127 lines
2.7 KiB
ArmAsm
127 lines
2.7 KiB
ArmAsm
cmd_load:
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// Parse filename
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// (we can tell the KERNAL where it is in memory directly, since the
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// KERNAL will be able to peek under ROMs to read it, since it will have
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// to be able to peek under the ROMs for SAVE and VERIFY).
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// Parse optional device #
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// Parse optional secondary address
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// XXX - C64 BASIC apparently doesn't clear variables after a LOAD in the
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// middle of a program. For safety, we do.
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jsr basic_do_clr
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// Set filename and length
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lda #$00
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sta FNLEN
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// Without tape support, LOAD must have a filename
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// (This also skips any leading spaces)
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jsr basic_end_of_statement_check
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bcc !+
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jmp do_MISSING_FILENAME_error
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!:
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jsr basic_fetch_and_consume_character
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cmp #$22
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beq !+
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jmp do_SYNTAX_error
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!:
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// Filename starts here so set pointer
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lda TXTPTR+0
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sta FNADDR+0
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lda TXTPTR+1
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sta FNADDR+1
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// Now search for end of line or closing quote
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// so that we know the length of the filename
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getting_filename:
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jsr basic_fetch_and_consume_character
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cmp #$22
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beq got_filename
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cmp #$00
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bne !+
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jsr basic_unconsume_character
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jmp got_filename
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!:
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inc FNLEN
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jmp getting_filename
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got_filename:
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// Now fetch the file number, start from the default one
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jsr select_device
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stx FA
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jsr injest_comma
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bcs got_devicenumber
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jsr basic_parse_line_number
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lda LINNUM+1
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beq !+
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jmp do_ILLEGAL_QUANTITY_error
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!:
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lda LINNUM+0
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sta FA
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got_devicenumber:
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// Now fetch the secondary address
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lda #$00
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sta SA
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jsr injest_comma
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bcs got_secondaryaddress
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jsr basic_parse_line_number
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lda LINNUM+1
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bne !+
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lda LINNUM+0
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sta SA
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jmp got_secondaryaddress
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!:
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// Second parameter is above 255, this can't be a secondary address
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// Use it as load address instead
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// XXX temporary syntax, it would be better to use something
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// XXX like 'LOAD"FILE",8 TO 49152'
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ldx LINNUM+0
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ldy LINNUM+1
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bne got_loadaddress
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got_secondaryaddress:
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ldy TXTTAB+1
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ldx TXTTAB+0
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got_loadaddress:
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lda #$00 // LOAD not verify
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jsr JLOAD
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php
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pha
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jsr print_return
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pla
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plp
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bcc !+
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// A = KERNAL error code, which also almost match
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// basic ERROR codes, so we can just copy the
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// error code to X, decrement, and handle normally
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tax
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dex
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jmp do_basic_error
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!:
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// $YYXX is the last loaded address, so store it
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stx VARTAB+0
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sty VARTAB+1
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// Now relink the loaded program, as we cannot trust the line
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// links supplied. For example, the VICE virtual drive emulation
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// always supplies $0101 as the address of the next line.
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jsr LINKPRG
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// After LOADing, we either start the program from the beginning,
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// or go back to the READY prompt if LOAD was called from direct mode.
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// Reset to start of program
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jsr init_oldtxt
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// XXX - should run program if LOAD was used in program mode
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jmp basic_main_loop
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