52 lines
743 B
ArmAsm
52 lines
743 B
ArmAsm
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//
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// RS-232 part of the OPEN routine
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//
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#if HAS_RS232
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#if CONFIG_MEMORY_MODEL_60K
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.error "CONFIG_MEMORY_MODEL_60K is not compatible with RS-232 memory allocation code"
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#endif
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open_rs232:
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// First check how many RS-232 channels are currently allocated.
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// If more than one, skip allocation (already allocated).
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jsr rs232_count_channels
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bcs open_rs232_end
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// Allocate buffers - first RIBUF, afterwards ROBUF
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// (checked addresses on original ROMs)
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lda MEMSIZK+0
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sta ROBUF+0
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sta RIBUF+0
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dec MEMSIZK+1
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lda MEMSIZK+1
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sta RIBUF+1
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dec MEMSIZK+1
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lda MEMSIZK+1
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sta ROBUF+1
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// Initialize buffer indexes
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lda #$00
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sta RIDBE
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sta RIDBS
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sta RODBS
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sta RODBE
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open_rs232_end:
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jmp open_done_success
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#endif // HAS_RS232
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