PowerPoint 5.1 I/O
5.2 I/O
5.3
5.4 I/O
5.5
5.6
5.1 I/O
5.1.1 I/O
1I/O

1)

2)

3)

4)

(2)
(3) ()
2

5-1
1)
2)
5.1.2
1
1)

2)

3)

4)
5)
6)
2
1)
2)

3) I/O
5-2
5.1.3 I/O

I/OI/O(I/O)I/OI/O: I/OCPU

2
5-3ABCDE…N…AA1A2A3…BB1B2B3…()A1B1C1D1 …A2B2C2D2 … A3B3C3D3 …

5-3
2) (Block Selector Channel)
3) (Block Multiplexor Channel)
3“”

5-4 I/O
“”5-512341121“”

5-5 I/O
5.1.4

5-6 I/O
1ISAEISA
2) EISA(Extended ISA)

2(Local Bus)

1) VESA(Video Electronic Standard Association)
VESA32132 Mb/s2090486VESA24Pentium

2) PCI(Peripheral Component Interface)

5.2 I/O
5.2.1 I/O

5-7 I/O
5.2.2 I/O

I/OCPUCPUI/OCPUCPUI/O100 ms0.1 msI/OCPU99.9 ms—CPU99.9 ms0.1 msCPU

5.2.3 (DMA)I/O
(1) CPUI/O
(2)
2DMA

5-8 DMA
DMA
(2) (MAR) 
(3) (DR)
3DMA

DMA()(DR)()MARMAR1DC11DC0()DMA5-9DMA

5-9 DMA
5.2.4 I/O
1I/O
I/ODMACPU()()CPUI/OCPU()I/OI/OI/OCPUI/O
2
(2) ()()
(3) ()
(5) RR=0R=1

81389280103411731405830588960430056500

5.3.1

(2) CPUCPU5-10(a)CPU9.6 Kb/sCPU9.6 Kb/s100 μsCPUCPU100 μs8()5-10(b)CPU1/885-10(c)CPU800 μs

5-10
5.3.2

5-11
2(Double Buffer)

5-12
5-13
5.3.3
1

5-14
2

(2) ReleasebufCReleasebufC()CRReleasebufG

3
(1) NextiNextgRReleasebuf

(2) NextgNextiReleasebufI/O

5.3.4
1
:
()


:
(3) outqF(outq)L(outq)

2GetbufPutbuf
(1) Addbuf(typenumber)numberBtype
MS(type)RS(type)GetbufPutbuf
Procedure Getbuf(type)
3
5-15
(1) Getbuf(emq)emqhinPutbuf(inqhin)inq
(2) Getbuf(inq)inq(sin)Putbuf(emqsin)emq

(3) Getbuf(emq)emqhoutPutbuf(outqhout)outq
(4) Getbuf(outq)soutPutbuf(emqsout)

5.4 I/O

I/O I/O
I/O
1)
OSI/O
2)
3)
4)

5)

6) I/O
I/OI/OI/OI/OI/O

I/OI/O 5-16(I/O)
(1) I/O

(2)
(3) I/O
(4) CPU

5-16 I/O
5.4.2
1()
2CPU
5-17
3
4

5

I/OI/OI/O4I/OUNIX45-18

5-18
5.4.3
1
I/O
(2) I/OI/O
(3) I/OI/OI/O

(4)
2
(2) I/OI/O
(3) ()
3
:
(3) I/OI/OI/ODMA
(5)
(6) MMUDMA

4
“”



2) I/O

3)

4)
5)

6) I/O
I/OI/OI/O/()

5.4.4
1

1)
2) I/O

2
(1) :


(2) ()readwrite

3
1)
5-19
2) LUT

5.4.5 I/O
CCwriteI/OCC
5.5.1
1(DCT)
5-20
typedeviceid
(2) /“1”“1”

(3) DCT
(4)

2

5-21 COCTCHCTSDT
5.5.2
:

1

(1)
(2)
(3) ()

2
3

1)

2)

5.5.3
1
1)

2)

2

1)

2)

5.5.4 SPOOLing
1SPOOLing

2SPOOLing
SPOOLing

(2) CPU
(3) SPiSPoI/OSPiCPUSPo

5-22 SPOOLing
3



4SPOOLing

(2) SPOOLingI/O
(3) SPOOLing

5.6
5.6.1
1

5-23
10 GB816()16 383()63


5-24()30600512
(2) 512
5-24
2
1)
2)

3
1) Ts
Ts = m ×n +s
mm=0.2m≤0.12 ms530 ms

2) Tr
300 r/min720015 000 r/min15 000 r/min4 msTr2 ms 300 r/min600 r/minTr50100 ms

3) Tt
Tt/b:

/20 ms10 MB/s10 KB21 ms100 KB30 ms1050%80 MB/s()

5.6.2
5-259I/OFCFS()55.3FCFSI/O

5-25 FCFS
2(SSTFShortest Seek Time First)
5-26SSTF95-255-26SSTFFCFSSSTFFCFS

5-26 SSTF
3(SCAN)
2) SCAN

5-27 SCAN
4(CSCAN)

CSCAN2TT + SmaxTSmax()5-28CSCAN9

5-28 CSCAN
5NStepSCANFSCAN
1) NStepSCAN

2) FSCAN
5.6.3
1

2


3
1)

2)

3)
LRULRULRU(LRU)
4

UNIX(update)SYNCSYNC30 s30 sMS-DOS: “”(write-through cache)MS-DOS

5.6.4 I/O
1(Read-ahead)

2

3
()4
4

5.6.5
1
……NN1NI/ON-15-29

5-29
2RAID

(2) RAID 184 4 50%
(3) RAID 3766/7RAID 3

(4) RAID 5/(Spiral)RAID 5I/O
(5) RAID 6RAID 7RAIDRAID 6RAID 3RAID 5RAID 7RAID 6

3RAID

(2) I/OI/ON-1(N)I/O
(3) /RAID1/31/31/N50%
rN
b
T

CPU