"Micro fiche" is one form of film based document archival and distribution system (see "Microform" on Wikipedia).
Document pages were transferred to 105 x 148 mm sheets of high resolution film. A single sheet can contain up to 13 x 16 = 208 pages. And it has a wonderful blue background color! (Find a desktop wallpaper in the attachement)
Micro fiches in the field
As all major companies, DEC had established an organization to distribute and update newest fiches to its field service departments world wide.
As a former field service engineer (FSE) told me: "Every week new fiches arrived, updating our local library was a permanent job. To be honest, fiches for devices not beeing serviced in our area were simply thrown away..."
Several types of documents were include, all color coded in the title strip of a fiche:
- Hardware manuals,
- Software manuals,
- Electronic and mechanical schematics,
- Listings of diagnostics programms,
- Field change orders (FCO's, hardware bug fixes)
- Indexes for hardware options, software and documents.
DEC's use of micro fiches is explained in the "Micro Fiche User Guide", see attachement.
Micro fiches can carry a lot of information on minimal space. A FSE could carry all needed docs in one single "library" box.
Such a box could contain 1000 fiches, with a total of over 100.000 document pages. Today a scanned document page can be saved in about 100K, so such a box is worth 10GB of information. (Remember: In the early 1980's, a 400MB hard disk had a mass of more than 80kg!)
Micro film readers are special forms of slide projectors. In the field, FSE's had mobile readers. They look a bit like a modern notebook and could be operated with line power or with a 12V car battery. And even a fiche box fits inside.
Access to documents on these readers was very quick: Fetching a fiche out of the library box was as easy as locating it in the big directory trees on your hard disk.
The fiche was inserted then between two glass plates. You'd browse the pages by moving the fiche carrier in two dimensions. Page access is indeed much faster than browsing PDFs wich your "Acrobat" or "Foxit" PDF reader!
Major drawbacks of micro fiches were: you had to distribute them physical, you could not easily print, you only could distribute black&white documents, you could not search for text, you couldn't copy ...
So with appearance of Internet for every body, fast notebooks and big hard disks, micro fiches died out.