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⌂ ∞ ▽ Elite on the BBC Micro and NES

Loader: TestPro

[BBC Micro disc version, Sideways RAM Loader]

       Name: TestPro                                                 [Show more]
       Type: Subroutine
   Category: Loader
    Summary: Test whether we are running this on a co-processor

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * testpro% calls TestPro




.TestPro

 LDA #0                 \ If this is a co-processor, then the DEC A instruction
 DEC A                  \ will be supported and will decrement A to &FF, but if
                        \ this is not a co-processor, the DEC A instruction will
                        \ have no effect

 STA proflag%           \ Set proflag% to A, which will be &FF if this is a
                        \ co-processor, 0 otherwise

 RTS                    \ Return from the subroutine