IBM 7302
Encyclopedia
The IBM 7302 Core Storage unit was designed in 1957-1958 for the IBM 7030
(Stretch). The IBM 7030 could use from one to sixteen IBM 7302s (typically six); either individually or in interleaved groups of two or four. The IBM 7090
also used one IBM 7302. The IBM 7094 used one IBM 7302A. The IBM 7094 II used one IBM 7302, but it was a new model unique to the IBM 7094 II. The IBM 7080
also used one decimal model IBM 7302 with a different core stack than used in the binary models.
Binary models of the IBM 7302:
Decimal models of the IBM 7302:
The core memory in the IBM 7302 was heated/cooled to stabilize its operating characteristics. Early units immersed the core stack in heated/cooled oil, later units called the IBM 7302A, blew heated/cooled air through the core stack. The use of smaller cores in the IBM 7302A allowed the cycle time to be reduced to 2.0µs for the IBM 7094. The use of even smaller cores in the IBM 7302 Model 3 allowed the cycle time to be reduced to 1.4µs for the IBM 7094 II.
IBM 7030
The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. The first one was delivered to Los Alamos National Laboratory in 1961....
(Stretch). The IBM 7030 could use from one to sixteen IBM 7302s (typically six); either individually or in interleaved groups of two or four. The IBM 7090
IBM 7090
The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
also used one IBM 7302. The IBM 7094 used one IBM 7302A. The IBM 7094 II used one IBM 7302, but it was a new model unique to the IBM 7094 II. The IBM 7080
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....
also used one decimal model IBM 7302 with a different core stack than used in the binary models.
Binary models of the IBM 7302:
- 1. 16,384 – 72-bit words w/ 2.18µs cycle time (IBM 7302A 2.0µs cycle time)
- The IBM 7030 used this as 16,384 – 64-bit words and an 8-bit ECC. Interleaving of units could reduce effective cycle time to 1.09µs (two unit groups) or 0.545µs (four unit groups).
- The IBM 7090 used this as 32,768 – 36-bit words.
- The IBM 7094 used this as 32,768 – 36-bit words. Instructions were fetched in 72-bit word pairs, reducing effective instruction fetch time to 1.0µs.
- 2. 8,192 – 72-bit words w/ 2.18µs cycle time
- The IBM 7030 used this as 8,192 – 64-bit words and an 8-bit ECC. Interleaving of units could reduce effective cycle time to 1.09µs (two unit groups) or 0.545µs (four unit groups).
- 3. 32,768 – 36-bit words w/ 1.4µs cycle time and Even/Odd word overlapped access.
- The IBM 7094 II used this as 32,768 – 36-bit words. Because the Even 36-bit word and Odd 36-bit word were independent in this model their accesses could overlap, which could reduce effective cycle time to 0.7µs.
Decimal models of the IBM 7302:
- 1. 160,000 – 7-bit characters w/ 2.18µs cycle time
- The IBM 7080 used this as 160,000 – 7-bit characters; CBA8421.
- 2. 80,000 – 7-bit characters w/ 2.18µs cycle time
- The IBM 7080 used this as 80,000 – 7-bit characters; CBA8421.
The core memory in the IBM 7302 was heated/cooled to stabilize its operating characteristics. Early units immersed the core stack in heated/cooled oil, later units called the IBM 7302A, blew heated/cooled air through the core stack. The use of smaller cores in the IBM 7302A allowed the cycle time to be reduced to 2.0µs for the IBM 7094. The use of even smaller cores in the IBM 7302 Model 3 allowed the cycle time to be reduced to 1.4µs for the IBM 7094 II.