Thanks AGAIN to Al Kossow of bitsavers.org and Dick Toepfer for providing these!
The CTIX operating system is derived from AT&T's UNIX System V, Release 2. That is, it is a virtual memory implementation of the System V user and programmer interfaces. In addition, certain features of 4.2 Berkeley Software Distribution (BSD) have been incorporated. In particular, the interprocess communication facility known as sockets has been partially implemented under CTIX

Clarence Dold
Software Support Engineer
Convergent Technologies
1984 – 1993 (9 years)

said, in a Google+ Hangout Chat on August 23, 2014:

"What kernel changes were made from UNIX System V Release 3 to support CTIX for the MightyFrame? The Mightyframe ran SysV 2.2, never SVR3."

We see more evidence of Release 2.2 here in the :
MightyFrame™ Overview

The 2nd bullet point on the left:

"Industry Standard UNIX™ System V, Release 2.2 operating system with 32 MB demand-paged virtual memory"

CTIX related Brochures:

CTIX Operating System - May 1988 (brochure)
(we currently believe that this version of CTIX was never implemented on the MightyFrame, and was likely used only on Convergent's newer systems


 ( on QIC-24 3M DC 600A cartridges or equivalent )

Photos Courtesy Michael Herzog - Many Thanks!

In July 2014, Al Kossow of the Computer History Museum found a box of CTIX labeled carts at a flea market.  Unfortunately, all of the MightyFrame-specific tapes were "written over with accounting backups."


Does anyone know of others?

If you have anything that remotely resembles this, please contact us at MightyFrameCT@Gmail.com 

On 11/25/2013 Michael Herzog emailed a screen dump of his "most successful" experience using one of these tapes:

Michael's MightyFrame is a CR-6140-A11

This happens when he tries to boot his CTIX 5.23 tape:

executing loader from tape

MightyFrame I loader version 12
booting from tape
                *                                             *
                *                                             *
                *        WELCOME TO MIGHTYFRAME CTIX          *
                *                                             *
                *                                             *
                *   This is the software raw install tape     *
                *                                             *
                *   It should be used ONLY for new systems    *
                *                                             *
                *                                             *
                *   CONTENTS OF YOUR DISK DRIVE               *
                *                                             *
                *                                             *

Do you wish to continue and install
        the CTIX software on SMD drive 0 ('yes' or 'no')? yes
iv: opening special file /dev/rdsk/c1d0s0: No such device or address
Hard Disk is not formatted
Type 'yes' if you wish to format drive? yes
/install/RawInstall: test: argument expected
MightyFrame PROM Version 1.3
available memory:0x300000 mapped as:C1
memory frames 100 - 200 not present
memory frames 200 - 300 not present
memory frames 300 - 400 not present
memory frames 400 - 500 not present
memory frames 500 - 600 not present
tape status:90810000 WP RESET

-------------- cut

And THIS happened with the maintenance tape:

MightyFrame PROM Version 1.3
available memory:0x300000 mapped as:C1
memory frames 100 - 200 not present
memory frames 200 - 300 not present
memory frames 300 - 400 not present
memory frames 400 - 500 not present
memory frames 500 - 600 not present
tape status:D0810000 WP NOCART RESET
tape status:D0000000 WP NOCART
CTIX was not running - no dump needed
checking memory at 600000 [ addr ~addr parity ]
checking memory at 700000 [ addr ~addr parity ]
tape status:90000000 WP
tape status:0
tape status:91000000 FMFOUND WP
executing loader from tape

MightyFrame loader version 11
booting from tape

                MightyFrame CTIX Maintenance Tape

Your hardware inventory is:
3145728 bytes memory
16 maximum users
controller #2 drive #0 drive #1

You don't appear to have ANY disks.
Either power off the machine and fix/add an ST506 drive (winchester)
or load the EEPROM with the address of your SMD disk controller.

WARNING - do not execute fsck before adding a swap partition
Once a drive is usable add a swap partition by:
        swap -a /dev/dsk/c0d0s2 # (for ST506 drives)
        swap -a /dev/dsk/c1d0s2 # (for SMD drives)

followed by a
        swap -d /dev/dsk/c2d0s2

The terminal modes have been set for an upper case only terminal.
  You may wish to enter a 'stty -lcase' to set the modes back to normal.

# <-- Yes, it was a shell. a REAL shell.

I know about the hardware and the software, I got it installed ages ago. But by now, most
of the tapes are broken, and there was no way to copy them (bit shifting caused error on
normal QIC drives - I have cipher, wangtek and scorpion to try, nothing at all), even the
tool "tprobe" does not work. It uses 2 3 7 on the console port for normal connection, when
powered on it should bring up a message like I posted before, with memory test. Does
your MF contain a hard disk drive? There are only a few that will work, like Seagate XT-4096
or Micropolis 1325.... - I dont have any working hard drive....still looking :( Also, still looking
for some tapes to copy.

I restored the internal tape drive (the capstan can be replaced by rubber wheels used in
normal audio tape drives!!!), and tried to read them out - it did not work. The blog is a good
idea, if you need additional webspace, feel free to tell me, I have several GB "empty".

Cheers, Michael


It would be fantastic to find CTIX and/or MightyFrame manuals also.  
Here's what Google turns up today:

Most interestingly, she states that she "Revised AT&T UNIX documentation to support CTIX software".  Does this imply that CTIX was built on top of the AT&T UNIX PC unix?


Louis Meadows, Software Support Engineer at Convergent from June 1983 – August 1986
says in an email to us on 8-28-2014:
"CTIX was CTOS plus unix interface, we also built a unix 5 station for at&t I think that was called the 7300, but it's been a bit."

His LinkedIn profile reports that he "Developed assembly, C, PLM code for CTOS / CTIX (UNIX) development of custom data communications drivers."


Evan Leibovitch, user of the Megaframe, said to us in a message on 4-20-2014:

As I recall, the Megaframe and Mightyframe were very different systems. The Mightyframe was a later model that ran CTIX (Convergent's version of System III Unix) natively, while on the Megaframe it ran on top of CTOS (https://en.wikipedia.org/wiki/Convergent_Technologies_Operating_System)
My system actually had three motherboards; one had the main Motorola 68010 CPU that ran the Unix. But the I/O Boards -- one for the SCSI interface for disks and tape, the other for the serial ports (no LAN) -- both ran Intel 80186s CPUs running CTOS.

Under normal circumstances the Unix operator would never have to see CTOS, there were a few Unix commands (which I forget right now, I seem to recall them as ioctl switches) that performed the interface from Unix to the CTOS-based I/O system. (Occasionally for low-level hardware work (ie, formatting drives) it would need to boot into CTOS directly.)

The system would always need to load CTOS into the I/O boards before CTIX could load on the main board. (Bootups could take a while, but once booted it was fairly vanilla Sys3.)

The theory was that with the SCSI and serial using their own dedicated motherboards and OS, the main CPU would be free to do number crunching, database work, etc on its own. In practice it was just one really complex system.


Support Manager at Convergent Solutions Ltd., Great Eastern Street, London
October 1983 – March 1985 

LinkedIn Profile:  "UNIX porting experience and comfort with hardware was useful for a UNIX box shipping operation (Convergent Technologies MiniFrame & MegaFrame)."

Jeremy Chatfield on August 19:

IIRC the Convergent OS tapes weren't tar, they were 'cpio'. That was a different archive format, incompatible with 'tar'.


Bill Funk in an email on 9-2-2014:

From my experience, messing about with other UNIX variant installation technologies is fraught with peril. All variants after all are ports of some brand of UNIX, SVR4 or BSD, to specific platforms. CTIX was no different; even amongst the 'frames.


It's starting to look like CTIX had different iterations at different times, for different machines.

So what is the connection between CTIX And Berkeley UNIX?  Berkely Software Distribution?

So far, I've heard that CTIX was layered on top of CTOS for the MegaFrame, then derived from UNIX V rel 2.2, and another for rel 3 (but the MightyFrame never ran that one).

I will assume that Evan's comment about UNIX System III was simply mistaken, all other indications point to different release of only UNIX SysV.  But, hey...additional information is still surfacing, there could be something to that.

I suppose I should create a timeline for these machines and overlay the contributor's dates served at Convergent.  That could show a correlation.


Back in the day, SunOS™ did something very similar

We have also posted this request at the vintage-computer.com forum

...and on Unix.com at bit.ly/1nAWF5J 

...and on Dev Shed Forums bit.ly/1hFy9eQ and bit.ly/1sAixAk

...and post on old-computers.com when registration complete (or not...)

...and on Reddit UNIX