Again: serial communication for legacy DOS applications

[Jean Pion]

Sorry Malke, but the first post was a slip of my mouse, accidents happen?

This mail server seems to have little entries, so i've missed the tread,
again, sorry.

Okay I was not clear, English is not my native tongue.

What I'm having trouble with is serial communication, i.e. rs232.
Like terminal programs for example.
We use a lot of dos programs that send data serialy to electronic displays.
Ofcourse this al happens by poking data directly into the uart.
The thing is that there are no violations or system errors,
but the communication is unreliable.Most protocol resends messed up packets
(or timed out) to some extent, e.g. 3 retries.
Then it gives up. Usualy with a direct connection there are no errors.
Except on the XP machines... The first packets seem to work fine...
But in fact the communication is so bad, it is unusable!
What can it be?

Thanks in advance, Jean

BTW It has not to do with printing, which uses the parallel port....

 

[Malke]

Sorry Malke, but the first post was a slip of my mouse, accidents
happen?

This mail server seems to have little entries, so i've missed the
tread, again, sorry.

Okay I was not clear, English is not my native tongue.

What I'm having trouble with is serial communication, i.e. rs232.
Like terminal programs for example.
We use a lot of dos programs that send data serialy to electronic
displays. Ofcourse this al happens by poking data directly into the
uart. The thing is that there are no violations or system errors,
but the communication is unreliable.Most protocol resends messed up
packets (or timed out) to some extent, e.g. 3 retries.
Then it gives up. Usualy with a direct connection there are no errors.
Except on the XP machines... The first packets seem to work fine...
But in fact the communication is so bad, it is unusable!
What can it be?

Thanks in advance, Jean

BTW It has not to do with printing, which uses the parallel port....

Hey, I can't speak French (except for "cooking French"!) so don't worry
about it. What I think is happening is that many DOS programs interact
directly with the hardware. This is forbidden in XP, and this is a Good
Thing for stability. Unfortunately, my advice would be to 1) check with
each of the programs' manufacturers for updates and/or tech support; 2)
or look for newer programs designed to run under XP that will do what
you want; or 3) keep some computers around running older operating
systems such as Win98SE for these applications.

Good luck,

Malke

 

[Jean Pion]

Hey, I can't speak French (except for "cooking French"!) so don't worry
about it. What I think is happening is that many DOS programs interact
directly with the hardware. This is forbidden in XP, and this is a Good
Thing for stability. Unfortunately, my advice would be to 1) check with
each of the programs' manufacturers for updates and/or tech support; 2)
or look for newer programs designed to run under XP that will do what
you want; or 3) keep some computers around running older operating
systems such as Win98SE for these applications.

Good luck,

Malke
--

I know for a fact that these programs directly interact with the hardware.
This was required because in the old days system calls proved to be
unreliable for fast serial communication.

But I disagree that that direct harware access is *forbidden* because:
1) then it should cause a system error message like access violation...
2) it can not work a little bit, then it should not work at all...

And furter more Win2k is fairly strict in direct hardware access,
but does so in a stable way. Stability is maitained as long as
only one process (dos box) is allowed to (indirectly) use specific hardware.
And ofcourse crashing one process (dos box) doesn't crash other processes.

So my guess is that hardware access is not an issue here here.
I think that the hardware is emulated in a better way in Win2k than in
WinXP.
Maybe it has to do with efficiency or interrupt handling.

So I was wondering if others experience the same, and what could be done.

Regards, Jean.

 

[Malke]

I know for a fact that these programs directly interact with the
hardware. This was required because in the old days system calls
proved to be unreliable for fast serial communication.

But I disagree that that direct harware access is *forbidden* because:
1) then it should cause a system error message like access
violation...
2) it can not work a little bit, then it should not work at all...

And furter more Win2k is fairly strict in direct hardware access,
but does so in a stable way. Stability is maitained as long as
only one process (dos box) is allowed to (indirectly) use specific
hardware. And ofcourse crashing one process (dos box) doesn't crash
other processes.

So my guess is that hardware access is not an issue here here.
I think that the hardware is emulated in a better way in Win2k than in
WinXP.
Maybe it has to do with efficiency or interrupt handling.

So I was wondering if others experience the same, and what could be
done.

Very interesting reasoning, Jean. You certainly may be right. I hope you
get a more definitive answer than I can give you. Since I'm a practical
sort, my advice would be to just keep using Win2k.

Good luck,

Malke

 

[Si Ballenger]

So my guess is that hardware access is not an issue here here.
I think that the hardware is emulated in a better way in Win2k than in
WinXP.
Maybe it has to do with efficiency or interrupt handling.

So I was wondering if others experience the same, and what could be done.

I don't think that is is a hardware access issue, but some type
of older library call to the serial port that XP does not
support. Having user level access to the hardware in XP does not
solve the issue.

 

[Alex Nichol]

What I'm having trouble with is serial communication, i.e. rs232.
Like terminal programs for example.
We use a lot of dos programs that send data serialy to electronic displays.
Ofcourse this al happens by poking data directly into the uart.
The thing is that there are no violations or system errors,
but the communication is unreliable.Most protoco

You are lucky to have managed to get data out at all. XP will totally
prevent programs from directly handling hardware - you can send to a
serial port through standard DOS call, but nothing more

Get away from DOS