MP-6D, $31.00/hundred
They also have adapter kits for MMJ to 9 and 25 pin D connectors for $4.50.
A couple of the 9 pin adapter kits might come in handy. I assume, being a
kit, that it comes with the D connector pins uninstalled so you can roll
your own. I say handy because DEC's The H8571-B MMJ to DE9 (female)
adapter is not wired correctly for a typical PC 9-pin serial port.
I always have to hunt down one of my MMJ to DB25 adapters and then a
25 to 9 pin adapter.
-----
In any event, I just recently updated a mini-FAQ on DEC's MMJ. So FWIW,
here is a copy of it.
Mike
Info on the MMJ connector found on various DEC terminals & computers.
--------------- --------------- --------------- ---------------
---------------
DEC uses an MMJ (Modified Modular Jack) connector on its equipment for serial
data communications. DEC calls the mating plug on the cable an MMP
(Modified Modular Plug), only the term is not used as often and most of the
time is just simply referred to as MMJ. It is like a modular telephone
connector, only the key on the connector is offset, not in the center like
a standard telco connector.
Looking at the back of a VT320 for example the MMJ looks something like this.
--------------------
| * * * * * * |
-------------- --
|____|
1 2 3 4 5 6 are the pinout numbers
--------------- --------------- --------------- ---------------
---------------
The signals are:
# I/0 Desc
1 > DTR Data Terminal Ready
2 > TXD Transmit Data
3 - TXD- (ie Gnd)
4 - RXD- (ie Gnd)
5 < RXD Receive Data
6 < DSR Data Set Ready
> = terminal or computer output signal
< = terminal or computer input signal
--------------- --------------- --------------- ---------------
---------------
DEC's part number for the cable is BC16E-xx, I assume the xx may be
the length. The cable is made so that the connector on one end is
mounted 'right side up' and the other end 'upside down'. In other
words, the key tabs on the connector are on opposite sides of the
flat cable.
//
---- ----
| |---------------------------------------| |
---- ----
//
That is effect causes the signal lines to cross-connect or as I like
to say 'turn over' from one end to the other.
MMJ port on DEC MMJ port on DEC
VT320 terminal computer or DECserver
DTR 1 --->-------------->----------------->--- 6 DSR
TXD 2 --->-------------->----------------->--- 5 RXD
3 ---------------------------------------- 4
4 ---------------------------------------- 3
RXD 5 ---<--------------<-----------------<--- 2 TXD
DSR 6 ---<--------------<-----------------<--- 1 DTR
--------------- --------------- --------------- ---------------
---------------
I had a DEC MMP cable that someone cut one end off so I wired it to a female
9-pin D connector to use with a PC 9-pin serial port. Wired as follows:
MMJ DE9
1 6
2 2
3 5
4 5
5 3
6 4
This was to use a PC as the console on a DECsystem 5500 and/or one of the
ports on a DECstation 3100. I actually did not connect DE9-6 to MMJ-1.
It worked fine without it. I later made a breakout box with two 9 pin
D connectors and an MMJ socket along with the means to disconnect and
rewire as needed. I found that it works fine without DE9-4 being wired
to MMJ-6. In other words, using only the two data lines and ground.
Your mileage may vary, depending on how things are setup.
--------------- --------------- --------------- ---------------
---------------
DEC makes several adapters to adapt the MMJ to 9/25-pin D connectors.
The H8571-A and H8575-A are MMJ to DB25 (female) and are wired as follows:
MMJ DB25
1 20
2 2
3 7
4 7
5 3
6 6 & 8
Also pins 4 & 5 of the DB25 are tied together
I have used the above using a standard DEC MMP cable to connect to
a PC 25-pin serial port to use the PC as a terminal.
---------------
The H8571-C and H8571-F are MMJ to DB25 (male) and are wired as follows:
MMJ DB25
1 6
2 3
3 7
4 7
5 2
6 20
---------------
The H8571-B an MMJ to DE9 (female) and is supposedly wired as follows:
MMJ DE9
1 5
2 2
3 7
4 7
5 3
6 6 & maybe 8 (depending on which DEC manual you read)
I have never seen one, so have not actually checked how it is wired.
It should be noted that this is not wired correctly for PC 9-pin
serial ports, besides the gender of the 9-pin connector is wrong.
DEC says that this is used for connecting to 9-pin printer ports.
--------------- --------------- --------------- ---------------
---------------
And here is a summary on how the various signal lines match up to
each other on the different connectors.
Term Term MMJ MMJ port on DEC
DB25 DE9 computer or Decserver
20 4 1 --->-------------->----------------->--- 6
2 3 2 --->-------------->----------------->--- 5
7 5 3 ---------------------------------------- 4
7 5 4 ---------------------------------------- 3
3 2 5 ---<--------------<-----------------<--- 2
6 6 6 ---<--------------<-----------------<--- 1
--------------- --------------- --------------- ---------------
---------------
On Sun, 3 Oct 1999 19:25:40 -0400 (EDT), Bill Yakowenko said:
>What makes you think it is a 6286EL? I know next to nothing
>about these AT&T boxes, so I never would have guessed anything
>besides what it says on the label. Is it just because it's a
>286 box? It quite definitely says "6300 PLUS" on the machine
>itself and on all of the floppies that I got with it.
I have been reading this 6300 discussion for a while, but I still don't
know which computer exactly this is. I know the Italian firm Olivetti
built the 6300 series for AT&T, just like they built a number of DECpc's
for Digital. I only know the original Olivetti's, and can't determine
which Olivetti hides behind the 6300 label. The standard 286 Olivetti
clone systems I have used, always complained about a parity error if there
was RAM memory removed from the system and this was not updated in the
cmos setup. The machine would count through the memory that was there and
generate the error when it fell off the end. Updating the cmos or adding
memory might work. If your 6300 is a 8086 or 8088 then it will not be a
standard clone, Olivetti did things their own way in those days and you
will really need a manual (which I don't have, the first Olivetti's I met
were the 286's).
If it is a 286 Olivetti, then there is no key sequence to get into the
bios setup screen. You need a setup floppy. Some 286 Olivetti's do have
an rudimentary internal setup program, but that only comes up when there
is a problem. To get into that setup I used to unplug the floppy drive
power cable. Even for the 486 Olivetti's a setup floppy was always needed
to get at all the bios setup options. This has always been quite a pain,
since there is no universal Olivetti setup program, each machine has its own.
The exchange program between AT&T and Olivetti also worked the other way
around. I have a 3B2/400 Unix system in my collection (in a part of the
Computer Home I haven't photographed yet, so no picture, sorry) that has
the Olivetti label on it. I don't dare to use it because I don't know the
password, and I do not have any floppies or tapes with the Unix OS for it,
so messing it up would be unrepairable. Besides, AT&T wants a great deal of
money for the maintenance floppies. This machine will alwas have a special
place in my collection though, since it is so heavy I sprained a muscle in my
back while lifting it so bad that I needed several weeks of therapy to cure.
One of the hazards of the old computer collector...
Kees.
--
Kees Stravers - Geldrop, The Netherlands - kees.stravers(a)iae.nl
http://www.iae.nl/users/pb0aia/cm/ my Computer Home page
http://www.vaxarchive.org/ documentation on old VAX systems
http://vaxarchive.sevensages.org/ VAXarchive mirror
Net-Tamer V1.08.1 - Registered
>But if you want to actually run them turned on when they are even two
>high, other than a VT100 (which is what I still use for the first level), I
>have not found another terminal (except for VT100 clones) which allows
>stacking.
The VT52 stacks really well, as does the H19. It's also possible to
unbolt the keyboard from an H19 and replace the cable with a really long
one, which gives you a detached keyboard to set on your lap and a handy
shelf for storing it on when you're not using it.
I once had a setup with six VT52s (two piles containing three VT52s each).
I foolishly built the pile right underneath the thermal cutoff for the
computer room power, so I wound up having to move it.
Roger Ivie
ivie(a)cc.usu.edu
Greetings again!
Having not seen the film 'The Terminator' until a few days ago (on The
SciFi Channel)... I know, I live in a cave, I was very surprised to
see a CDC 924 (or 924A ?) console, complete with Ferranti photo tape
reader evidently hooked-up in some fashion to illuminate the rear-
projection register and status displays. The scene is in the factory
populated with assembly robots towards the film's climax.
I have only seen one other 924 console (in person) in about 1975 at
an electronics surplus salvage yard in the San Fernando Valley, where it
was being used as a workbench!
IIRC, there were only about two dozen 924s made. It was a 24bit version
of the 48bit 1604, CDC's debut commercial product in 1957-58.
Does anyone have a handle on film industry computer archaeology, perhaps
contacts at studios or property shops? For years I've been meaning to
pursue this venue but alas...
I've been compiling lists of film and television shows which showcase
important computer artifacts (one would be surprised at the variety of
significant hardware in 1950-60's TV, especially sci-fi anthology
series. Any additions to these lists would be appreciated.
In addition, we seek newsreel, scholastic and training films which
highlight important information technology (I wish I had followed
school district auctions in the early 1980's when all those 16mm
films of MIT Whirlwind, AN-FSQ/17 Sage, Bendix G-15 Redstone
launch control and the like were discarded.
Michael Grigoni
Cybertheque Museum
On Monday, October 11, 1999 11:05 PM, Grigoni [SMTP:msg@computerpro.com]
wrote:
> A reasonbly good scan of the showcase photograph from a marketing brochure
> for the CDC 924 can be found at: http://www.mtr.webconcept.de/image/
> computer/cdc/924.jpg
The correct URL is <http://www.mtr.webconcept.de/image/computer/cdc924.jpg>.
Michael, when was this machine marketed? The tape drives in the photo look
like 607's, and the chassis is similar to a 6000-series machine.
It's amusing to note that the teletypewriter in the photo is an IBM model.
CDC made some pretty good peripherals, but they didn't try to out-do IBM in
this arena.
-- John
On Monday, October 11, 1999 10:11 PM, Grigoni [SMTP:msg@computerpro.com]
wrote:
> I've been compiling lists of film and television shows which showcase
> important computer artifacts (one would be surprised at the variety of
> significant hardware in 1950-60's TV, especially sci-fi anthology
> series. Any additions to these lists would be appreciated.
There was a Cyber 180-series machine in a Bruce Willis vehicle about an
office building on fire (can't remember the title--I live in a deeper cave
than Michael does). The hardware was actually provided by CDC, although I'm
not sure whether they realized the machine would be destroyed on screen. In
any event, the set dressing was only the machine frame and skins--no
circuitry inside.
-- John
I don't know, but here's a link to an Amstrad site:
http://web.ukonline.co.uk/cliff.lawson/product.htm
-----Original Message-----
From: Rodrigo Ventura <yoda(a)isr.ist.utl.pt>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Tuesday, 12 October 1999 0:19
Subject: Old 8086 Amstrad
>
> Hi. Anyone knows how to enter the BIOS setup in such a PC?
>Does it even have a BIOS setup utility?
>
> Thanks,
>
Hi all
I came across a large, heavy Mitsubishi monitor, C-3910ELP,
manufactured in September 1980.
I want to use it as a display for MAME (arcade game emulator)
in 288x224 mode (NTSC or PAL-type timing), but I can't get
the thing to sync on such a signal.
The monitor has *lots* of pots for setting who-knows-what,
and many many jumpers. Somebody might have fiddled with it
before as well.
So, anybody know anything about this beast? I can put up
pictures if required.
Thanks
Wouter
I've got a small pile of Amiga magazines available.
The pile contains most issues from 1991 through and including 1994,
plus a couple issues outside of that range. There are also about
a year's worth of Amiga Computing magazine which seem to be from
1995 and 1996, but sport a bewildering variety of issue numbers and
dates, with very few having both an issue number AND a date, and
with issue 2 following issue 87 (those two had both)...
Make offers. If the highest valid offer is less than double the
lowest one, the first one to arrive is the one that wins. The
intent is FCFS unless somebody really _REALLY_ wants them. Valid
offers are those that meet or exceed the cost of postage. :-)
I'll wait until noon on Thursday to decide.
You could also look at my "wanted" web page and offer things from
there, in which case I'll have to decide whether I'd rather have
that or the money:
http://www.cs.unc.edu/~yakowenk/classiccmp/wanted.html
Cheers,
Bill.
