Skip to navigation

Elite on the BBC Micro and NES

Flight: DOFE21

[6502 Second Processor version, I/O processor]

Name: DOFE21 [Show more] Type: Subroutine Category: Flight Summary: Implement the #DOFE21 <flag> command (show the energy bomb effect)
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * JMPTAB calls DOFE21

This routine is run when the parasite sends a #DOFE21 <flag> command. It takes the argument and stores it in SHEILA &21 to change the palette. See p.379 of the Advanced User Guide for an explanation of palette bytes.
Arguments: A The new value of SHEILA &21
.DOFE21 STA &FE21 \ Store the new value in SHEILA &21 JMP PUTBACK \ Jump to PUTBACK to restore the USOSWRCH handler and \ return from the subroutine using a tail call