moveHor:
  LDX #$00
  LDY #$0F
  JMP loop
dyix:
  DEY
  INX
  RTS
iydx:
  DEX
  INY
  RTS
clear:
  JSR iydx
  LDA #$00
  STA $410,X
  STA $400,Y
  JSR dyix
  RTS
loop:
  ;draw the pixels
  LDA $fe
  STA $410,X
  LDA $fe
  STA $400,Y
  JSR clear ;erase previous pixels
  JSR dyix
  CPX #$10
  BNE loop
JSR clear
moveVer:
  LDX #$00
  LDY #$e0
  JMP loop2
inc:
  TYA
  CLC
  ADC #$e0
  TAY
  TXA
  CLC
  ADC #$20
  TAX
  RTS
dec:
  TYA
  CLC
  ADC #$20
  TAY
  TXA
  CLC
  ADC #$e0
  TAX
  RTS
clear2:
  JSR dec
  LDA #$00
  STA $410,X
  STA $310,Y
  JSR inc
  RTS
clear3:
  JSR dec
  LDA #$00
  STA $510,X
  STA $210,Y
  JSR inc
  RTS
;draw the first part of the vertical line
loop2: 
  LDA $fe
  STA $410,X
  LDA $fe
  STA $310,Y  
  JSR clear2
  JSR inc  
  BCC loop2
JSR clear2
LDX #$00
LDY #$e0
;draw the second part
loop3: 
  LDA $fe
  STA $510,X
  LDA $fe
  STA $210,Y
  JSR clear3
  JSR inc  
  BCC loop3
JSR clear3
JMP moveHor