X-Authentication-Warning: delorie.com: mail set sender to opendos-bounces using -f Message-ID: From: "da Silva, Joe" To: "'opendos AT delorie DOT com'" Subject: RE: X00 and other stuff, com speed with m$dos 6.22 Date: Thu, 19 Feb 2004 09:48:39 +1100 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C3F671.59A1F730" Reply-To: opendos AT delorie DOT com This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C3F671.59A1F730 Content-Type: text/plain Ah, I see ... if the program doesn't support higher baud rates _and_ it uses Int 14h to set the baud rate, X00 can provide other options without the program's knowledge. Gotcha! Joe. > -----Original Message----- > From: shadow AT shadowgard DOT com [SMTP:shadow AT shadowgard DOT com] > Sent: Wednesday, February 18, 2004 6:03 PM > To: opendos AT delorie DOT com > Subject: RE: X00 and other stuff, com speed with m$dos 6.22 > > On 18 Feb 2004 at 13:10, da Silva, Joe wrote: > > > > > Hmmm ... If the program _doesn't_ mess around with the > > UART registers, it _can't_ use anything higher than 19k2. > > Sure it can. If it uses the INT 14 calls to set the baud rate and to > send bytes toand receive bytes from the serial port, then it will not > *know* what rate the UART is actually running at. > > The *program* can think it's running at 19.2k. But X00 can run it at > any rate it feels like. > > Also, if you've got source or can find where the baud rate divisors > are stored in a program, you can make a program that directly > accesses UART registers work at higher baud rates. A common move was > to replace the values for rates below 300 with those for rates > *above* 19.2k > > > -- > Leonard Erickson (aka shadow) > shadow at krypton dot rain dot com > ------_=_NextPart_001_01C3F671.59A1F730 Content-Type: text/html Content-Transfer-Encoding: quoted-printable RE: X00 and other stuff, com speed with m$dos 6.22

Ah, I see ... if the = program doesn't support higher baud rates
_and_ it uses Int = 14h to set the baud rate, X00 can provide
other options = without the program's knowledge. Gotcha!

Joe.

    -----Original Message-----
    From:   shadow AT shadowgard DOT com = [SMTP:shadow AT shadowgard DOT com]
    Sent:   Wednesday, February 18, 2004 6:03 PM
    To:     opendos AT delorie DOT com
    Subject:       = RE: X00 and other stuff, com speed = with m$dos 6.22

    On 18 Feb 2004 at 13:10, da Silva, Joe = wrote:

    >
    > Hmmm ... If the program = _doesn't_ mess around with the
    > UART registers, it _can't_ use = anything higher than 19k2.

    Sure it can. If it uses the INT 14 = calls to set the baud rate and to
    send bytes toand receive bytes from = the serial port, then it will not
    *know* what rate the UART is actually = running at.

    The *program* can think it's running = at 19.2k. But X00 can run it at
    any rate it feels like.

    Also, if you've got source or can find = where the baud rate divisors
    are stored in a program, you can make = a program that directly
    accesses UART registers work at = higher baud rates. A common move was
    to replace the values for rates below = 300 with those for rates
    *above* 19.2k


    --
    Leonard Erickson (aka shadow)
    shadow at krypton dot rain dot = com

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