Routines
Prev: 54280 Up: Map Next: 54504
54281: Write Scene To Shadow Buffer
Used by the routines at RunHandlers, SelectionScreen and Handler_TickerNews.
WriteSceneToShadowBuffer 54281 LD BC,0 BC=0000.
Self-modifying code. These lines populate the value for a LoaD command below. The values relate to areas of the shadow screen buffer:
54284 LD A,107 Write 107 to:
54286 LD (54389),A
54289 LD (54454),A
54292 CALL WriteSceneToShadowBuffer_Loop_1 Call WriteSceneToShadowBuffer_Loop_1.
54295 LD A,115 Write 115 to:
54297 LD (54389),A
54300 LD (54454),A
54303 CALL WriteSceneToShadowBuffer_Loop_1 Call WriteSceneToShadowBuffer_Loop_1.
54306 LD A,123 Write 123 to:
54308 LD (54389),A
54311 LD (54454),A
WriteSceneToShadowBuffer_Loop_1 54314 LD A,137 A=137.
54316 EX AF,AF' Exchange the AF register with the shadow AF register.
54317 LD A,B A=B.
54318 ADD A,104 A+=104.
54320 LD H,A H=A.
54321 LD L,C L=C.
54322 LD D,0 D=0.
54324 LD A,(HL) Jump to WriteSceneToShadowBuffer_Loop_3 if *HL is zero.
54325 AND A
54326 JP Z,WriteSceneToShadowBuffer_Loop_3
54329 LD (HL),D Write D to *HL.
54330 LD A,96 Write 96 to *53792.
54332 LD (53792),A
54335 DEC H Decrease H by three.
54336 DEC H
54337 DEC H
54338 LD A,(HL) Jump to WriteSceneToShadowBuffer_Loop_2 if *HL is not zero.
54339 AND A
54340 JP NZ,WriteSceneToShadowBuffer_Loop_2
54343 LD A,32 Write 32 to *53792.
54345 LD (53792),A
54348 DEC H Decrease H by three.
54349 DEC H
54350 DEC H
54351 LD A,(HL) Jump to WriteSceneToShadowBuffer_Loop_2 if *HL is not zero.
54352 AND A
54353 JP NZ,WriteSceneToShadowBuffer_Loop_2
54356 XOR A Write 0 to *53792.
54357 LD (53792),A
54360 DEC H Decrease H by three.
54361 DEC H
54362 DEC H
54363 LD A,134 A=134.
54365 EX AF,AF' Exchange the AF register with the shadow AF register.
54366 LD A,(HL) A=*HL.
WriteSceneToShadowBuffer_Loop_2 54367 AND %01111111 Keep only bits 0-6.
54369 LD E,A E=A.
54370 LD A,(HL) A=*HL.
54371 LD (53794),A Write A to *53794.
54374 LD H,D H=D.
54375 LD L,E L=E.
54376 ADD HL,HL HL*=8+DE.
54377 ADD HL,HL
54378 ADD HL,HL
54379 ADD HL,DE
54380 CP 128 Jump to WriteSceneToShadowBuffer_0 if A is higher than 128.
54382 JP NC,WriteSceneToShadowBuffer_0
54385 CALL 54504 Call 54504.
The value here is self-modified at:
Location Byte Set
54284 107
54295 115
54306 123
54388 LD D,0 D=0 (as above).
54390 LD A,(HL) A=*HL.
54391 LD (DE),A Write A to *DE.
54392 INC HL Increment HL by one.
54393 INC D Increment D by one.
54394 LD A,(HL) A=*HL.
54395 LD (DE),A Write A to *DE.
54396 INC HL Increment HL by one.
54397 INC D Increment D by one.
54398 LD A,(HL) A=*HL.
54399 LD (DE),A Write A to *DE.
54400 INC HL Increment HL by one.
54401 INC D Increment D by one.
54402 LD A,(HL) A=*HL.
54403 LD (DE),A Write A to *DE.
54404 INC HL Increment HL by one.
54405 INC D Increment D by one.
54406 LD A,(HL) A=*HL.
54407 LD (DE),A Write A to *DE.
54408 INC HL Increment HL by one.
54409 INC D Increment D by one.
54410 LD A,(HL) A=*HL.
54411 LD (DE),A Write A to *DE.
54412 INC HL Increment HL by one.
54413 INC D Increment D by one.
54414 LD A,(HL) A=*HL.
54415 LD (DE),A Write A to *DE.
54416 INC HL Increment HL by one.
54417 INC D Increment D by one.
54418 LD A,(HL) A=*HL.
54419 LD (DE),A Write A to *DE.
WriteSceneToShadowBuffer_Loop_3 54420 INC C Increment C by one.
54421 JP NZ,WriteSceneToShadowBuffer_Loop_1 Jump to WriteSceneToShadowBuffer_Loop_1 if {} is not zero.
54424 INC B Increment B by one.
54425 RET Return.
WriteSceneToShadowBuffer_0 54426 CALL 54504 Call 54504.
54429 PUSH BC Stash BC on the stack.
54430 LD A,C A=C.
54431 EXX Switch to the shadow registers.
54432 LD C,A C=A.
54433 EX AF,AF' Exchange the AF register with the shadow AF register.
54434 XOR C Reset the bits from C.
54435 AND %00000011 Keep only bits 0-1.
54437 LD C,A C=A.
54438 ADD A,A A*=8+C.
54439 ADD A,A
54440 ADD A,A
54441 ADD A,C
54442 LD B,0 B=0.
54444 LD C,A C=A.
54445 LD HL,35648 HL=35648.
54448 ADD HL,BC HL+=BC.
54449 INC L Increment L by one.
54450 PUSH HL Stash HL on the stack.
54451 EXX Switch back to the normal registers.
54452 POP BC Restore BC from the stack.
The value here is self-modified at:
Location Byte Set
54284 107
54295 115
54306 123
54453 LD D,0 D=0 (as above).
54455 LD A,(BC) A=*BC.
54456 OR (HL) Set the bits from *HL.
54457 LD (DE),A Write A to *DE.
54458 INC HL Increment HL by one.
54459 INC BC Increment BC by one.
54460 INC D Increment D by one.
54461 LD A,(BC) A=*BC.
54462 OR (HL) Set the bits from *HL.
54463 LD (DE),A Write A to *DE.
54464 INC HL Increment HL by one.
54465 INC BC Increment BC by one.
54466 INC D Increment D by one.
54467 LD A,(BC) A=*BC.
54468 OR (HL) Set the bits from *HL.
54469 LD (DE),A Write A to *DE.
54470 INC HL Increment HL by one.
54471 INC BC Increment BC by one.
54472 INC D Increment D by one.
54473 LD A,(BC) A=*BC.
54474 OR (HL) Set the bits from *HL.
54475 LD (DE),A Write A to *DE.
54476 INC HL Increment HL by one.
54477 INC BC Increment BC by one.
54478 INC D Increment D by one.
54479 LD A,(BC) A=*BC.
54480 OR (HL) Set the bits from *HL.
54481 LD (DE),A Write A to *DE.
54482 INC HL Increment HL by one.
54483 INC BC Increment BC by one.
54484 INC D Increment D by one.
54485 LD A,(BC) A=*BC.
54486 OR (HL) Set the bits from *HL.
54487 LD (DE),A Write A to *DE.
54488 INC HL Increment HL by one.
54489 INC BC Increment BC by one.
54490 INC D Increment D by one.
54491 LD A,(BC) A=*BC.
54492 OR (HL) Set the bits from *HL.
54493 LD (DE),A Write A to *DE.
54494 INC HL Increment HL by one.
54495 INC BC Increment BC by one.
54496 INC D Increment D by one.
54497 LD A,(BC) A=*BC.
54498 OR (HL) Set the bits from *HL.
54499 LD (DE),A Write A to *DE.
54500 POP BC Restore BC from the stack.
54501 JP WriteSceneToShadowBuffer_Loop_3 Jump to WriteSceneToShadowBuffer_Loop_3.
Prev: 54280 Up: Map Next: 54504