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Tactics: FRMIS

[Acorn Electron version]

Name: FRMIS [Show more] Type: Subroutine Category: Tactics Summary: Fire a missile from our ship
Context: See this subroutine in context in the source code Variations: See code variations for this subroutine in the different versions References: This subroutine is called as follows: * Main flight loop (Part 3 of 16) calls FRMIS

We fired a missile, so send it streaking away from us to unleash mayhem and destruction on our sworn enemies.
.FRMIS LDX #MSL \ Call FRS1 to launch a missile straight ahead of us JSR FRS1 BCC FR1 \ If FRS1 returns with the C flag clear, then there \ isn't room in the universe for our missile, so jump \ down to FR1 to display a "missile jammed" message LDX MSTG \ Fetch the slot number of the missile's target JSR GINF \ Get the address of the data block for the target ship \ and store it in INF LDA FRIN,X \ Fetch the ship type of the missile's target into A JSR ANGRY \ Call ANGRY to make the target ship hostile LDY #&04 \ We have just launched a missile, so we need to remove JSR ABORT \ missile lock and hide the leftmost indicator on the \ dashboard by setting it to black (Y = &04) DEC NOMSL \ Reduce the number of missiles we have by 1 LDA #48 \ Call the NOISE routine with A = 48 to make the sound JMP NOISE \ of a missile launch, returning from the subroutine \ using a tail call