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BBC Micro Elite

Start and end: RES2 (6502SP version)

Name: RES2 [View in context] Type: Subroutine Category: Start and end Summary: Reset a number of flight variables and workspaces
This is called after we launch from a space station, arrive in a new system after hyperspace, launch an escape pod, or die a cold, lonely death in the depths of space. Returns: Y Y is set to &FF
.RES2 LDA #NOST \ Reset NOSTM, the number of stardust particles, to the STA NOSTM \ maximum allowed (18) LDX #&FF \ Reset LSX2 and LSY2, the ball line heaps used by the STX LSX2 \ BLINE routine for drawing circles, to &FF, to set the STX LSY2 \ heap to empty STX MSTG \ Reset MSTG, the missile target, to &FF (no target) LDA #128 \ Set the current pitch rate to the mid-point, 128 STA JSTY STA ALP2 \ Reset ALP2 (roll sign) and BET2 (pitch sign) STA BET2 \ to negative, i.e. pitch and roll negative ASL A \ This sets A to 0 STA BETA \ Reset BETA (pitch angle alpha) to 0 STA BET1 \ Reset BET1 (magnitude of the pitch angle) to 0 STA ALP2+1 \ Reset ALP2+1 (flipped roll sign) and BET2+1 (flipped STA BET2+1 \ pitch sign) to positive, i.e. pitch and roll negative STA MCNT \ Reset MCNT (the main loop counter) to 0 LDA #3 \ Reset DELTA (speed) to 3 STA DELTA STA ALPHA \ Reset ALPHA (roll angle alpha) to 3 STA ALP1 \ Reset ALP1 (magnitude of roll angle alpha) to 3 LDA SSPR \ Fetch the "space station present" flag, and if we are BEQ P%+5 \ not inside the safe zone, skip the next instruction JSR SPBLB \ Light up the space station bulb on the dashboard LDA ECMA \ Fetch the E.C.M. status flag, and if E.C.M. is off, BEQ yu \ skip the next instruction JSR ECMOF \ Turn off the E.C.M. sound .yu JSR WPSHPS \ Wipe all ships from the scanner JSR ZERO \ Zero-fill pages &9, &A, &B, &C and &D, which clears \ the ship data blocks, the ship line heap, the ship \ slots for the local bubble of universe, and various \ flight and ship status variables LDA #LO(LS%) \ We have reset the ship line heap, so we now point STA SLSP \ SLSP to LS% (the byte below the ship blueprints at D%) LDA #HI(LS%) \ to indicate that the heap is empty STA SLSP+1 JSR DIALS \ Update the dashboard \ Finally, fall through into ZINF to reset the INWK \ ship workspace