J
jd
one with a parallel port.
Thanks
Thanks
one with a parallel port.
Thanks
rwap said:This is becoming more and more of a problem - especially in industry
that is still running equipment from 5 + years ago
FWIW: I bought a conversion cable that takes standard USB input andJoel said:True, although there are certain printers such as the HP LaserJet IV that'll
probably be easily purchased & serviced for at least, say, another decade...
kind of like the VW bug of printers...
For the more "well behaved" programs that didn't directly access the parallel
port hardware, you can just "capture" a parallel port and redirect it to a
network printer (...that speaks "straight ASCII," -- these are still fairly
common in mid- to high-end laser printers). Finally, I believe I've already
seen a product out there that connects to the parallel port of a PC and then
connects to any networked printer; that should work in almost all cases.
The only new inkjet printer on the market that still has a parallel
port is the C88. I believe a few of the more expensive laser printers
also have one, but not many of them.
I do not know if the C88 is DOS compatible.
"jd" said:one with a parallel port.
a dos program will try to write to paralell port, this will be locked
up by windows of presen versions.
networking, USB, all kind of adaptors can not work this way under DOS.
Otto said:People who have some industrial plants operated by DOS software, are
not allowed to run it in some kind of DOS box window under Windows. So
they will not be happy with any adaptors of USB kind etc.
They will need printers runnig from DOS natively, since there are no
propper drivers or hardware which could be operated from DOS to run a
winprinter AFAIK, unless you built it yourself.
The whole computer industry is just running after Microsoft and
forgets, that industry plants need an operating time of more then 10
years often , thus not be able to cope with all kind of gaming fun
produced for home and office user.
dos app requires all the conventional memory possible and won't workThis is in the unlikely event that your
Otto said:dos app requires all the conventional memory possible and won't work
with networking enabled.<
well , networking under DOS, yes this was something one day, but on a
present day TCP/IP Lan with DOS? Yes, the russian DOS (PTS-DOS) had
allways its LOTLAN coming with it, but this is nothing for the TCP/IP
lan we have now.
The DOS apps which ultimatively need to run in native DOS, have to do
it because this is real time use. Nothing to do with memory usage etc.
Example: I did work on building equipment with an industrial robot arm
as one part of it. The arm had a power of abt 6 tons and able to move
very fast. Safety signals, when the arm would touch something had to
be passed immediately to the control computer to give it a stop if
needed. It was possible under DOS or later under w95 and w98 with
special real time drivers being loaded before the windows, so the
serial and paralell ports were handeld in real time. Present day
windows systems explicitely forbid any such application. Dozens of
miliseconds pass until the signal on some port can be processed and
appropriate response sent. By that time , my robot arm might well
destroy the biulding it is placed in...
There are many more examples like driving complex test equipment etc.
rwap said:The only thing is that this makes too many presumptions (along with the
printer industry):
1) That the DOS application can be amended to work with a network port
- most would output direct to LPT1 and I don't know (sorry if I sound
thick), but may not be able to run inside a Windows DOS Box so how do
you re-direct the parallel port to capture it?
2) Real time applications are often running on Programmable Logic
Controllers which do not run DOS but a specific logic control software
which has its own network capabilities (such as ControlNet) - here the
length of time a program takes to run (and even loop times) can be
critical - we are talking of nanoseconds making a difference, as it
may need to monitor up to 255 inputs from various items of hardware
(motors, pecs etc) and set outputs which may change within a couple of
nanoseconds. Printers are critical as often the PLC is housed
somewhere inaccessible where you cannot get to the screen !!
3) Believe it or not but some control systems do not have much memory
(eg. 64K) and so you cannot afford to add extra drivers - you are lucky
if you can send a simple stream of plain text and carriage returns -
the beauty of epsons - need a lot less control codes than PCL language
4) That a regulating authority (BAA and CAA are good examples) will
allow you to network the control equipment (even to just a printer) -
they like to know that the system is completely secure and that the
only way a computer could be connected to it is via the plug on the
front panel (and by someone who has physically gone through security
checks). In most cases you have to get new equipment approved by them
- including printers to ensure that the font used matches their
criteria for easy recognition in all conditions.
Unfortunately, all this is easily forgotten by those who think that a
computer means a Windows controlled desktop or laptop.