NNTP-Posting-Date: Tue, 22 Jul 2003 11:34:53 -0500 From: "Teece" Newsgroups: comp.os.msdos.djgpp Subject: New to djgpp. Questions about protected mode, etc. Date: Tue, 22 Jul 2003 09:34:52 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01C35034.810BEDF0" X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4910.0300 Message-ID: <3iGdna0c9-Mz-oCiU-KYvA@giganews.com> Lines: 121 X-Trace: sv3-GmYAFjutpE7mLfM1vEK5nqfT9tHZIzm6gh+gUUhLmRlTHpkESwPzQclF0nppHv5XhR2IPeBDQTxPh7q!p7i7wr8qkeZgIiBb1SJgQ6OIBhvFXOE6pQeeBdIE75E51999vuBKYJNPWw== X-Complaints-To: abuse AT giganews DOT com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.1 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com This is a multi-part message in MIME format. ------=_NextPart_000_000A_01C35034.810BEDF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Please bear with me since I am not all that sure about how to ask the = questions that I have. I have an application that I want to develop for the PC with special = hardware that will run on the PCI bus. I will need to send data from the = program directly to the hardware. It is not necessary that I use a = sophisticated operating system like XP or even any version of Windows. = Therefore I can avoid the difficulty of writing Windows device drivers = for the new hardware, etc. I suppose that I could go a couple of ways. One way would be to use good = old DOS, which does not run in protected mode, and use DJGPP (or VC1.52, = I think) to obtain an executable. Since DOS does not know about = protected mode I would not cause a segmentation fault when I directly = access the PCI hardware. Is this correct? I was reading in the DJGPP documentation that DJGPP has a DOS extender. = This was described as a layer of software that "traps the call, switches = the CPU to real mode, reissues the call, waits for the service to do its = thing, then switches the CPU back into protected mode, and returns to = the application code that called the real-mode service".=20 Does Windows have a DOS extender? Is it not possible to run old DOS = programs on XP in what passes for a DOS emulator?=20 Does Linux have a DOS extender? Will an executable made with DJGPP run = on Linux? Thank You Tom tom_cip_11551 AT hotmail DOT com ------=_NextPart_000_000A_01C35034.810BEDF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Please bear with me since I am not all = that sure=20 about how to ask the questions that I have.

I have an application that I want to = develop for=20 the PC with special hardware that will run on the PCI bus. I will need = to send=20 data from the program directly to the hardware. It is not necessary that = I use a=20 sophisticated operating system like XP or even any version of Windows. = Therefore=20 I can avoid the difficulty of writing Windows device drivers for the new = hardware, etc.

I suppose that I could go a couple of = ways. One way=20 would be to use good old DOS, which does not run in protected mode, and = use=20 DJGPP (or VC1.52, I think) to obtain an executable. Since DOS does = not=20 know about protected mode I would not cause a segmentation fault when I = directly=20 access the PCI hardware. Is this correct?

I was reading in the DJGPP = documentation that DJGPP=20 has a DOS extender. This was described as a layer of software that = "traps the call, = switches the CPU to=20 real mode, reissues the call, waits for the service to do its thing, = then=20 switches the CPU back into protected mode, and returns to the = application code=20 that called the real-mode service".

Does Windows have a DOS extender? Is it not possible to run old = DOS=20 programs on XP in what passes for a DOS emulator? =

Does Linux have a DOS extender? Will an executable = made with=20 DJGPP run on Linux?

Thank You

Tom

tom_cip_11551 AT hotmail DOT com

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