SAM chip vectors.$FFC0-$FFDF (65472-65503)

   

  The sam is accessed through the address bus hence data on the data bus is 
irrelevent at that time.To set a SAM register write to the ODD address given 
and to clear a SAM address write to the EVEN address given.

       Dec           Hex        Description
       65472-65477   FFC0-FFC5  VDG mode (SAM)

                 GRAPHIC    MODE>: DMA G6R/C G3R G3C G2R G2C G1C/R AI,AE,S4,S6
       65472:65473   FFC0:FFC1      1   0     1   0   1   0   1        0
       65474:65475   FFC2:FFC3      1   1     0   0   1   1   0        0
       65476:65477   FFC4:FFC5      1   1     1   1   0   0   0        0

       65478-65491   FFC6-FFD3  Offset of base VDG screen(ie.text)
                                Address of base screen=0000+(offset*512)
       65478:65479   FFC6:FFC7  BIT0
       65480:65481   FFC8:FFC9  BIT1
       65482:65483   FFCA:FFCB  BIT2
       65484:65485   FFCC:FFCD  BIT3
       65486:65487   FFCE:FFCF  BIT4
       65488:65489   FFD0:FFD1  BIT5
       65490:65491   FFD2:FFD3  BIT6
       65492:65493   FFD4:FFD5  Page select:MPU addresses one of two 32K chunks
                                (Ignored on D32)
       65494-65497   FFD6-FFD9  MPU rate
                                FAST  FAST  ADDR. DEP(ROM FAST)  SLOW
       65494:65495   FFD6:FFD7   1     0            1              0
       65496:65497   FFD8:FFD9   1     1            0              0
       65498-65501   FFDA-FFDD  Memory size
                                64K STATIC    64K    1 or 2*16K     1 or 2*4K
       65498:65499   FFDA:FFDB       1         0         1              0
       65500:65501   FFDC:FFDD       1         1         0              0
       65502:65503   FFDE:FFDF  Map type-0:Upper 32K ROM
                                         1:Upper 32K RAM

    MPU Vectors $FFE0-$FFFF (65504-65535)

       65504-65521   FFE0-FFF1  Reserved for future MPU enhancements
       65522:65523   FFF2:FFF3  SWI3 vector
       65524:65525   FFF4:FFF5  SWI2 vector
       65526:65527   FFF6:FFF7  FIRQ vector
       65528:65529   FFF8:FFF9  IRQ vector
       65530:65531   FFFA:FFFB  SWI vector
       65532:65533   FFFC:FFFD  NMI vector
       65534:65535   FFFE:FFFF  RESET vector

        The SAM maps ROM at $BFF2-$BFFF over these vectors:
         RESET vectored straight to ROM at $B3B4
         Rest go via jump table in Page 1 of RAM (see map)