**************************************************
* System Call: F$GBlkMp
*
* Function: 
*
* Input:  X = 1024 byte buffer pointer
*
* Output: D = Number of bytes per block
*         Y = Size of system's memory block map
*
*
* Error:  CC = C bit set; B = error code
*
FGBlkMp  ldd   #DAT.BlSz   # bytes per MMU block (8k)
         std   R$D,u       Put into caller's D register
         ldd   <D.BlkMap+2 Get end of system block map ptr
         subd  <D.BlkMap   Subtract start of system block map ptr
         std   R$Y,u       Store size of system block map in caller's Y reg.
         tfr   d,y
         lda   <D.SysTsk   Get system task #
         ldx   <D.Proc     Get caller's task #
         ldb   P$Task,x    get task # of caller
         ldx   <D.BlkMap   Get start ptr of system block map
L0978    ldu   R$X,u       Get addr to put it that caller requested
         os9   F$Move      Move it into caller's space
         rts