Screen buffer: ShowBufferBlock

       Name: ShowBufferBlock                                         [Show more]
       Type: Subroutine
   Category: Screen buffer
    Summary: Update the player's scrolling landscape view by copying an 8-byte
             character block from the screen buffer into screen memory
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * ShowBufferColumn calls ShowBufferBlock
             * ShowBufferRow calls ShowBufferBlock


 Arguments:

   fromAddr(1 0)        The source address from which we copy the eight-byte
                        character block

   toAddr(1 0)          The destination address to which we copy the eight-byte
                        character block


.ShowBufferBlock

 LDY #0                 \ Copy byte #0 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #1 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #2 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #3 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #4 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #5 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #6 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 INY                    \ Copy byte #7 of fromAddr(1 0) to toAddr(1 0)
 LDA (fromAddr),Y
 STA (toAddr),Y

 RTS                    \ Return from the subroutine