Burroughs B700 Family 


Burroughs B700

The original basic B700 was made up of three units - a console, a processor cabinet and a disk drive cabinet.

The console was basically an "empty" Burroughs L4000 - all of the computing parts had just been removed.  The keyboard was the Series L mechanical unit, with an alphanumeric keyboard, a numeric keyboard and 24 function keys.  The wide-carriage inbuilt printer had a split platen, with the narrower section of the platen to the left (for printing the systems log) and the wider part to the right (for printing reports,etc).  The console was generally fitted with a stationery pin-feed mechanism.  The printer was a 20 character-per-second golfball printer, which only printed in upper case.

All of the "brains" were in the processor cabinet - the size of a four-drawer filing cabinet, coloured off-white with a black-glass front (though there were no flashing lights to see through the glass!)  The B700 had its own proprietary operating system, called "SCP" - Systems Control Program.  All programs had a maximum name-length of five characters. SCP included a range of "utilities" - programs designed to help the operator to manage the system and solve problems.  For example, one utility called "SQASH" performed basically the same function as a "disk de-fragmenter" under today's Microsoft Windows.

The disk drive cabinet looked identical to the processor cabinet, except that the glass front was in fact an opening door.  The B700 used disk cartridges.  A disk cartridge was a single platter about 14-inches in diameter, mounted inside a plastic cartridge unit.  To load a disk cartridge into the system you open the disk drive cabinet door, pulled down the handle on a disk drive unit, slide the disk cartridge into the unit, lowered the disk drive handle, and closed the disk drive cabinet door again.  The act of lowering the disk drive handle seated  the disk cartridge onto the drive mechanism, and also opened a large slot in the top of the cartridge so that filtered air could be blown into the cartridge while it was running.  The flow of air was mainly to get rid of any dust particles, which could otherwise cause the disk to "crash".

The standard disk cartridge was "single-density" and could contain up to 2.3 MB of data, and a standard disk drive cabinet had two disk cartridge drives.  If you needed more than 2 x 2.3MB of data capacity, you one two options: you could buy an additional single-density disk drive cabinet to get another 2 x 2.3MB of data, or you could change to a dual-density disk drive cabinet, which could use two removable 4.6MB disk cartridges.  The B700 could manage up to a maximum of 4 disk drive cabinets.

Each disk drive in the cabinet was independent of the other, and the read/write heads on one drive could also move independently of those on the other drive.  Where an application was using more than one file, users could achieve great improvements in performance by putting files on separate drives - sometimes a performance improvement of 40% could be obtained!

One of the most useful additions to a basic B700 was a line printer.

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Last modified:01 January 2017