NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/comp/compress/4440

Text File | 1993-01-07 | 1.7 KB | 35 lines

Newsgroups: comp.compression
Path: sparky!uunet!stanford.edu!nntp.Stanford.EDU!kocherp
From: [e-mail] (Paul Carl Kocher)
Subject: Re: PKZip 2.04c quick impressions (Screen problems)
Message-ID: <[e-mail]>
Sender: [e-mail] (Mr News)
Organization: DSG, Stanford University, CA 94305, USA
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Thu, 7 Jan 93 23:44:05 GMT
Lines: 23

In article <[e-mail]> [e-mail] (Timo Salmi) writes:
>Here is one more feature to ponder.  I use a screen scrollback
>buffer (buffit30) which captures bios screen writes to a buffer.
>Very handy for some purposes.  The new pkzip confuses it.  The only
>things that get sent are the eolns, so that if you look at the
>scroll-back buffer you are faced with blank pages.  Perhaps 2.04
>uses some kind of a weird mix of bios and direct screen writes.  A
>frustrating feature.  I wish there were some method of turning off
>the direct writes.

While looking at the encryption yesterday, I noticed that the program
seemed to be using interrupt 29, of all things, to do its screen writes.
According to _DOS_Programmer's_Reference_ (published by QUE), this is
"fast putchar," but is a reserved function used internally by DOS only.
The entry concludes, "This interrupt is intended for use with DOS
device drivers, and is not documented as being supported beyond DOS
V2.0.  It is _not_ to be used in applications programs."

From the code it looked like there might be a way to disable this,
though I have no idea what it might be.  (Might try ">con"...)

-- Paul Kocher
[e-mail]