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BBC Micro Elite

Tactics: SFRMIS (6502SP version)

Name: SFRMIS [View in context] Type: Subroutine Category: Tactics Summary: Add an enemy missile to our local bubble of universe
An enemy has fired a missile, so add the missile to our universe if there is room, and if there is, make the appropriate warnings and noises.
.SFRMIS LDX #MSL \ Set X to the ship type of a missile, and call SFS1-2 JSR SFS1-2 \ to add the missile to our universe with an AI flag \ of %11111110 (AI enabled, hostile, no E.C.M.) BCC KYTB \ The C flag will be set if the call to SFS1-2 was a \ success, so if it's clear, jump to KYTB to return from \ the subroutine (as KYTB contains an RTS) LDA #120 \ Print recursive token 120 ("INCOMING MISSILE") as an JSR MESS \ in-flight message LDA #48 \ Call the NOISE routine with A = 48 to make the sound BNE NOISE \ of the missile being launched and return from the \ subroutine using a tail call (this BNE is effectively \ a JMP as A will never be zero)