Use byte pointers for the import method

src/sudoku.s

@@ -39,8 +39,8 @@ START:  MOVE  P,[-PDLLEN,,PDL-1]       ;Initialize the stack.
         PUSHJ P,GETJCL                 ;Read the command line.
         MOVE  A,[BPTR,,LOADING]        ;Print the loading message
         PUSHJ P,OUTSTR
-        MOVEI A,FNAME1                 ;Store the first file name in A
-        MOVEI B,FNAME2                 ;Store the second file name in B
+        MOVEI A,[BPTR,,FNAME1]         ;Store the first file name in A
+        MOVEI B,[BPTR,,FNAME2]         ;Store the second file name in B
         MOVEI C,FIELD                  ;Store the address of field in C
         PUSHJ P,IMPRTF                 ;Load the file
         PUSHJ P,PFIELD                 ;Print the loaded field.
@@ -139,7 +139,7 @@ IMPRTF: PUSH  P,A                      ;Save the A register.
         MOVE  X,[440400,,FIELD]        ;Init a 4-bit byte pointer to FIELD.
         .CALL [SETZ ? SIXBIT/OPEN/     ;Open a file descriptor.
             [.UAI,,CHDSKI] ? [SIXBIT/DSK/] ;Mode, channel and device name
-                [%CLIN,,A] ? [%CLIN,,B] ? ((SETZ))]
+                A ? B ((SETZ))]
          .LOSE %LSFIL                  ;Handle errors after opening the file
 IMPRD:  .IOT  CHDSKI,A                 ;Read an ascii char into A.
         JUMPL A,IMPREX                 ;If there was nothing read, exit.