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Browse Prior Art Database

Security Mechanism

IP.com Disclosure Number: IPCOM000090596D
Original Publication Date: 1969-May-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 3 page(s) / 34K

Publishing Venue

IBM

Related People

Franklin, JW: AUTHOR

Abstract

This security system prohibits disruption of I/O volume operation while the I/O device is under program control. The operator is prohibited from opening the access cover and from manipulating the manual controls while the device is under program control. Such I/O device volume can be magnetic tape, paper tape, magnetic disk pack, magnetic strip, etc. When the program no longer requires that the device be under its exclusive control, it issues an Unlock Control order to release the volume and restore manual control. This system obviates the need for a manual lock-and-key system.

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Security Mechanism

This security system prohibits disruption of I/O volume operation while the I/O device is under program control. The operator is prohibited from opening the access cover and from manipulating the manual controls while the device is under program control. Such I/O device volume can be magnetic tape, paper tape, magnetic disk pack, magnetic strip, etc. When the program no longer requires that the device be under its exclusive control, it issues an Unlock Control order to release the volume and restore manual control. This system obviates the need for a manual lock-and-key system.

A Lock Control command, instruction, from the CPU program is not required. The device automatically locks itself and disables its own manual controls when the operator makes the device ready and is enabled while power remains on in the device. The operator first puts the Power switch 1 into the on position which puts trigger 14 in the on state. Trigger 14 is restored to off state only by emergency power-off procedures, not shown, or by putting switch 1 in the off position while the device is Not Ready, Not Enabled, and Not Locked.

Trigger 14 in on state, activates the power-on sequence in Power-on logic 6 and results in the Power On Complete signal if the sequence is completed successfully. Failure to complete the power-on sequence forces trigger 14 to the off state and turns on power-loss warning indicators not shown. However, when power-on sequence is completed successfully, the Power On Complete signal is generated to And 3. Once generated, Power On Complete remains up when power is on in the device.

The next step by the operator in making I/O device ready is to put Enable switch 4 in the on position which puts trigger 9 in the on state. Such activates enabling logic 5 and results in the Enabled signal 12 to And 3. Once generated, signal 12 remains up to And 3 while power is on in the device and while trigger 9 is in the on state. Trigger 9 is restored to the off state only by emergency power off or while power is on in the device only by proper execution of the Unlock Control command.

The output of And 3 is Ready and Enabled signal 10 which remains up while power is on and the device is enabled. Signal 10 activates Lock logic 6 which activates the mechanisms that prohibit access to the I/O volume, not shown, such as doors, windows, covers, etc...