IRIS and SimH on alt.folklore.computers - from 2006

From a newsgroup thread called Looking for Johnson's pcc - DG Nova and Eclipse

This seems to contain some good IRIS OS overview knowledge from the perspective of an experienced past user, (possibly) John L Wright, Jr from Arargh.com

http://domainiac.tech/reviews/arargh.com

http://www.whois.com/whois/arargh.com

The thread was written 10 years ago, almost to the day, but hopefully still contains relevant info about the IRIS environment.

Here are the IRIS-relevant extracts from that:

Arargh.com:
Another issue, do I write it for the only Nova OS that I have (IRIS
from EDS, later Point4) or standalone?

Also, write for a stock Nova, or the modified clone processors that I
have.  The ones I have support 64k words of core, but you lose the

LDA/STA memory indirect chaining feature.  But they will run as stock.

Wild Hare's reNOVAte Demo Version 4.0B.06

We are attempting to use a demo version of reNOVAte, a DG-style emulator produced by Bruce Ray at Wild Hare Computer Systems.

http://www.wildharecomputers.com/products/renovate.php

The demo version was downloaded from this page:

http://www.novasareforever.org/downloads/downloads.htm

We are using the "Win/95/98/Millenium/NT/2000/XP" version.

Bruce has very kindly and generously provided us with a software key to use this demo version.

An old version of the reNOVAte manual can be found here:

http://www.novasareforever.org/downloads/reNOVAte.pdf

We are trying to use this version to re-create the successful running of the program "Minicom Disk To Tape Copy Utility", that Bruce demonstrated in screen shots, shown here.

Minicom Disk To Tape Utility tells a story...

Microtech Dart Utility Rev 2.6

We have just successfully read the Microtech Dart Utility Rev 2.6 QIC tape cartridge.

The format is a very clean QIC-11, with 24 files, and all files fit on a single track (Track 0).  We used our own invented process to read this tape, documented here.

The first file is 512 bytes, the second file is 20480 bytes, and all of the rest of the files are 46080 bytes.

This one seems to actually be what is on the label: an original install program.  Also, this is the only tape of any tapes in our sets of tapes, where we can actually find any instance of the word "Microtech".

North West Computer, STAR Computer Group, Inc. & Ivor J. Lee, II - Jim Lee

On the IRIS Tape, we found this excerpt of a letter:

Star Computer Group, Star Technologies, and Microtech Business Systems - Incorporation Records

We are culling this information from public records, in order to gain more of a firm timeline on these machines, and the contents that we are finding on these tapes (dates, company names, etc.)

Star Technologies is sometimes displayed as Star*Technologies

Dropping the Highest Order Bit

John Svee at Data Conversion Resource / Trusted Data Solutions found one of our posts/pages at this site, and has provided us a GOLDMINE of knowledge, as to how to decipher the data that I've extracted from all of the tapes that I reference as part of this Microtech / Point 4 restoration project.

Here it is, in his own words:

To whom it may concern,

When doing research for a current project involving 4-track QIC tape data (DC-300 tapes) I came across “http://microtechm1.blogspot.com/2015/11/microtech-m134-iris-r7-tape-read.html”.

I downloaded and worked with the tape file (IRIS-Track 0Fthru2F-whole file.bin) and made some observations.

1.) Some data is readable ASCII as you pointed out.

Minicom Disk To Tape Utility tells a story...

Bruce Ray at novasareforever.org actually was able to get this utility file to RUN!  

The raw binary file can be downloaded from here: http://bit.ly/1NklvGj

(Reference my original page with the MINICOM DISK TO TAPE UTILITY)

Here's how, in Bruce's words:

The tape contains a disk/tape backup/restore utility that is somewhat representative of those used with Point 4, and other 3rd-party DG lookalike systems. It is a stand-alone utility that is bootable if it exists as the first record of the first file of a mag tape or cartridge.

The usual procedure is to bootstrap the tape using the Nova APL function (or just toggling in simple 2-instruction 'fat-finger' program).  Once the program is read into memory, it starts execution and displays its introductory message.  At this point another tape/cartridge may be loaded onto the tape drive for backup or restore purposes.

I used our reNOVAte software (see reNOVAte manual) for doing my investigations rather than SimH due to convenience, and was able to run the program and exercise its various functions.

Microtech M1/34 IRIS Operating System R7 Tape Read

The tape has QIC-11 formatted data across the first 3 tracks of the tape, and appears to be all one file, (with only one filemark at the end of the data on the 3rd track).  Track 4 appears to be blank.

It's approximately 13.7Mb file, and it can be downloaded for analysis here.

LOTUS CACHE MEMORY DIAGNOSTIC PROGRAM

In reverse-endian from the rest of the file, I found yet another utility:

LOTUS CACHE MEMORY DIAGNOSTIC PROGRAM
REV 1.1  FEB 4,1982

Here's a download of the full binary extraction from the entire Track 0 with the endianness exactly as it was on the tape, and here's a reverse-endian version which more clearly revealed this text.  

This text extract begins at address 0xC2620.

Logical Units vs Positions

Written on every Microtech backup tape we have is a nomenclature of Logical Units and Positions, such as "Logical Unit 0, position 1", or abbreviated:  "LU 0, pos 1;"... and so on, or some mixture thereof.

Click to see pictures of all tapes on Google Drive

I've been told by those more familiar with this vintage technology that I should think of Logical Units as hard drive partitions.  But then what do the positions mean?  

Google wasn't any help to me on this.  Searching the phrase that now is the title of this post revealed nothing that really matched.  So, I was left to guess.

And, well, maybe I was looking at it the wrong way.  I was thinking that the Logical Units and the Positions both had to do with the hard drive, but maybe this excerpt from the MTCopy manual sheds some light on this.

Point 4 MTCopy User Manual Rev 2a - page 14

Interesting how it says "Each tape in your set of backups will contain the bootable portion followed by the individual logical units."

So, maybe the Logical Units represent the partitions on the hard drive, but the positions represent the position that the Logical Unit is now holding on the QIC tape.  Could this be it?  I'm starting to think so.

I wondered why LU 0, 1 and 2, corresponded with Pos 1, 2 and 3, but LU 3 and 4 corresponded again with pos 1 and 2 instead of 4 and 5, but if the position means the position on the tape, and has nothing to do with the position on the hard drive, then this makes sense.  LU 3 is the first file after the BOOT file on the 2nd tape, so it is pos 1.

Mystery solved...I hope...

Bruce Ray on emulating a Point 4 system

From October 14, 2015, to me by email:

The standard Point 4 Mark x instruction set was compatible with the "classic" DG Nova instruction set, and each company added additional instructions over the years.  DG added additional instructions to the "classic" Nova set starting with the Nova 3 and Nova 4 - primarily stack and byte operations.

Peripheral controllers could be program-compatible or divergent, it just depends upon how the computer is configured.  Some Point 4 systems (the Mark 2/3) had some integrated disk/tape/multiplexor peripherals that were total incompatible with anything else, and therefore required special knowledgeable programming.  Other configurations we dealt with used the Lotus 700 series controllers which could be compatible with certain DG disk and tape drives (but had extended capabilities).

EDS/Point 4 created a higher-performance terminal multiplexor that was not DG compatible, but we have also seen Bytronix and CSI (Custom Systems) multiplexors in client systems (and therefore support them in our commercial reNOVAte product).  Of course, "standard" DG-compatible multiplexors could be used in Point 4 systems as well.

So the procedure we use when receiving a client "mystery tape" is to boot the tape and dynamically trace the user program program to determine what device(s) are being accessed.  Then, depending upon the device codes and I/O instructions used (and a bit of our decades of experience with these systems), we can guestimate what controller and disk device is assumed by the user program.

The SimH Nova emulator can emulate some of the possible IRIS configurations, but "it just depends".

Most of the IRIS-similar backup utilities (disk-to-tape-to-disk) were simple sector copy programs, usually the entire disk (or a LU subset).
MCT (MiniComputer Technology), Lotus, and Rianda controllers were popular 3rd-party products in the '70s and '80s.

I have enclosed information for the tape/disk copy programs for your entertainment

POINT 4 DISK SUBSYSTEM UTILITY & LOTUS 700 DISK CONTROLLER DIAGNOSTICS

On the next Microtech backup tape that I am restoring, 
( Labeled LU0-pos1; LU1-pos2; LU2-pos3 ), 
on track 0, I found these 2 segments with text in "English":

POINT 4 DISK SUBSYSTEM UTILITY
VERSION 1.4 SEP 17 1980

LOTUS 700 DISK CONTROLLER DIAGNOSTICS
VERSION 1.7 JAN 31 1981

I'll be posting the full text versions soon, along with my guess of the full binaries.

Here's a download of the full binary extraction from the entire Track 0.  Note, I added my own artistic interpretation to delineate filemarks.  Just search for the text "filemark" in your hex editor/reader.

Does this give us better clues as to what model, vintage, etc of Microtech machine that these once backed up?

Kennedy 6450/6455 QIC Tape Drive? - Data Format Analysis

Please also visit QICreader.com

Could the Microtech DART / M1 we are reconstructing once been equipped with the Kennedy 6450 Tape Drive, or equivalent?   Here's some clues:

On one of the tapes is written "Kennedy Backup Disc Utility".  Well, does that mean that the Disk being backed up is a Kennedy, or that the Backup Device, for which the Utility was made, is a Kennedy?  Or both?

Point 4 Connection

"The Microtech used the Point-4 CPU until 1982 when Microtech merged with Star*Technologies, and then a new proprietary CPU was designed. Microtech's IRIS OS was licensed from Data General or Point 4, but was Microtech's own version."
-Michael Marselle,
 Applications programmer / Technical Support
 Microtech - Prior to merger with Star Technologies
 1982 – 1984 (2 years) Costa Mesa, CA

Dan Paymar read this page, and offered this clarification to Michael's quote above:
"Although the original BASIC interpreter was written by me (as VP of Educational Data Systems) for Data General, the timesharing system was strictly an EDSI product, and later IRIS was strictly a Point 4 product. None of it could have been licensed from Data General."

------------------------------------------------------------------------

Now, we wish we could say that we possess any of the hardware that we picture below, but alas, we do not.  We have culled these pictures from various sources, and we do our best to cite each source under each picture.  Enjoy!

Point 4 Computer, 1979
This is the original.  No "Mark" anything.  It predates the "Mark" nomenclature.

Point 4 Computer User Manual, 1979, page 14

Point 4 Computer User Manual, 1979, page 109

MINICOM DISK TO TAPE COPY UTILITY

Using the method I developed for reverse-engineering QIC-24 tape format, I have begun to read these old tapes from what I'm guessing is a POINT 4 Mark V or VIII (Mark 5 or 8) system from 1981-1983, re-branded as a Microtech M1.

First on my agenda is researching the first file on the first tape that I read:

MINICOM DISK TO TAPE COPY UTILITY 

The raw binary can be downloaded from here: http://bit.ly/1NklvGj

Since nobody I've talked to yet knows of an operating Microtech M1, I'm wondering if anyone here has ever used Minicom from the early 1980s?  

Here's the only "English" extracted text from the binary: