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1. Is DVI-I compatible with DVI-V?
Reader: I own a video card that has a
DVI-I connector. I would like to purchase a
digital LCD monitor. The one I am interested in
has a DVI-V interface. Are the two compatible?
Computer Doctor:
There are three digital video interface standards:
The VESA Plug and Display (P&D)
1.0 specification (Intended to provide an industry
standard digital interface for display devices)
published June 11th, 1997, incorporates a 35-pin
combination digital/analog connector (30 pins for
the digital part, 5 pins for analog). This was
never widely adopted
The VESA Digital Flat Panel (DFP)
1.0 specification (To provide for an interface
between a personal computer and a digital flat
panel monitor) published February 14, 1999,
incorporates an MDR20 (20-pin Mini-D Ribbon)
digital-only video connector. The DFP standard
builds on the prior P&D standard but is digital
only. This had some success in the market, but has
been largely replaced by the DVI specification.
More recently, another group
called the Digital Display Working Group (DDWG)
has authored a specification called the Digital
Visual Interface (DVI) 1.0 specification
(primarily focused at providing a connection
between a computer and its display device),
published April 2nd, 1999. The DVI spec. was
largely authored by Silicon Image and Molex, and
uses many of the prior VESA specifications as a
platform to build on. The DVI 1.0 spec.
incorporates a 29-pin combination digital/analog
connector (24-pins for the digital part, 5 pins
for analog) that is virtually identical to the
VESA P&D connector, except with fewer pins for the
digital portion of the connector. It now appears
that the DVI 1.0 spec. is the one that will win
out in the future (mainly because Intel has backed
it). This means the 29-pin digital/analog
connector will be the one found on most future
video cards and monitors. What Intel wants, Intel
generally gets. <g>
See
http://www.ddwg.org for more info on the DVI
1.0 specification.
The DVI connector has two
varieties: DVI-I (used by your ATI card) supports
both analog and digital displays. This is a
popular feature on video cards because it allows
the port to use an adapter to allow use of a VGA
analog monitor or an analog LCD panel as well as a
digital panel. DVI-V was the early name for what
is also referred to as DVI-D, the digital-only
version of DVI. Viewsonic has a whitepaper with
more information about DVI available at
http://www.viewsonic.com/products/whitepaper.cfm.
My book Upgrading and Repairing PC's: Technician's
Portable Reference, Second Edition, has a
comparison of VGA and the major types of digital
video interface connectors in Chapter 14.
It appears that you should be
able to attach a DVI-V LCD panel to your DVI-I
video card, but I recommend you contact ATI to
verify compatibility.
2. Can the built-in parallel
port be replaced?
Reader: My friend's computer has a
problem with its parallel port. I'm not sure what
to do because the parallel port is built into the
motherboard. Can I replace the port, or is a
motherboard replacement necessary?
Computer Doctor:
It is true that most motherboards have built-in
parallel ports. However these rarely if ever fail.
Even if they did you could disable the on-board
port (via BIOS Setup) and install one on a card.
Most likely the port is configured incorrectly for
the application. Go into the BIOS setup and check
the port configuration. Make sure it is set to
IRQ7, base I/O port address 378h, and in standard
or bi-directional mode. If he is trying to use a
high speed printer or scanner that supports ECP
mode, then set that mode and select DMA channel 1.
You may need to supply the Windows CD-ROM when you
restart to load a new parallel port driver if you
select ECP or ECP/EPP mode.
If you think the port is
defective, it is most likely the cable and not the
port. Replace the cable with what is called an
IEEE 1284 parallal cable. After you check the port
configuration and the cable, if you still think it
is bad, then I recommend running a diagnostic like
the Norton Diagnostics (comes with the Norton
Utilities or SystemWorks) and test the port under
DOS using a wrap plug (also called a loopback
plug). You can get the wrap plug from Symantec,
check the documentation that comes with the Norton
Diagnostics. Another program that can test the
port with a wrap plug is the CheckIt Suite from
SmithMicro; this program includes wrap plugs for
serial and parallel ports.
If after all this, the port is
indeed bad, then you have two choices. One is to
replace the motherboard (recommended), the other
is to disable the port and purchase a parallel
port card. The reason I recommend getting a new
motherboard is that they are cheap ($100 or less),
and this makes a good opportunity to turn a repair
into an upgrade by replacing the existing board
with something newer and better; good
parallel-port cards can cost up to $40. If you
decide to replace the motherboard, make sure the
new one will fit in your current case. If your CPU
and memory are out-of-date, you may need to buy a
new CPU and memory; fortunately the choices today
are very powerful and quite reasonably priced.
3. What's the difference
between I/O addresses and memory addresses?
Reader: I'm confused about the
differences between I/O port addresses and memory
addresses. Some A+ Certification and PC hardware
guides describe I/O port addresses as being actual
memory to which data is sent before going to or
from the port. I know that both are referred to
with hexadecimal addresses, but I could use some
clarification on this topic.
Computer Doctor:
I/O port addresses are
not memory, not even related to memory in
any way. They are bus addresses which are
best thought of as a sort of 2-way radio channel.
In other words, when sending data to an I/O port
address, it essentially flows along the bus,
passing by all adapters, and any "listening" on
that channel (with ports set to that channel
address), will then receive the data. If no cards
are set to that channel, then the data reaches the
end of the bus and is absorbed by the terminating
resistors.
I/O ports are how drivers send
commands and data to devices and vice versa.
Memory has nothing to do with it. The Intel
processor and bus architecture supports 65,536
ports with addresses from 0000h to FFFFh. These
ports are not related in any way to memory
addresses with those same numbers. In other
words, say for example if I send a data byte "ECh"
to memory address 1F7h, it will be sent on
the memory bus to the SIMMs/DIMMs and
stored in the 504th byte of RAM (in beginning of
the first bank of RAM), where it will sit until
something else is written to that location, or the
power is turned off. On the other hand, if I
send same "ECh" byte to I/O Port address 1F7h, it
will be sent not to the SIMMs or DIMMs, but
instead it would be sent along the system bus
(PCI/ISA) and received by the primary IDE drive
(which is set to that port address), which
coincidentally will be accepted as an "Identify
Drive" command, causing the drive to send 512
bytes of data back to the system bus on I/O Port
1F0h, describing and identifying the drive. This
is in fact exactly how your BIOS "auto-detects"
the drive.
Bottom line: Don't believe
everything you see on the A+ test (or other study
guides <g>), they are unfortunately incorrect in
several areas. BTW, my new A+ book, which covers
the 2001 revisions to the A+ Certification exams,
will be published in March 2001. It's called
Upgrading and Repairing PCs: A+ Certification
Study Guide, Second Edition.
4. What settings should I use
for the second parallel port?
Reader: I have been trying to install a
second parallel port on my PC and am having
constant IRQ problems. What settings should I use
for the second parallel port?
Computer Doctor:
Set the 2nd parallel port to IRQ 5, I/O port 278.
Make sure nothing else is using those settings.
Most sound cards like IRQ 5, if you have one there
move it to another free IRQ such as 10.
If you have USB ports and are
using Windows 98, Windows 2000, or Windows Me,
consider using USB peripherals instead; USB will
be the replacement for all standard serial and
parallel ports, and adopting it will solve the IRQ
shortage problem as well. You can add a USB card
to a system with Windows 98, Windows 2000, or
Windows Me and a free PCI slot for about $30.
5. Can two parallel devices
share the same IRQ so long as they're not running
at the same time?
Reader: Recently, I purchased an EPP/ECP
scanner and a parallel port card (IEEE1284 EPP/ECP).
Can I install this card using IRQ7 (the same IRQ
used by LPT1) if I don't use the scanner and my
printer at the same time??? Your book does say
that parallel ports can share an IRQ under DOS,
with the only condition being that both devices
sharing this IRQ cannot operate at the same time.
Am I interpreting this correctly?
Computer Doctor: The problem is that
Windows 95 is a multi-tasking operating system. If
both drivers are active at the same time then you
generally can't share IRQs. Why not set the second
parallel (or Video if you can't disable the video
IRQ) to IRQ 9 or 11? It sounds like those might be
free on your system.
6. I'm having modem and monitor
problems with my new system...
Reader: I have a new system with 2
problems. First, the modem connecting sounds come
through the system speakers as opposed to the
modem speaker and get louder as the speakers are
turned up; my motherboard has integrated audio.
Second, when the monitor goes into sleep mode and
comes out the screen has a hundred or so lines
through it about every third time it goes into
sleep mode. I reinstalled updated video drivers
with no luck.
Computer Doctor: If your modem isn't
connected to the sound card, then this is simply
the way yours was designed. It may be a setting
you can change, I'd look in the modem
documentation and/or ask the manufacturer.
As for the monitor wakeup problem, there are
different ways a video card can signal a monitor
to blank. Try changing the method in your video
card setup. This may also be in your BIOS setup
under the power management settings.
7. How do I make MP3's from my
CDs?
Reader: How do you convert .cda (CD
Audio) files from a compact disc to .mp3 files on
your hard drive?
Computer Doctor: Use a program to convert
the files, such as the free Windows Media Player 7
you can download from Microsoft at
http://windowsupdate.microsoft.com. Also, most
of the software included with CD-RW drives such as
Nero Burning ROM
or Roxio (Adaptec)
Easy CD Creator 5 Platinum Edition
http://www.roxio.com have the ability to
convert CDA to MP3. You can also use WinAmp or
other standalone MP3 player programs to perform
this task, which is often called 'ripping'.
If you are really serious, check out
MP3 Underground, also published by Que for
every bit of information you could possibly want
about MP3s and music!
8. I want to install a new
video card, but I need to support my DVD drive,
what can I do?
Reader: I have a Gateway PII 400MHz and
I just bought a new AGP video card to replace my
old card. When I opened my computer, I noticed
that the video card was connected to my DVD
decoder card. The new AGP card does not connect to
my DVD decoder. I called Gateway and they said
that I need to get a new DVD because it won't work
if it can't be connected to the video card. The
video card vendor tells me that I need to install
a software decoder and that it should work even if
it isn't connected to the video card. Who's right?
Computer Doctor: You will either need a new
DVD (MPEG-2) decoder card such as
http://www.creative.com/pcdvd/products/decoderdxr3,
or a software DVD (MPEG-2) decoder program such as
PowerDVD 3.0
http://www.cyberlink.com.tw or WinDVD 2000
http://www.intervideo.com.
Either the hardware or software decoders will come
with a companion DVD player application. Note that
your 400MHz processor speed is marginal for
software decoders and if you really do watch DVDs
you may find the picture and sound will be jerky
and problematic. Fortunately, you can download
trial versions of the software decoders listed and
test them before purchasing.
9. My PC won't acknowledge my
2nd serial port, can you help?
Reader: My computer doesn't recognize
serial port #2. When I plug in the serial cable
from my camera is says it doesn't exist. I have a
mouse in serial #1. How do I get it to recognize
this port?
Computer Doctor: Enter your BIOS Setup and
make sure that Serial Port #2 is enabled. Note
that whoever built your system may have
intentionally disabled that port to prevent a
conflict with an internal modem. If you have an
internal modem and it is Plug and Play (PnP),
hopefully it will be automatically reconfigured to
avoid any conflicts.
If enabling the port in the BIOS setup doesn't
help, then check for conflicts in the Device
Manager. If the port is listed and recognized,
then the problem may be with your camera, cable,
and/or the camera software.
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