A-7 Worksheets - Input Devices
Keyboards:
# of Keys ___________
Key Feel ___ "Click" ___ "Soft Touch"
Programmability ___ No ___ Yes
Plug Size (the part that plugs into the computer) ___ Normal ___ Mini Din
Are there Win95 quick keys? ___ Yes ___ No
Are there Internet shortcut keys? ___ Yes ___ No
Special Features ___________________________________________________________
__________________________________________________________
__________________________________________________________
I, personally, hate the "natural" style of keyboard... and can
ONLY use it if I am sitting down properly. Which, when you are turning to
multiple computers & key boards, the "straight" lined keys seem to
work the best for me. I have noticed that many typists prefer the natural
(curved) boards, and can actually type 10 to 30 words per minute faster!
Mouse:
# of Buttons ___ 2 ___ 3
Wheel or Stick? ___ Yes ___ No
Interface Type ___ Serial ___ Bus ___ Mouse port (PS/2)
MS Compatible ___ No ___ Yes
Logitech ___ Yes ___ No
Special Features ___________________________________________________________
__________________________________________________________
__________________________________________________________
I, personally, prefer the Logitech wheel mouse,
with the Microsoft wheel mouse second, and the A4Tech 4D double wheel and the
Mitsumi stick being tied for third place. There is a difference in mice, and
spending the money on a good one will save you in the long run! Also, get
a mouse cleaning kit, which will help your mouse work better and last
longer also! Curtis makes a good kit for about $10-20 (US).
Options:
Scanner (SCSI or Parallel) ___
No ___ Yes - Interface ___ Included ___ Needed
Digitizer (SCSI or Serial) ___
No ___ Yes - Interface ___ Included ___ Needed
Light Pen (Serial or USB)
___ No ___ Yes - Interface ___ Included ___ Needed
Camera (Serial or USB) ___
No ___ Yes - Interface ___ Included ___ Needed
Other Options: ___________________________________________________________
__________________________________________________________
__________________________________________________________
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The type of interface is also important. There are generally only
five choices. Proprietary (less common today), Serial, Parallel, SCSI, or USB. You need to be somewhat careful. Each of the
interfaces have pluses and minuses, and different setup problems.
| Proprietary - This is the strangest and most difficult. It could be a mutated
version of a serial, IDE, or SCSI controller. These proprietary controllers are usually
built into sound cards to control CD ROM drives, aka "Multimedia Kits;" or
bundled with tape drives, aka "high speed tape backup controllers." They seldom
exist elsewhere in the "real world" of computing, and have been mostly
discontinued since 1996.
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| Serial - Generally your mouse is either on Com1 (IRQ 4) or the PS/2 port (IRQ
12) and a modem often over-rides Com2 (IRQ 3)... adding additional Com ports is possible,
yet challenging. So be careful here. Many of the UPS (Un-interruptible Power Supplies, aka
"battery backups") have a serial cable for automated power management. I don't
suggest hooking up a UPS to the serial port, except for Network servers, and
advanced users. Serial ports are most commonly used for older mice, digital
cameras, fax modem cards, bar code scanners, and even invoice printers (like
UPS - the shipping company uses). Either way, no mater your planned use, you want UART 16550 ports!
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| Parallel - Until 1995/96 this was not a very fast or acceptable connection
method - except for printers (which were also fairly slow until about the
same time). However, today with faster motherboards and high speed printer ports
(ECP
= Enhanced Capabilities Port, and EPP = Enhanced Parallel Port) data can now travel faster
and better. Just a few years ago 200,000 bytes per second was the maximum speed with a
standard bi-directional port. Today, speeds over 1,000,000 bytes per second are possible
with the Enhanced ports. Parallel scanners, Hard drives, Tape drives, CD ROMS, Zip drives,
and a few other devices are now feasible to run through the printer port without any major
delays or problems. It is also possible to "chain" multiple
devices (up to 7) in a row off the parallel port... I only such two or three
devices.
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| SCSI - This is a special card in your computer (possibly
built-in on very high-end motherboards, which I DO NOT recommend). There are three
"common" types: 1, 2, and 3. The advantage of SCSI-1 & 2 devices is that you
can run up to 7 devices off ONE controller, and it was specifically
designed for multi-tasking, networks, and huge files.
Commonly used for high-end scanners and external drives (hard drives, Zip,
Jaz, SysJet, SyQuest, Exabyte, cd, cdr, cdrw, tape, etc.).
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| SCSI-1 is usually 8bit, and has a max speed of 5MB per second transfer with
optimum configuration. A SCSI-1 can only run SCSI-1 devices. Still used in
many external drives, especially the parallel CD's and hard drive support
(via "Shuttle Technology").
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| SCSI-2 is 16 bit minimum, sometimes 32 bit VLB (Vesa Local Bus) or PCI. The
SCSI-2 cards have a maximum transfer rate of 20MB per second, with 10 to 15MB average. A
SCSI-2 controller can effectively run SCSI-1 devices without problem.
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| SCSI-3 is a little different -
is usually 32 bit. It is 68 pins, capable of 30MB per second
sustained transfer PER DEVICE, and up to 15 devices on one controller.
Rumor has it that the maximum speed that can be attained is 80MB per
second! This is the latest, greatest,
fastest, and most expensive type of storage device (controller &
drive) currently on the market.
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| USB - Hailed as the latest and greatest
type of ports available, with up to 63
devices supposedly being able to be daisy chained off EACH port! Wow! Speeds
in the 12MB per second range, (yes, 12,000,000
bytes) and automatic driver installation via
firmware. Pretty incredible, huh?!?
| Well, the USB port was first
introduced around 1993, but didn't really become popular until about 1997
when mice, printers, and monitors actually started to try and use the port.
The theory is incredible, but the application of these devices are sometimes
a challenge.
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| Also, not many companies have built their USB devices to daisy chain,
as they don't want the hassle and responsibility of an end-user thinking the
new device made the old device no longer work. So, out comes the USB
"hub" - generally in a 4 - 8- or 16 port version (although the USB
ports are supposedly able to deal with 63 devices each).
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| Printers, Joysticks, Cameras,
Video devices, Microscopes, and removable disk drives are the latest wave of
things trying to take advantage of the speed and power of the USB
ports.
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| Running an USB mouse on a desk top system is a breeze, running
one on a laptop (or notebook computer) and expecting it to operate in plug-N-play
mode is unlikely (and sporadic at best, especially compared to the PS/2
mice).
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The IRQ (Computer Address - Interrupt request) settings are also extremely important.
An IBM/Microsoft based computer ONLY have 15 IRQs to choose from, and normally about 10 to
12 are used by the motherboard, CPU, internal bus, video card, keyboard, bios, I/O ports,
etc. USB ports have the ability to SHARE IRQ's without conflict or problems (alledgedly).
Copyright 1998 T.E. Mercer, all rights reserved. This page was last updated 16 April 2000
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