| Routines

ADE8: Insert a pixel column into the message graphic buffer

Used by the routines at AEE8 and B371. Slides the current contents of the message graphic buffer (at 5B00) one pixel to the left, and places the new pixel column into the slot freed up on the right.
Input
A | Pixel column byte
ADE8 | EXX |
ADE9 | LD HL,$5BFF | Point HL' at the end of the graphic buffer at 5B00
ADEC | LD C,$08 | There are 8 pixel rows in the graphic buffer
ADEE | LD B,$20 | Append a pixel to the row and slide all the other pixels one space to the left
ADF0 | RRCA
ADF1 | RL (HL)
ADF3 | DEC HL
ADF4 | DJNZ $ADF1
ADF6 | DEC C | Next pixel row
ADF7 | JR NZ,$ADEE | Jump back until all 8 pixels rows are done
ADF9 | EXX |
ADFA | RET |