( cmd arg1 arg2 -- r )
( Send a command that expects a R1 response, handling CS. )
: SDCMDR1 _sdcSel _cmd _sdcDesel ;

( cmd arg1 arg2 -- r arg1 arg2 )
( Send a command that expects a R7 response, handling CS. A R7
  is a R1 followed by 4 bytes. arg1 contains bytes 0:1, arg2
  has 2:3 )
: SDCMDR7
    _sdcSel
    _cmd                 ( r )
    _idle 8 LSHIFT _idle +  ( r arg1 )
    _idle 8 LSHIFT _idle +  ( r arg1 arg2 )
    _sdcDesel
;