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Disk I/O Support
IOT (I/O Teach)
IOT allows you to change any configurable parameters and attributes of the device. In addition, it allows you to view the controllers available in the system.
IOC (I/O Control)
IOC allows you to send command packets as defined by the particular controller directly. IOC can also be used to examine the resultant device packet after using the IOP command.
BO (Bootstrap Operating System)
BO reads an operating system or control program from the specified device into memory, then transfers control to it.
BH (Bootstrap and Halt)
BH reads an operating system or control program from a specified device into memory, then returns control to 177Bug. It is used as a debugging tool.
Disk I/O via 177Bug System Calls
| All operations that actually access the disk are done directly or |
| indirectly by 177Bug TRAP #15 system calls. (The |
| disk operations provide a convenient way of using these system |
| calls without writing and executing a program). |
| The following system calls allow user programs to perform disk |
| I/O: |
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.DSKRD | Disk read. Use this system call to read blocks from a disk into memory. |
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.DSKWR | Disk write. Use this system call to write blocks from memory onto a |
| disk. |
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B |