| Startup routines

80CC: Copy data from a row of the screen

Used by the routine at 81C8. Copies 256 bytes of data from a row of the screen to its destination, in eight 32-byte blocks.
Input
HL | Source (4000 or 50E0)
DE | Destination (5D60 or 5E60)
80CC | PUSH HL |
80CD | LD BC,$0020 | There are 32 bytes per block (row of pixels)
80D0 | LDIR | Copy 32 bytes to the destination
80D2 | POP HL |
80D3 | INC H | Point HL at the next block of 32 bytes to copy
80D4 | BIT 3,H | Have we copied 8 blocks yet?
80D6 | JR Z,$80CC | Jump back if not
80D8 | RET |