As commented, this is the case for ATA-1, -2, -3, -4, and -5. The CFFA2 Apple
II IDE card firmware relies on this value being as documented in the standards
to properly detect the drive size, and none of the usual sensitive Atari/Midway
games are broken by the change.
(This field is unused in ATA-6 and later).
idectrl.c [Peter Ferrie]
- correct status flags for multi-sector reads
- implement more correct controller reset values
- fix phantom slave drive detection problem
Causes problems noted with many MAME games such as Area 51: Site 4, Primal Rage 2, All Viper.c games among others that are either not starting or constantly RE-starting looking for proper IDE communications.
device_memory_interface::space() assert against NULL and
return a reference, and pushed references throughout all
address space usage in the system. Added a has_space()
method to check for those rare case when it is ambiguous.
[Aaron Giles]
Also reinstated the generic space and added fatal error
handlers if anyone tries to actually read/write from it.
from 4 to 5. This means any diff CHDs will no longer work. If you
absolutely need to keep the data for any existing ones you have,
find both the diff CHD and the original CHD for the game in question
and upgrade using these commands:
rename diff\game.dif diff\game-old.dif
chdman copy -i diff\game-old.dif -ip roms\game.chd -o diff\game.dif -op roms\game.chd -c none
Specifics regarding this change:
Defined a new CHD version 5. New features/behaviors of this version:
- support for up to 4 codecs; each block can use 1 of the 4
- new LZMA codec, which tends to do better than zlib overall
- new FLAC codec, primarily used for CDs (but can be applied anywhere)
- upgraded AVHuff codec now uses FLAC for encoding audio
- new Huffman codec, used to catch more nearly-uncompressable blocks
- compressed CHDs now use a compressed map for significant savings
- CHDs now are aware of a "unit" size; each hunk holds 1 or more units
(in general units map to sectors for hard disks/CDs)
- diff'ing against a parent now diffs at the unit level, greatly
improving compression
Rewrote and modernized chd.c. CHD versions prior to 3 are unsupported,
and version 3/4 CHDs are only supported for reading. Creating a new
CHD now leaves the file open. Added methods to read and write at the
unit and byte level, removing the need to handle this manually. Added
metadata access methods that pass astrings and dynamic_buffers to
simplify the interfaces. A companion class chd_compressor now
implements full multithreaded compression, analyzing and compressing
multiple hunks independently in parallel. Split the codec
implementations out into a separate file chdcodec.*
Updated harddisk.c and cdrom.c to rely on the caching/byte-level read/
write capabilities of the chd_file class. cdrom.c (and chdman) now also
pad CDs to 4-frame boundaries instead of hunk boundaries, ensuring that
the same SHA1 hashes are produced regardless of the hunk size.
Rewrote chdman.exe entirely, switching from positional parameters to
proper options. Use "chdman help" to get a list of commands, and
"chdman help <command>" to get help for any particular command. Many
redundant commands were removed now that additional flexibility is
available. Some basic mappings:
Old: chdman -createblankhd <out.chd> <cyls> <heads> <secs>
New: chdman createhd -o <out.chd> -chs <cyls>,<heads>,<secs>
Old: chdman -createuncomphd <in.raw> <out.chd> ....
New: chdman createhd -i <in.raw> -o <out.chd> -c none ....
Old: chdman -verifyfix <in.chd>
New: chdman verify -i <in.chd> -f
Old: chdman -merge <parent.chd> <diff.chd> <out.chd>
New: chdman copy -i <diff.chd> -ip <parent.chd> -o <out.chd>
Old: chdman -diff <parent.chd> <compare.chd> <diff.chd>
New: chdman copy -i <compare.chd> -o <diff.chd> -op <parent.chd>
Old: chdman -update <in.chd> <out.chd>
New: chdman copy -i <in.chd> -o <out.chd>
Added new core file coretmpl.h to hold core template classes. For now
just one class, dynamic_array<> is defined, which acts like an array
of a given object but which can be appended to and/or resized. Also
defines dynamic_buffer as dynamic_array<UINT8> for holding an
arbitrary buffer of bytes. Expect to see these used a lot.
Added new core helper hashing.c/.h which defines classes for each of
the common hashing methods and creator classes to wrap the
computation of these hashes. A future work item is to reimplement
the core emulator hashing code using these.
Split bit buffer helpers out into C++ classes and into their own
public header in bitstream.h.
Updated huffman.c/.h to C++, and changed the interface to make it
more flexible to use in nonstandard ways. Also added huffman compression
of the static tree for slightly better compression rates.
Created flac.c/.h as simplified C++ wrappers around the FLAC interface.
A future work item is to convert the samples sound device to a modern
device and leverage this for reading FLAC files.
Renamed avcomp.* to avhuff.*, updated to C++, and added support for
FLAC as the audio encoding mechanism. The old huffman audio is still
supported for decode only.
Added a variant of core_fload that loads to a dynamic_buffer.
Tweaked winwork.c a bit to not limit the maximum number of processors
unless the work queue was created with the WORK_QUEUE_FLAG_HIGH_FREQ
option. Further adjustments here are likely going to be necessary.
Fixed bug in aviio.c which caused errors when reading some AVI files.
