freebsd-ports/emulators/pcemu/files

This is an excerpt of what you can see with the standalone "system".
 -- Jörg


1. This looks like PC, but where is DOS? How to get pcemu really running

Pcemu is an emulator that emulates an 8086 CPU as well as a bunch of
PC BIOS services, so it basically provides the functionality like an
old PC/XT.  Anyway, as with the XT too, the emulator requires something
like an operating system to run with.  Since we cannot ship MS-DOS or
one of its variants along with this distribution (for legal reasons),
you're now actually looking at a (sort of) "standalone operating system",
just to get pcemu booted and running.  All this system does is showing
you this introduction.

You will have to replace this mini-system by a physical image of a
DOS boot floppy.  The "system" currently running is booted from the
file

	/usr/local/lib/pcemu/DriveA.

It pretends to be the image of a 720 KB diskette, which has been
chosen as the default bootfile size.

In order to obtain the image of a bootable DOS floppy, do the following:

	Prepare a 720 KB floppy with a DOS system as you'd like
	to run it later.  Include all the good stuff you don't want
	to miss there.  Don't forget to put a simple text editor
	there, so you can modify your configuration files later.

	Put a copy of the file

		/usr/local/lib/pcemu/C/emufs.sys

	onto this diskette, and include a line like

		device = a:\emufs.sys /usr/local/lib/pcemu/C

	into the config.sys file on this diskette.  This will
	provide you with an interface to the BSD file system from
	within your DOS session.  (It actually pretends to be a
	network drive.)  According to David Hedley, you are also
	advised to include the line

		stacks = 9, 512

	there to avoid stack overflow problems with the emulator.

	If you want to retain a copy of the standalone "system" you
	are currently looking at, move it away:

		# cd /usr/local/lib/pcemu; mv DriveA StandaloneA

	Now, make a copy of your disk by either:

	- under BSD, perform a

		# cp /dev/fd0.720 /usr/local/lib/pcemu/DriveA

	  (the number after the fd may vary for drives other than
	  the primary one), or

	- under DOS, copy the file

		/usr/local/lib/pcemu/C/dumpdisk.exe

	  to your DOS system and execute it.  This will dump the
	  physical copy of either drive A or B to the file drivea
	  in your current (DOS) working directory.  You can then move
	  this file to

		/usr/local/lib/pcemu/DriveA

	  in your BSD system.

Since pcemu needs to display the standard VGA font, you further need
to tell your X server about the location of the font file.  It has
been put under

	/usr/local/lib/pcemu/font/

along with the necessary information for the X server.  All you need
to do is to tell your X server about it.  This can either be done
as a server default by including the directory into the FontPath
section of your XF86Config file (this is for XFree86, refer to
the documentation if you're using another X server).  Alternatively,
you can run the command

	$ xset fp+ /usr/local/lib/pcemu/font

when X11 is running to instruct your X server to append this directory
to the font path.  Should you wish to run pcemu across the network,
remember that the fonts must be physically available at the server
side, or you need to provide an X11 font server (xfs).  Refer to
the X11 documentation on how to setup this.


That's all, now you should be able to run pcemu.  Add required
device = a:\emufs.sys /... lines to your config.sys as you
need them.  It's not wise to make the whole BSD hierarchy available
since DOS does not provide multiuser protection.

Should you wish to override some of the emulator defaults like
size and location of the bootfile, you can do this by settig up a
$HOME/.pcemurc file.  Refer to sections 2. and 3. below.



2. Informations about this FreeBSD port


This `port' of pcemu to FreeBSD has been prepared by Jörg Wunsch.
It is an only slightly modified version of David's code, a few
problems have been fixed for the BSD compilation environment, and
the location of the default boot file has been moved in order to
get you started with just what you are reading now.

The PostScript document David is mentioning under 3. below has
been compressed and stored under

	/usr/local/lib/pcemu/doc/report.ps.gz.

It is huge however, so if you don't care much for it you might wish
to remove it later.

Since i'm living in Germany with a German keyboard, i found the
original X11 KeySym to PC scancode translation unacceptable.  Several
scancodes have been unreachable for me.  Hence i decided to add another
section to the .pcemurc file allowing to instruct pcemu of specific
keyboard layout semantics.  They consist of the keyword keymap,
followed by the desired PC scancode, an equal sign, and the character
that is generated for this key under X11 without any shift keys.  (Note
that no space is allowed on either side of the equal sign.)  This way
i won't get a German key mapping under DOS, but at least a valid keyboard
layout where all the scan codes can actually be generated at all.

The appropriate section of my .pcemurc file looks like:

keymap 12=ß
keymap 13='
keymap 21=z
keymap 26=]
keymap 27=+
keymap 39=\
keymap 40=[
keymap 41=^
keymap 43=#
keymap 44=y
keymap 53=-
keymap 86=<


Once :-) i will have filed all my modifications back to David, and
perhaps they will be included into the regular distribution as well.

Should you wish to contact me regarding this FreeBSD port, you can
reach me as joerg_wunsch@uriah.heep.sax.de.