From: dhliu@solar.csie.ntu.edu.tw (Der-Hua Liu) Subject: Re: DOSEMU 0.47.7 and WordPerfect 5 Date: Thu, 11 Feb 1993 11:31:55 GMT
Andrew Hobson (gt6698a@prism.gatech.EDU) wrote:
: Also, someone has released a dosemu based on Matthias' original dosemu0.4
: that opens a color xterm for display. I'll probably look at this
: and see if we can achieve some sort of merger. His xdos isn't
: terribly fast, and it's not very much different from 0.4, but you
: could always give it a try. (it's in tsx-11.mit.edu /pub/linux/ALPHA/dosemu).
: I currently invoke my pre-0.48 version of dosemu like this (just for info):
: dos -ckVm 720 -Dkx-v > doserr
The xdos hass xterm's sources. It doesn't fork a xterm and pipe the i/o.
My PC is a 486/50 with local-bus VGA, so it may be very slow for 386.
If you think it is too slow, you may replace the font 10x20 with 9x15.
(or smaller font, replace '-fn 10x20' with '-fn xxxxx'. Not always helpful)
Note that xterm can only display fg and bg color text.
The xdos can display 16 colors. And xdos uses the line drawing chars of X, so
you should see better boxes than +---------+. If someone has a X font same as
PC font, it would be better. ( X's font has single-line chars only )
xdos doesn't use term i/o. This eliminates tty r/w.
I think the best approach to write a good dosemu is:
1. Set video pages as read-only. If any dos program wants to
modify the pages, kernel can send signal to dosemu.
2. If there is a continus modifying, set the pages as r/w and do
a entire screen refresh later.
( reducing kernel traps)
It's not easy to implement, considering there are many instructions in x86
to access memeory. ( move [xxxx],yy, rep stosb, ....)
Of course, this approach requires the support of kernel.
Does anybody know how DV/X redirects the outputs of dos programs ?
I am also considering replacing DOS's file system calls with linux's msdos fs
calls. ( only for /dev/hd???) In this way, you can open multiple dos windows
without the danger of file sys crash.
( And possibly faster, eliminate int 13 calls)
I am busy these days. I will quit writing xdosemu after integrating some
features of DOSEMU 0.47.7. If you want to maintain xdosemu, please send me
a mail.
Edward Der-Hua Liu
CS department,
National Taiwan University, Taiwan