Path: utzoo!attcan!uunet!ginosko!gem.mps.ohio-state.edu!uwm.edu!uwvax!puff!rt5.cs.wisc.edu!blochowi
From: blochowi@rt5.cs.wisc.edu (Jason Blochowiak)
Newsgroups: comp.sys.apple
Subject: Re: TWGS speed (and Firmware!)
Keywords: TWgs, Transwarp, Firmware, Applied Engineering, AE
Message-ID: <3182@puff.cs.wisc.edu>
Date: 28 Sep 89 03:03:57 GMT
References: <890926215656.736256@DOCKMASTER.ARPA> <3163@puff.cs.wisc.edu> <35072@apple.Apple.COM>
Sender: news@puff.cs.wisc.edu
Reply-To: blochowi@rt5.cs.wisc.edu (Jason Blochowiak)
Organization: U of Wisconsin CS Dept
Lines: 32

In article <35072@apple.Apple.COM> dlyons@Apple.COM (David Lyons) writes:
>In article <3163@puff.cs.wisc.edu> blochowi@rt5.cs.wisc.edu (Jason Blochowiak) writes:
>>[...] For those of you who know the command to make a JSL from the
>>monitor: Get into the monitor, set native mode, make the call to BC/FF28,
>>and examine the value in the A register. It should be 2 (assuming you're
>>in TransWarp mode).
>How are you examining the A register?  If you let it BRK and look at the
>register dump, that's okay.  Just note that if you "X" something that
>ends with an RTL and then look at the registers with Ctrl-E, you're not
>seeing the registers the way they were after the RTL.

	My, that's certainly annoying... I didn't use the monitor at all, as
I wrote some assembly glue for higher-level Orca/C stuff (so that I could
call the transwarp firmware routines using normal C function calls), and in
this case I did a store to screen memory to make sure the value wasn't getting
toasted somewhere else in the code. Btw, I had forgotten that X was the
proper command (I haven't used many of the monitor's more recent additions),
and so wasn't at all familiar with it's behaviour. Pardon the assumption...

	I suppose that the X command is that way so that things can be X'ed
and a 'R' will still work, eh? Speaking of which - is it legal to change the
values contained in BRK.Var? (Call #$0009 to GetAddr) As in, examine the
things, play with them a bit (e.g. Changing the PC to restart at a different
address), and then let the firmware BRK handler restart the program (by 
clearing the carry bit upon return from an intercepted BreakVector)?

> --Dave Lyons, Apple Computer, Inc.          |   DAL Systems
--
                 Jason Blochowiak - back at school (again).
             blochowi@garfield.cs.wisc.edu or jason@madnix.UUCP

            "What's up pruneface?" - Bugs Bunny in the year 2000