Notes from the vault 0x07 – occam programming language

Started 25Sep2023. Updated 15Feb2024. This is in group NOTES FROM THE VAULT and Technology

1983 1988 Trademark occam and occam 2 INMOS LimitedThis note will contain some mixed occam programming language stuff.

There is of course more about occam at Wikipedia:

(Aside: not really «of course», since the xC programming language page was deleted because of lack of external references. More here.)

1983 manual

This book is 204 mm wide and 209 mm high. It is not bound, but type loose leaf with a spiral. Copyright 1983 INMOS Limited. OPS-002 000 7/83. It is designed by HSAG Limited. Printed in England by Syon Print Limited. I have seen it nowhere on the internet. I have not tried to get permission from anywhere to publish this book.

It is not paginated but has 50 inner leafs, 100 pages if blank pages are counted. It is printed with black text and figures, and some blue colour text and a green cover. Some introductory pages are very light grey. The graphics (above) is an unoffiocial «occam logo» I designed from the cover of this book and the cover of the occam 2 (1988) manual, for Wikimedia Commons (here). After quite a some consideration it was approved (here).

1983 Programming manual occam by INMOS Limited(Aside: This is not a black and white boring textbook. INMOS paid a lot of attention and money on typography and in producing rather exclusive material. Especially during their first years. This was also seen in the architecture of the buildings they were located in, see Wikipedia Inmos, Aztec West and Inmos microprocessor factory.) This photo I have shot and posted to Wikimedia Commons (here)).

This book describes «proto occam» or «occam 1» I believe.

To actually do something with the rare publication that I had saved all these years, I was inspired by a query on comp.sys.transputer, see Occam evaluation kit user manual?, which I think it perhaps only partially answers.

1983 manual, final scan

  1. I unscrewed the plastic binder and scanned each page at 600 dpi, including the binder holes, into PNG files. The 2.7 GB directory I converted into 1800 pixel width JPG at 90%. You will find these raw files at ../249/ (270 MB)
  2. Then Michael Bruestle at converted these JPG files into a single searchable (OCR) PDF. This is at ../249/1983_proto_occam_manual_INMOS_UK.pdf (73 MB)
  3. also has lots of other occam books and literature at There you will find a searchable PDF with binder holes and empty pages removed, increasing readability, directly at (21 MB)

1983 manual, beta scan

This is scanned at 600 dpi on two different scanners, so each page may vary. These scans contain even the ring binder.  Sources for both are 80% jpg files. No OCR done, ie. not searchable text:

  1. ../249/1983_occam_programming_manual_inmos_beta_scan_600dpi_80pro_by_oyvind_teig_9_2023.pdf (160 MB)
  2. Downscaled the above to max 1800 pixels in any direction: ../249/1983_occam_programming_manual_inmos_beta_scan_x1800_80pro_noblank_by_oyvind_teig_9_2023.pdf (26 MB)

Clean scan

I have scanned the pages as they appeared. It’s a wonder that the book has survived this well out of my shelves, since it arrived on my desk at work at Autronica, some year in the eighties:

  1. Front page: sticker («OTE as»)
  2. Title page: my name
  3. A 2.8 page (starting with «Finally»): two red vertical lines to mark the PAR processes
  4. Page 3.9.1: three horisontal lines

To get a clean scan these must be edited away.

Me and occam

Since occam changed my life there are of course much about it in these blog notes: search here.

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