As of Feb, 2006 there are over 8818 documents containing
over 830,000 pages in the archive.
Would you like to help bitsavers?
We're looking for documentation and software for
minicomputers and mainframes, from the 50's to the 80's.
email contrib at
bitsavers dot org if you can help.
Help Us Save What Bits Still Exist
Work on the bitsavers project has been going on now for over
five years, and it is appears that very little software for
minicomputers and mainframes has survived in machine-readable
form from the mid-seventies and earlier. If you know of surviving
software on 1/2" tape, paper tape, cards, DECtape, etc. from
users groups or computer manufacturers, please contact us. Equipment
is available to recover these bits, and in some cases can be brought
on-site.
Active Mirrors
Please use these, as bandwidth to bitsavers is VERY limited:
bitsavers.trailing-edge.com (all)
bitsavers.vt100.net (pdf)
computer-refuge.org/bitsavers (pdf)
zerkalo.curie.fr./mirrors/www.bitsavers.org/pdf
Archive Indexing
Files are indexed in three files at the top level of the heirarchy:
IndexByDate.txt is updated each time an indexed document is added to the archive.
Whatsnew.txt contains a name of the document, with a short description sorted by date of addition.
Index.txt contains the indexed contents of the archive, sorted by vendor.
The PDF Document Format
Documents here are kept in a minimal subset of PDF format, just using it as a
container for lossless Group 4 fax compression (ITU-T recommendation T.6) images.
Contributions are normally post-processed by tools to put them in exactly this format,
so that all of the documents here are the same and can be burst at some point in the
future when OCR technology is mature enough to do a good job of recognition.
Most documents are scanned using a Ricoh IS520 30ppm duplex production scanner.
Post-processing is done using Lemkesoft's Graphic Converter
TIFF to PDF conversion is done using Eric Smith's tumble
The preferred form for any contributed text scan is as a collection of lossless
Group 4 fax compression (ITU-T recommendation T.6) images saved as TIFF
files with a minium scan resolution of 400 dpi.
Lower scan resolutions produce noticable artifacts if a page needs to be
straightened in post-processing.
Lossy compression formats, such as JPEG, should NEVER be used to save pages
of text, since the compression format destroys edge resolution and contrast
would make it difficult to OCR in the future.
Bitsavers' Toolchest
Tools used at Bitsavers for scanning and media recovery.
Snapshots/Mirrors
Jul 2004 shapshot of pdp-11.trailing-edge.com
Jan 2005 shapshot of simh.trailing-edge.com
Links