Contact us Heritage collections Image license terms
HOME ACL Associates Technology Literature Applications Society Software revisited
Further reading □ Overview □ About Ferranti □ Brochure □ Architecture □ Architecture □ 1-Level Storage □ Words □ Instructions □ Order Code □ Animated □ Hardware □ Fixed Store □ Supervisor □ Overview □ Scheduler □ Core Memory □ Atlas Card □ Atlas Console □ Console Details □ Chilton □ Chilton Atlas □ Downstairs □ Manchester □ Manchester Atlas □ London □ London Atlas □ London Software □ Atlas II □ Atlas 2 Brochure □ Titan Autocode □ Cambridge Atlas □ Closure □ Atlas Closure
ACD C&A INF CCD CISD Archives Contact us Heritage archives Image license terms

Search

   
⟶ ACL ⟶ Technology ⟶ ATLAS
⟶ ACL ⟶ Technology ⟶ ATLAS
ACL ACD C&A INF CCD CISD Archives
Further reading ⇓

□ Overview □ About Ferranti □ Brochure
Architecture
□ Architecture □ 1-Level Storage □ Words □ Instructions □ Order Code □ Animated
Hardware
□ Fixed Store □ Supervisor □ Overview □ Scheduler □ Core Memory □ Atlas Card □ Atlas Console □ Console Details
Chilton
□ Chilton Atlas □ Downstairs
Manchester
□ Manchester Atlas
London
□ London Atlas □ London Software
Atlas II
□ Atlas 2 Brochure □ Titan Autocode □ Cambridge Atlas
Closure
□ Atlas Closure

Atlas Architecture

The Architecture

The main parts of Atlas 1 consist of:-

  1. The control unit: responsible for pipelined instruction decoding and initiating the relevant action
  2. Floating Point Arithmetic Unit: for all floating point arithmetic operations
  3. Integer Arithmetic Unit: for all integer and character operations
  4. The Supervisor: schedules the running of jobs and switching as necessary. Atlas was probably the first machine whose control program warranted being called an operating system.
  5. The storage system: programs could address a million words of store which either resided in main memory or on drums. The Supervisor made this appear like a 1-level storage system by paging blocks of information in and out of main store.
  6. Input and output devices: the main backing store was either 1 inch Ampex pre-formatted tape or a fixed disc. Compatible IBM 7-track magnetic tape decks were also available.

The following diagram shows the component parts of Atlas 1:-

INPUT V-STORE OUTPUT FIXED STORE SUPERVISOR AND SUPERVISOR WORKING SPACE SYSTEM MAGNETIC TAPE PRIVATE STORES CONTROL B-REGISTERS B-REGISTERS ARITHMETIC UNIT ACCUMULATOR ACCUMULATOR ARITHMETIC UNIT MAGNETIC DRUMS CORE STORE MAGNETIC Tape GENERAL STORES
⇑ Top of page
© Chilton Computing and UKRI Science and Technology Facilities Council webmaster@chilton-computing.org.uk
Our thanks to UKRI Science and Technology Facilities Council for hosting this site