> ClrMamaPro says that I need to use an old version of two chd I have (sfrush and
> beatmania 1).
> Is there any utility to convert them back to the old 0.77 chd format?
>


You only need an old chd if you're using MAME versions < 78
(or 77u1). If you use 78 (or higher) you most likely use a wrong datfile which doesn't provide sha1 values for chds. If you really want to scan your roms for an older version of MAME, you have to extract the raw image and convert it to an old chdfile with an old hdcomp program.

...my advice: update to 78.

Roman Scherzer
ClrMamePro