RCA 301, Руководство программиста

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D Track Select (TS)
General Description
This instruction positions the read/write heads over 1 of 128 tracks. Once initiated the track selection is
performed independently of computer operation.
Format
Operation —D
N —R (First Data Disc File)
— Z (Second Data Disc File)
A Address — Must be zeros (0000).
B Address — B
0
= 0 (zero), will not override a DDF Simultaneous Instruction.
— B
0
= &, will override any DDF Simultaneous Instruction.
— B
1;
B
2
, B
3
designate track address (000 - 127).
Outline of Operation
The contents of the N Register specify the proper Data Disc File. B„ B
2
, B
3
designate the track address which
can range from 000 to 127. All read/write heads within a Data Disc File are positioned concurrently so that 108
zones per module are accessible by the execution of one Track Select instruction.
If this instruction contains a bit in the B
0
2
4
position and the selected Data Disc File is busy in the Simultaneous
Mode, the Simultaneous Instruction being performed will be terminated on the next transfer of data to or from the
file. The new instruction will then be executed in the normal manner.
Final Register Contents
(A)
f
= (A),
(B)
t
- (B)
i
Timing
To initiate selection, 42 nsec.
To perform Track Selection (time in milliseconds) :
Model
Average Maximum
363-2
105
150
363-3
125 160
363-4
145
185
363-5 145
185
XII-3