[Coco] Becker Port support in MESS

[Richard Goedeken]

Hello everyone,

Since my work to add Becker Port support to the MESS emulator is at a stopping
point, I would like to put this out there for all of you to use.  It's not yet
at a point where it supports all of the configurations and use cases that Bill
wanted for one of his coco emulator starter kits, but it works and is useful
so I thought I should make a little release for all of you.  MESS has a really
good debugger, so it is very nice to use as a software development tool.  This
Becker Port feature extends the usefulness of MESS even further.

Here is a link to the patch for my work:

http://www.fascinationsoftware.com/software/mess/mame-r31554-becker.diff

This diff was taken against the current MESS source code in their SVN
repository, which was at rev 31554 when I created the diff today.  If someone
would like to host this patch file somewhere else (for example on the
DriveWire 4 site), please feel free to do so.

I have also built a binary Win32 executable for anyone who doesn't want to
build from source.  Here is a link to this binary build:

http://www.fascinationsoftware.com/software/mess/mess-r31554-becker.zip

I can also make Linux or OSX builds if anyone would like.  This patch adds a
couple of new system configuration options to the Coco 1/2/3 machines.  There
is one option for enabling or disabling the Becker Port, and another option
for setting the port number.  I don't think there's any way to add a free-form
text configuration option (which would be needed to select a hostname for the
DW server to connect), so I have hard-coded the server name to 'localhost'.
Consequently, you must be running the DW4 server on your local machine in
order to use this.  I have added a port number configuration option, so you
could run multiple DW servers and have different MESS emulator sessions
connected to different servers.

This patch also adds a new mess 'target', which is like a new
computer/machine, named 'coco3dw1'.  This target emulates a Coco3 with a
floppy drive controller containing an HDB-DOS ROM with Becker Port support
instead of the DECB ROM.  You will need a new ROM file in your MESS firmware
directory in order to use the new target, and here is a link to a zip file
containing the required ROM:

http://www.fascinationsoftware.com/software/mess/coco3dw1.zip

So the easiest method of getting yourself running with DW support is use the
new 'coco3dw1' target.  However, there are other options as well.  You could
boot with a normal (coco 1/2/3/3h, whatever) target and mount a floppy disk
image containing a loadable HDB-DOS binary with Becker Port support.  Then
just LOADM and EXEC the HDB-DOS program.  This could be useful if you want to
emulate a Coco 2 with DW or a Coco 3 with the 6309 CPU.

So I hope this is useful to some of you.  I have also filed a request on
mametesters.org to merge this into the MAME project itself, but I have a
feeling that they're unlikely to accept it, due to the nature of the feature.

Regards,
Richard