.
.  Define equates used to reference fields in the SMU Communications Block (SCB)
.  Note - only fields referenced from assembly language are defined.
.
scbsize    equ     50*8         .Length of SCB.
scbvecsim  equ     1*8+1        .Vector simulation control (3 bytes)
scbidler   equ     2*8          .Non-zero if IDLE is requested.
scbstepr   equ     2*8+2        .Non-zero if STEP is requested.
scbnsrv    equ     3*8          .Flag to indicate 180 is alive and well.
.
