3b1emu: changelog

changelog

Wed, 16 Apr 2014 02:20:43 -0600
by andrew@localhost [Wed, 16 Apr 2014 02:20:43 -0600] rev 147
fixed bus error handling for real this time (save registers before every instruction and push the saved registers if a bus error occurs, since the instruction may have changed registers before the bus error, and also stop the instruction immediately with longjmp so it won't change memory after the bus error)

This isn't actually what a real 68k does, but it is a good enough approximation. A real 68k will jump back into the middle of the faulted instruction and resume it from the memory access that faulted as opposed to restarting from the beginning like this CPU emulation does. It would be a lot harder to do that with the way this CPU library is designed. Newer versions of MESS basically do the same thing (they use a newer version of this library).

Tue, 21 May 2013 22:48:32 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Tue, 21 May 2013 22:48:32 +0100] rev 145
Code clean up

* Tighten optimisation and warning options to find more potential issues
* Remove unused variable in keyboard code
* Display error message if ROMs fail to load
* Fix format string bugs in WD2010

Fri, 12 Apr 2013 16:26:25 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 12 Apr 2013 16:26:25 +0100] rev 144
Don't set PS1 if there is a level-7 interrupt or bus error

PS1 should only be set if the page was originally present (PS1 or PS0 set). If
PS0 and PS1 are clear (page not present) then do NOT set PS1.

Once again the TRM is blatantly and spectacularly wrong...

Fri, 12 Apr 2013 12:37:34 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 12 Apr 2013 12:37:34 +0100] rev 143
Flush stderr after printing debug messages

Fri, 12 Apr 2013 12:37:13 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 12 Apr 2013 12:37:13 +0100] rev 142
Make the page table volatile (it may change behind gcc's back)

Fri, 12 Apr 2013 12:36:28 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 12 Apr 2013 12:36:28 +0100] rev 141
Make mapper debug logic more verbose (but disable by default)

Fri, 12 Apr 2013 12:34:32 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 12 Apr 2013 12:34:32 +0100] rev 140
Fix read-after-write logic

In some cases (notably reading from a page after having written to it), the
mapper may change the pagestate from "accessed and written" ("dirty"; PS0,PS1)
to "accessed but not written" (clean; PS1,!PS0). This should never, ever, EVER
happen. Once a page is dirty, it remains so until the 68k clears the DIRTY
bit.

Once again, this wonderful bit of logic was missing from the TRM.

Thu, 11 Apr 2013 09:37:25 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Thu, 11 Apr 2013 09:37:25 +0100] rev 139
Fix potential unassigned variable

Thu, 11 Apr 2013 09:37:11 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Thu, 11 Apr 2013 09:37:11 +0100] rev 138
Check return value of fread()

Thu, 11 Apr 2013 09:36:53 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Thu, 11 Apr 2013 09:36:53 +0100] rev 137
Enable code optimisation to improve quality of GCC warnings

Thu, 11 Apr 2013 09:18:31 +0100
by Philip Pemberton <philpem@philpem.me.uk> [Thu, 11 Apr 2013 09:18:31 +0100] rev 136
Code cleanup

* Fix some compiler warnings --
* string format
* shift greater than type size,
* unused variable.

Wed, 13 Mar 2013 01:10:34 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Wed, 13 Mar 2013 01:10:34 +0000] rev 135
merge changes from default

Wed, 13 Mar 2013 00:43:25 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Wed, 13 Mar 2013 00:43:25 +0000] rev 134
[wd2010,main] WD2010 disc geometry fixes

I believe I have fixed the geometry problem with FreeBee. The geometry was set
to 17 sectors per track instead of 16, which obviously throws off addressing.
I changed it to use 16 sectors per track. However, s4diag tries to format
sector 17, so I changed the WD2010 emulation to accept any address when
formatting (since the format command doesn't actually do anything, it doesn't
matter). It is now possible to format the hard disk, initialize the file
system, and mount it. However, cpio still fails to copy the system to the hard
disk.

Author: Andrew Warkentin <andreww591 gmail com>

Wed, 13 Mar 2013 00:40:42 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Wed, 13 Mar 2013 00:40:42 +0000] rev 133
use MAP_ADDR_TO_PAGE for memory mapping

Fri, 18 Jan 2013 22:52:43 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 18 Jan 2013 22:52:43 +0000] rev 132
merge in changes from default branch

Fri, 18 Jan 2013 18:51:50 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 18 Jan 2013 18:51:50 +0000] rev 131
add TODO

Fri, 18 Jan 2013 17:20:07 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 18 Jan 2013 17:20:07 +0000] rev 130
[wd2010] disable DMA pagefault workaround (no longer required)

Fri, 18 Jan 2013 17:18:50 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 18 Jan 2013 17:18:50 +0000] rev 129
[memory] Emulate main memory read wrap-around

3B1s with 512K or 1MB of base memory have a decoding quirk which causes reads
to 'wrap around'. That is to say, on a 512K machine, reading from addresses 0,
512K, 1024K or 1536K will address the same RAM byte. On a 1MB machine,
addresses 0 and 1024K address the same RAM byte.

Emulating this incorrectly causes P4TEST to report an incorrect amount of
available base RAM.

Fri, 18 Jan 2013 17:03:48 +0000
by Philip Pemberton <philpem@philpem.me.uk> [Fri, 18 Jan 2013 17:03:48 +0000] rev 128
experimental memory mapper, not quite working