1964_IMPORT_AND_EXPORT_(STRATEGIC_COMMODITIES)_REGULATIONS — Page 116

G 116 CAP. 60]

Import and Export (Strategic Commodities) Regulations

[1988 Ed.

[Subsidiary]

(1) The input/output control unit ‘transfer rate' (R1); or

(ii) The sum of the individual 'transfer rates' of all independent seek mechanisms (R).

Thus: Rtd = min (Re; SUM Rts);

(2) Of an input/output control unit (R+c):

(i) With rotational position sensing (rps), is the product of:

(a) The number of independent read/write channels (C); and

(b) The greatest "maximum bit transfer rate" (Rismaxmax) of all independent seek mechanisms; or

(ii) Without rotational position sensing (rps) is two-thirds of this product.

Thus:

Rtc = C. Rismaxmax (with rps); or

2/3 C. Rismaxmax (without rps);

(3) Of an independent seek mechanism (R):

The product of:

(i) The "maximum bit transfer rate" (Rismax); and (ii) The rotational period (tr);

Divided by the sum of:

(i) The rotational period (tr);

(ii) The 'minimum seek time" (tsmin); and

(iii) The 'latency time' (tl);

Thus: Rts = Rismax × tr / (tr + tsmin + tl)

'minimum seek time' (tsmin)

(1) For fixed head devices, it is zero; or

(2) For moving head or moving media devices, the rated time to move from one track to an adjacent track.

'latency time' (tl)

The rotational period divided by twice the number of independent read/write heads per track.

(b) of the input/output control unit-magnetic tape drive combinations (Rttot): The sum of the individual 'transfer rates' of all input/output control unit-magnetic tape drive combinations (R1) provided with the system which can be sustained simultaneously assuming the configuration of equipment which would maximize this sum of rates.

Thus: Rttot = SUM R1

"Transfer rate'

Of an input/output/control unit-cartridge-type streamer or magnetic tape drive combination (R):

The product of:

(1) The number of independent read/write channels (C); and

(2) The greatest maximum bit transfer rate" (Ritmaxmax) of all tape drives.

Thus: R1 = C. Ritmaxmax

(c) of the input/output or communication control unit-directly connected data channel combinations:

The sum of the individual "transfer rates" of all data channels provided with the system which can be sustained simultaneously assuming the configuration of equipment which would maximize this sum of rates.

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