Jim <wdxp@cox.net> wrote:
USB-serial converters have all the signals.
The problem is that they will not work with some old (DOS) software.

Re: "USB-serial converters have all the signals."

that is simply wrong. They are not real serial ports, they do not have
UART registers (8250-compatible serial port registers), and if the
software for the device expects to communicate with the device by
programming such registers, that software will NOT work. And this
applies to quite a few devices and their WINDOWS software and device
drivers, for example my Qualcom QCP-860 cell phone, and I could list
LOTS more. In fact, only about half of all serial devices will work
with a USB to serial converter.


Ian Stirling wrote:

Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
They have all the RS232 signals, and work exactly as any other serial port
through windows calls.
Anything that tries to access the registers will fail.
Windows programs that access the registers directly are barking mad.
The phone would almost certainly work fine with a USB serial converter if
the software on the PC was upgraded.

I have to wonder why windows does not simply provide a fake software
UART by trapping the registers and emulating a 8250/16550 compatible port.

Here is the problem with your post: They have all ... work exactly as
any other serial port through windows calls.""

THROUGH WINDOWS CALLS

The problem is that in the real world, about half of the software and
drivers that were written to access serial port hardware devices don't
exclusively use "Windows Calls", and I AM talking about "Windows
Software" and not "DOS" software.

You can argue all you want that the fault lies with the firms and
programmers who wrote that software, and frankly I'd agree with you.

But none of that matters in the real world. If you want to use lots of
cell phones, serial scanners (PaperPort Strobe), serial GPS receivers,
some PDAs, etc., etc., etc. then a USB to serial port converter simply
won't work, and your posts, first that they would, and then that they
"should", are simply both wrong and irrelevant.

Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
Jims original comment was
"
I have a laptop on order and just realized it has no serial port,
which my Sprint PCS phone requires to interface with the computer. Is
there any way I can add a Serial PCMIA card to this computer that will
work with the phone, as I understand the USB - SERIAL converters are
not true serial ports with all the various handshaking, etc.
"

I was specifically commenting on the fact that the comment about handshaking
is incorrect, USB cables have all the signals, including handshaking.
I did not say that they will work with all hardware.
As to your response, signals and registers are totally different things.