17 lines
591 B
Plaintext
17 lines
591 B
Plaintext
Z80_Call:
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MOVE.W #$100,$A11100 ;write: z80 reset
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.wait:
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BTST #8,$A11100 ;read: check bit 8 to see if the z80 is busy
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BNE .wait ;loop until not busy
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;now we write the function address
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;z80 is little-endian so we need to reverse the byte order.
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;also 68000 cannot safely write words at odd addresses so we need to write as bytes.
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MOVE.B #$72,$A0006D
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MOVE.B #$00,$A0006E ;this changes the "call &0000" above to "call ExampleFunction"
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MOVE.B #$FF,$A01F01 ;unlock the semaphore
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MOVE.W #0,$A11100 ;Z80 Bus Request - after this write, the Z80 will start executing code.
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