Introduction to Machine Structure- IBM 360 and 370

1. Sanjivani Rural Education Society’s
Sanjivani College of Engineering, Kopargaon-423 603
(An Autonomous Insttute, Affiated to Savitribai Phufe Pune University, Pune)
NACC ‘A’ Grade Accredited, ISO 9001:2015 Certified
Department of Computer Engineering
(NBA Accredited)
Dr. S. N. Gunjal
Assistant Professor
E-mail : gunjasanjay@sanjivani.org.in
Contact No: 91301 91301 Ext :145, 9503916876
Course- System Programming and Operating System
(CO312)
Introduction to Machine Structure- IBM 360 and 370
Dr. S.N Gunjal
Dr. S.N Gunjal

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1. Memory
The basic unit of memory in 360 and 370 is a byte (eight bits of information).
It means, each addressable position in memory can contain a byte of information.
There are facilities to operate on contiguous bytes in basic unit.
Machine Structure- IBM 360 and 370
Byte 1 8
Half word 2 16
Word 4 32
Double word 8 64

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2. Register

There are a total of 16 general purpose registers of 32 bits each.

In addition there are 4 floating point register of 64 bits each.

It also has a 64 bits program status word (PSW) that contains the value of the
location counter, protection information and interrupt status.

Let us take an instruction A 1,901(2,15).
A(opcode)1(operand in register 1),901(offset) (2(index register),15(base register))
Machine Structure- IBM 360 and 370

5. 1. Addressing using base register.

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2. Addressing using base register.
Machine Structure- IBM 360 and 370

7. 3. Data format

8. 3. Data format

9. 4.Instruction formats

10. Instruction Set

12. Types of Instruction

16. Example of SS instruction

17. 15/06/20 DEPARTMENT OF COMPUTER ENGINEERING, Sanjivani COE, Kopargaon
Text books & Reference Books(R) :
Text Books(T):
John Donovan, “System Programming”, McGraw Hill, ISBN 978-0--07-460482-3.

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Thank You
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