Information Technology Reference
In-Depth Information
Over the past years, the PCI has rapidly moved up the table and takes away the top position
from the ISA bus, and as it does everything well, and beats the ISA bus, for its ease of con-
figuration. Its only problem is that it costs a bit more than the ISA bus, but it's worth it. The
one to watch for is the USB bus. It has came straight into the forth position, and is sure to
rise further as more applications use it, and as it bit rate increases. Busses such as the key-
board, joypad and PS/2 mouse port are not included as they are too specific to a single ap-
plication (but they wouldn't do that well, as they are very slow, and can cause configuration
problems). A special mention should go the Ethernet bus system. It is one of the oldest of the
busses given here, but has withstood a lot of pressure from other busses that would like to
take control of the networking applications, but it has beaten of all of them. Its main strength
is its cheapness, and it general usage. In networking, more any other application area, stan-
dardness counts more than virtually anything else. If a company were to adopt a new net-
work bus for their network, and within five years that technology was either too expensive to
maintain, or was not even available, it would take a major investment to redesign the net-
work. So, Ethernet wins because it has a virtual monopoly on the connection of computers to
corporate networks. Its shortcomings have been overcome with gradual migration. Its slow-
ness has been overcome with new standard such as 100BASE (100MBps) and 1000BASE
(1Gbps). Its connection and grounding problems have been solved with hubs, twisted-pair
cable and fibre optic cable.
Special mentions should go to RS-232 (the only bus to score three top scores) and the
Parallel Port, who do some things extremely well, but their glory days have passed, and are
hoping for glorious retirement as USB mops-up their main application areas. But, who
knows, will RS-232 and Parallel Port connectors still be standard on the PCs in the year
2010? It's an even money bet at the present.
Usefulness
Availability
Data throughput Cost Configuration Total
=1
PCI
9
9
8
6
9
41
=1
Ethernet (100BASE)
10
9
5
10
7
41
=3
ISA
10
9
5
10
5
39
=3
Ethernet (10BASE)
10
9
3
10
7
39
=5
IDE
5
9
6
9
8
37
=5
USB
10
7
4
8
8
37
7
RS-232
10
10
2
10
3
35
8
Parallel port (ECP/EPP)
8
8
5
8
4
33
=9
Parallel port
7
8
3
8
5
31
=9
SCSI-I
8
6
5
5
7
31
=9
AGP
5
6
9
3
8
31
12
SCSI-II
8
4
7
4
7
30
13
PC
5
9
3
7
3
27
14
IEEE-488
7
5
3
6
5
26
15
ISDN
3
6
5
2
5
21
=16
Modem
3
9
1
3
4
20
=16
RS-485
4
5
4
3
4
20
=18
Firewire
3
3
7
2
4
19
=18
PCMCIA
4
5
5
1
4
19
=20
Fibre Channel
2
2
8
2
4
18
=20
MCA
4
1
6
2
5
18
=20
VL
5
1
6
1
5
18
23
EISA
1
1
3
2
5
12
Relegation zone
