View Full Version : Microtech M1/34 IRIS Operating System R7 Tape Read

November 11th, 2015, 05:38 PM
I just read what I *think* is the IRIS Operating System R7 install for this Microtech system.

Please see the details, as well as the binary download of the file, on my site at:


It appears to be one single file, 13.7Mb in size, taking up most of the 20Mb tape.

I'm hoping to get Bruce Ray's help to see if I can get this file to run on the DG Nova SimH emulator that he supports. I've played with that some, but I could use a more experienced point of view on how to create a "device" from a file like this to boot from. Does anyone else here have any pointers on that?

About the tape & file, I found a number of strange things that I was not expecting:

1) There is remarkably few readable string-text for such a large file. I would have at least expected to find IRIS, Point 4, or something, but there's only a few lines from utility menus, such as:




And these were near the end of the file. Does anyone have any insight on why these would be the only extractable strings from the binary?

Google finds nothing on those specific numbers, but quoted "MAG TAPE RELIABILITY" (http://bit.ly/1kO4Rmn) brings up some vague articles and documentation on those utilities in the mid 70s and early 80s. Nothing Microtech or Point 4 related, though. The closest I see was mention of the DG Nova in the 1975 computerworld article on BALL computers.

2) The edge of the tape had dates hand-written on it, with a "#LU0" header on the label, and the write-protect was set to "unsafe" when I acquired this tape, so I was assuming that the original IRIS install would have been overwritten with a backup of at least LU0, in the same configuration as I read on the other Logical Unit backup tapes (http://microtechm1.blogspot.com/2015/10/logical-units-vs-positions.html), but it's nowhere even close to that.

3) The format was a very clean QIC-11, different from the weird "Kennedy 6450" format (http://microtechm1.blogspot.com/2015/09/kennedy-6450-tape-drive-data-format.html) I find on the Logical Unit backup tapes.

I could be dealing with different machines here between these tapes, but still my research puts them all in the same context (early Microtech & Point 4 are very strongly related), so it is way too early to come to any conclusion one way or the other.

I'm hoping there's another explanation that I'll uncover along the way.

If this turns out to be the real Microtech IRIS R7 install file, I might have saved something very rare here.

As always, I welcome everyone's thoughts here.


November 15th, 2015, 11:39 AM
Interesting. Let us know how this goes.