44 lines
827 B
NASM
44 lines
827 B
NASM
case on
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GSOSBusy gequ $E100BE
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INSTALL_DRIVER gequ $01FCA8
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dummy private
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end
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* Adapted from procedure shown in Brutal Deluxe GS/OS Internals book
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InstallDriver start
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phb ; set data bank to $E1 (to access GSOSBusy)
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pea $E1E1
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plb
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plb
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lda #$8000 ; check and set GS/OS busy flag
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tsb |GSOSBusy
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bne exit ; bail out if GS/OS is busy
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phd
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lda >gsosDP ; set DP to GS/OS direct page
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tcd ; (should be unnecessary for INSTALL_DRIVER)
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jsl ForceLCBank1 ; force in language card bank 1
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pha ; save old state reg
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ldx #dibList
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ldy #^dibList
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jsl INSTALL_DRIVER ; install the driver
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tcd ; save INSTALL_DRIVER result
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jsl RestoreStateReg ; restore old state reg
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lda #$8000 ; clear GS/OS busy flag
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trb |GSOSBusy
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tdc ; return INSTALL_DRIVER result
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pld ; restore direct page
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exit plb
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rtl
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end
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