Why can't the printer access the LPT1 port? IBM Aptiva 2137-E33 c
S.@discussions.microsoft.com Pat S.
but not in two others. Why do the non-working configs. give the error
“cannot access the port?”
I have used the Windows-95 operating system in computers with four different
motherboards, but have only observed the printer-plus-parallel-port phenomena
I am reporting here on an IBM (International Business Machines), Aptiva
2137-E33 computer with a V58XA-1 motherboard with the identifications
“97114-1N” and “48 38401.01N” and “Made in Taiwan” appearing on the
motherboard. Details for a presumably similar, V58XA motherboard are given
at http://www.uktsupport.co.uk/acer/mb/v58xa.htm. This discussion is limited
to the IBM computer and its motherboard in a Windows-95, OSR2 operating
system with a number of Windows-95 updates that have also been installed.
The amount of Random Access Memory (RAM) was increased to 256 megabytes of
RAM using two sticks of RAM, each with a capacity of 128 megabytes. The
computer's central processing speed is 200 megahertz. The motherboard has a
parallel port mounted right on it with its output as a 25-receptacle
connector located behind the motherboard and on the back of the computer
tower. The 25-pin end of a printer cable was connected to that port; the
other end of that cable was connected to an Epson, Action Printer 4000
(AP-4000), which uses a reliable ribbon for printing. Alternatively a Canon
BJC-2110 printer could be connected to the motherboard parallel port using
its own cable; this printer uses one, three-color, ink cartridge and one,
black, ink cartridge. To make the test prints I discuss here with each
printer I used only black ink.
Early on I performed some printer tests with the cartridge-based Canon
printer, which led me to suspect that there could have been a hardware
problem with the motherboard printer port. Realizing that printing problems
could also include cartridge problems, I eventually relied heavily on the
highly reliable Epson, ribbon-based printer for printing tests. In
attempting to make test prints the most common type of error I encountered
was “cannot access the port.” Someone suggested I try or obtain a
parallel-port card to use instead of the motherboard parallel port.
Eventually I obtained an Industry Standards Architecture (ISA) parallel-port
card with excellent printed instructions for jumper wiring settings, kindly
supplied by a neighbor. That card included two communication (COM) ports,
which I jumpered to disable them, and the parallel port which I jumpered to
use Interrupt Request (IRQ) 7 and either of the port names LPT1 or separately
LPT2.
A short-term goal was to have no IRQ or memory-address conflicts among the
devices in the computer. I found that I could see a list of the IRQs for the
installed devices by clicking “Start,” “Settings,” “Control Panel,” and in
“Device Manager” by left-mouse-clicking on “Computer,” clicking
“Properties,” and on the “View Resources” tab having the radio button beside
“Interrupt Request (IRQ)” selected. Device conflicts were apparent either by
immediate information from within Device Manager or by messages which
appeared after turning on the computer before entering Windows 95. In spite
of the computer manual informing me that the motherboard parallel port has or
should have IRQ 7, the modem has or should have IRQ 4, and an audio device
has or should have IRQ 5, eventually I found that the following IRQ settings
could be achieved without any IRQ or memory-address conflicts:
Device IRQ
Audio devices 4 and 9
Modem 10
Motherboard parallel port 5
Added, card parallel port 7
. This configuration was achieved with difficulty by a combination of
forcing one or more IRQ setting(s) and letting the Configuration Manager set
other IRQ settings.
With these IRQ settings I found two configurations which were successful in
printing test pages using the Epson, ribbon-based printer:
Successful configuration 1a:
i) Parallel-port card jumpered for the port name LPT1
ii) In “Device Manager” under “Ports,” motherboard port listed as “Printer
Port (LPT2)”, parallel-port card listed as “Printer Port (LPT1)”
iii) In “Printers” double-clicking on the “Epson AP-4000” printer icon,
selecting the ”Details” tab, and having “LPT2: Printer Port” selected
iv) Epson AP-4000 printer cabled to the motherboard parallel port on the
back of the computer tower
v) In “Printers” double-clicking on the “Epson AP-4000” printer icon and on
the “General” tab clicking “Print Test Page”
So in this configuration the successful printing was performed through the
motherboard parallel port, which indicated that the motherboard parallel-port
hardware must have been okay, at least in this configuration.
Successful configuration 2a:
i) Parallel-port card jumpered for the port name LPT2
ii) In “Device Manager” under “Ports,” motherboard port listed as “Printer
Port (LPT1)”, parallel-port card listed as “Printer Port (LPT2)”
iii) In “Printers” double-clicking on the “Epson AP-4000” printer icon,
selecting the ”Details” tab, and having “LPT2: Printer Port” selected
iv) Epson AP-4000 printer cabled to the parallel-port card output
v) In “Printers” double-clicking on the “Epson AP-4000” printer icon and on
the “General” tab clicking “Print Test Page”
So in this configuration the successful printing was performed through the
parallel port on the added, parallel-port card, at least in this
configuration.
Note the interesting result that the successful printings were only
performed with the port name LPT2, in the first case in which it was the
motherboard parallel port and in the second case in which it was the added
card's parallel port! For each of the two, successful configurations there
were also two, corresponding failed configurations, which I would have
expected to work. In each case testing them involved making two changes away
from the successful configurations: A) in software in “Printers”
double-clicking on the “Epson AP-4000” printer icon, selecting the ”Details”
tab, and replacing “LPT2: Printer Port” with “LPT1: Printer Port;” and B) in
hardware switching the 25-pin port end of the printer cable from the port
labeled LPT2 to the port labeled LPT1, i.e., from the motherboard to the card
parallel port for configurarion 1b and from the card to the motherboard
parallel port for configuration 2b:
Failed configuration 1b:
i) Parallel-port card jumpered for the parallel port name LPT1
ii) In “Device Manager” under “Ports,” motherboard port listed as “Printer
Port (LPT2)”, parallel-port card listed as “Printer Port (LPT1)”
iii) In “Printers” double-clicking on the “Epson AP-4000” printer icon,
selecting the ”Details” tab, and having “LPT1: Printer Port” selected
iv) Epson AP-4000 printer cabled to the parallel port output on the
parallel-port card
v) In “Printers” double-clicking on the “Epson AP-4000” printer icon and on
the “General” tab clicking “Print Test Page”
The error message contained “cannot access the port.” So in this
configuration printing failed through the parallel port in the added,
parallel-port card.
Failed configuration 2b:
i) Parallel-port card jumpered for the port name LPT2
ii) In “Device Manager” under “Ports” motherboard port listed as “Printer
Port (LPT1)”, parallel-port card listed as “Printer Port (LPT2)”
iii) In “Printers” double-clicking on the “Epson AP-4000” printer icon,
selecting the ”Details” tab, and having “LPT1: Printer Port” selected
iv) Epson AP-4000 printer cabled to the motherboard parallel port on the
back of the computer tower
v) In “Printers” double-clicking on the “Epson AP-4000” printer icon and on
the “General” tab clicking “Print Test Page”
The error message contained “cannot access the port.” So in this
configuration printing failed through the motherboard parallel port.
It at least at first appeared that for configuration 1a the parallel-port
card was not involved in the successful printing. So I removed the
parallel-port card from the computer and “Printer Port (LPT1)” from “Device
Manager,” only to find that after restarting Windows 95 I presume that the
Configuration Manager
(http://www.microsoft.com/technet/archive/win95/rk31_arc.mspx?mfr=true) had
reassigned the motherboard parallel port from LPT2 to LPT1, as well as
changed the IRQ settings for some devices. In “Printers” I double-clicked on
the “Epson AP-4000” printer icon, selected the ”Details” tab, and selected
“LPT1: Printer Port.” Then on attempting to print from LPT1 I obtained the
usual error “cannot access the port.”
Although I usually had the Epson AP-4000 printer set as the default printer
during the above tests, I don't think that was important because in
“Printers” double-clicking on the “Epson AP-4000” printer icon and on the
“General” tab clicking “Print Test Page” should always involve dealing with
the correct printer in making the test print. Once I had successful printing
using the Epson, ribbon-based printer in configuration 2a, I removed the
Epson printer cable from the parallel-port card parallel-port output,
installed the Canon-printer software, installed the Canon printer cable to
the same parallel-port card, and found that printing using the Canon printer
failed. But after purchasing and installing a new, black-ink cartridge in
the Canon printer, test printing using the Canon printer worked, too.
Summary and the question
So recently I only had successful printings using the IBM computer and Epson
printer when I had the hardware and software for two parallel ports
simultaneously installed for printing, with of course the one, Epson printer
only connected through a printer cable to one of the parallel ports at a
time. And in each case printing was successful by passing the data to be
printed only through one of the two parallel ports, the one labeled LPT2, no
matter whether LPT2 was set to be the motherboard or card parallel port at
the time; trying to print by passing the data to be printed through LPT1, in
each case I obtained the error message “cannot access the port,” no matter
whether LPT1 was set to be the motherboard or the added, card parallel port
at the time. From the successful printing by passing the data to be printed
through the motherboard parallel port in one configuration, I assume that the
hardware in the motherboard parallel port is okay, at least in that
configuration. Likewise from the successful printing by passing the data to
be printed through the parallel port on the added, parallel-port card in
another configuration, I assume that the hardware in the parallel port in the
parallel-port card is okay, too, at least in that configuration. I haven't
found any motherboard jumper to be set for LPT1 or LPT2 at
http://www.uktsupport.co.uk/acer/mb/v58xa.htm or in a brief inspection of the
area of the motherboard near the parallel-port output on the motherboard.
Software for a Lexmark printer is listed in “Printers;” but that Lexmark
printer was not physically cabled to the computer during any of the above
printing tests on which I reported. The computer is in a neighboring state
from me now. I haven't checked lately to see what port the Lexmark printer
is set to use. Even if the Lexmark and Epson printers are set on their
“Details” tabs to use the same, LPT, printer port, I would not expect this to
be a problem because I did not try to print using the two printers and the
same LPT port at the same time; also, as I mentioned, the method I used of in
“Printers” double-clicking on the Epson AP-4000 printer icon and then on the
“General” tab clicking “Print Test Page” ought to insure that one is trying
to print using the Epson AP-4000 printer and not some other printer. I
suppose one could try deleting the Lexmark printer installation in
“Printers;” but given the thinking I already mentioned, it does not seem
logical to me that this would solve the problem of being unable to print
using the port LPT1. What is the explanation for these phenomena using the
IBM Aptiva 2137-E33 computer with a V58XA-1 motherboard in a Windows-95, OSR2
operating system to which a number of Windows-95 updates have been added?
Thanks in advance to anyone who tries to explain or teach me something here.
Pat S.