IBM 7080
| Company type | Computer model |
|---|---|
| Industry | Computer hardware |
| Predecessor | IBM 705 |
| Founded | August 1961 |
| Products | Variable word length BCD transistor computer |
The IBM 7080 was a variable word length BCD transistor computer within the IBM 700/7000 series of commercial computers, launched in August 1961 as a successor to the vacuum-tube IBM 705.
With an approximate weight of , the 7080 resolved compatibility challenges encountered by its predecessor, the IBM 7070, which debuted in June 1960. Due to the 7070’s lack of compatibility with the 705, its market acceptance was limited, motivating IBM to create the fully compatible and improved 7080 model.
IBM 705 compatibility modes
To ensure backward compatibility with the IBM 705, the 7080 incorporated two operator panel switches labeled 705 I-II and 40K memory, which determined the startup configuration:
- 705 I mode — supports 20,000 characters (705 I-II On, 40K memory Off)
- Indirect addressing not enabled
- Communication channels disabled
- 705 II mode — supports 40,000 characters (705 I-II On, 40K memory On)
- Indirect addressing not enabled
- Communication channels disabled
- 705 III mode — supports 40,000 characters (705 I-II Off, 40K memory On)
- Indirect addressing enabled
- Communication channels enabled
- 705 III mode — supports 80,000 characters (705 I-II Off, 40K memory Off)
- Indirect addressing enabled
- Communication channels enabled
From any of these 705 startup modes, software could transition the system into full 7080 mode:
- 7080 mode — supports 160,000 characters
- Indirect addressing disabled
- Communication channels enabled
All operational modes ran at the complete processing speed of the 7080.
The architecture consisted of several components: IBM 7305 Central Storage and I/O Control unit, IBM 7102 Arithmetic and Logical unit, IBM 7302 Core Storage unit, IBM 7153 Console Control unit, and IBM 7804 Power unit. The IBM 7622 Signal Control unit facilitated connectivity with first-generation peripherals such as punched card input/output devices including the IBM 7502 card reader, line printers, and IBM 727 magnetic tape drives on this transistor-based platform. Additionally, second-generation IBM 729 magnetic tape drives interfaced through the IBM 7621 Tape Control unit.