World Library  
Flag as Inappropriate
Email this Article

Ibm 7080

Article Id: WHEBN0008328134
Reproduction Date:

Title: Ibm 7080  
Author: World Heritage Encyclopedia
Language: English
Subject: IBM 7340, IBM 7302, Input/Output Control System, IBM 700/7000 series, Decimal computer
Collection: 1961 Introductions, Ibm 700/7000 Series, Ibm Transistorized Computers
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Ibm 7080

The IBM 7080 was a variable word length BCD transistor computer in the IBM 700/7000 series commercial architecture line, introduced in August 1961, that provided an upgrade path from the vacuum tube IBM 705 computer.

After the introduction of the IBM 7070, in June 1960, as an upgrade path for both the IBM 650 and IBM 705 computers, IBM realized that it was so incompatible with the 705 that few users of that system wanted to upgrade to the 7070. That prompted the development of the 7080, which was fully compatible with all models of the 705 and added many improvements.

IBM 705 compatibility modes

For backward compatibility with the IBM 705 the machine had two switches on the operator's control panel, 705 I-II and 40K memory, that selected the mode the machine started in.

  • 705 I mode — 20,000 characters (705 I-II On, 40K memory Off)
    • Indirect addressing is disabled
    • Communication channels are disabled
  • 705 II mode — 40,000 characters (705 I-II On, 40K memory On)
    • Indirect addressing is disabled
    • Communication channels are disabled
  • 705 III mode — 40,000 characters (705 I-II Off, 40K memory On)
    • Indirect addressing is enabled
    • Communication channels are enabled
  • 705 III mode — 80,000 characters (705 I-II Off, 40K memory Off)
    • Indirect addressing is enabled
    • Communication channels are enabled

Software can then command the 7080 to enter full 7080 mode from any 705 startup mode.

  • 7080 mode — 160,000 characters
    • Indirect addressing is disabled
    • Communication channels are enabled

Regardless of mode, the 7080 operates at full 7080 speed.

The 7080 system included the IBM 7622 Signal Control, which converted transistor signal levels to levels usable with first generation equipment, allowing all 705 peripherals, including punched card input/output, line printers and the IBM 727 magnetic tape drives, to be used on the 7080. Second generation IBM 729 tape drives connected to the CPU via the IBM 7621 Tape Control.[1]

References

  1. ^ "General Information Manual - 7080 Data Processing System".  

External links

  • IBM 7080 documents on Bitsavers.org
  • Dave Pitts' IBM 7090 support – Includes a cross assembler for the IBM 705/7080
  • BIRTH OF AN UNWANTED IBM COMPUTER Computer History Vignettes By Bob Bemer IBM 7070 connection to IBM 7080
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.