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Article #3608Re: H-E-L-P!! An interesting UART problem.
From: Ron Dippold
Date: Wed, 11 Nov 1992 22:26
Date: Wed, 11 Nov 1992 22:26
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ilan@seas.gwu.edu (Ilan Berkner) writes: >The only way to do this would be to either: >1. Attach an ISR to vector 14h, and _hope_ that all of your client's > software will only be using int 14h calls to xmit data. This is > like hoping that the moon will turn around in orbit so you can see > the other side. >2. or put the computer into virtual mode, and write an ISR that traps > 386 I/O priviledge exceptions. This technique will only work on > 386-class machines, and is incompatible with Windows enhanced mode, > 386MAX, QEMM, Desqview, OS/2 2.0, etc. >Sorry, but there's no way to trap I/O, and the UART can't do interrupts >on transmits, as you found out. 3. Just do a loop back... that way you're dealing with actual receive interrupts. -- You have all the leadership potential of a caboose.
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Newsgroups: comp.os.msdos.programmer,comp.sys.ibm.pc.programmer Path: arc1-ca.pugleaf.net!sparky!uunet!charon.amdahl.com!pacbell.com!att-out!walter!qualcom.qualcomm.com!qualcom!rdippold From: rdippold@qualcom.qualcomm.com (Ron Dippold) Subject: Re: H-E-L-P!! An interesting UART problem. Message-ID: <rdippold.721520794@qualcom> Sender: news@qualcomm.com Nntp-Posting-Host: qualcom.qualcomm.com Organization: Qualcomm, Inc., San Diego, CA References: <1992Nov10.094131.9300@iccgcc.decnet.ab.com> <1992Nov11.141104.7451@seas.gwu.edu> Date: Wed, 11 Nov 1992 22:26:34 GMT Lines: 18