>My first thought is to disassemble the SCSI driver
>in the Macintosh ROM to find out how to operate the
>DMA controller.  I have MacsBug, and I also have a
>very complete looking table of ROM entry points (from
>the MPW-GM distribution which is freely downloadable
>from Apple).  MacsBug has some capability of doing
>symbolic disassembly, but I haven't been able to
>figure out how to get my symbol table of the ROM
>into MacsBug.  Anybody know how to do this?  If not,
>any other suggestions on how I might proceed?

If you are even THINKING of disassembling 68K code, particularly for 
the Mac, get Steve Jasik's MacNosy disassembler!

email: macnosy@jasik.com
website: http://www.jasik.com

Dan Killoran