mirror of
https://github.com/rzzzwilson/pymlac.git
synced 2025-06-10 09:32:41 +00:00
77 lines
2.5 KiB
NASM
Executable File
77 lines
2.5 KiB
NASM
Executable File
; a lc16sd blockloader for TTYIN, with visual display.
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; disassembled from iasm/simpledisplay2.ptp.
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ORG 03700 ; addr code
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addr RCF ; 03700 0001032
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blkcnt JMS . ; 03701 0037701
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cksum LAC blkcnt ; 03702 0063701
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SAM hiaddr ; 03703 0077775
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JMP rdblk ; 03704 0013710
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LWC 00012 ; 03705 0104012
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DLA ; 03706 0001003
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DON ; 03707 0003100
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rdblk CAL ; 03710 0100011
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DAC cksum ; 03711 0023702 ; clear checksum
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JMS rdword ; 03712 0037746 ; get block load address
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DAC addr ; 03713 0023700
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ASP ; 03714 0002002 ; skip if positive
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JMP endtty ; 03715 0013740 ; else end-of-data
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JMS rdword ; 03716 0037746 ; get 16bit data word count
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DAC blkcnt ; 03717 0023701
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JMS rdword ; 03720 0037746 ; get checksum from TTY
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nxtwrd JMS rdword ; 03721 0037746 ; get data word
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DAC *addr ; 03722 0123700 ; store in memory
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LAC addr ; 03723 0063700 ; update display
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SAR 3 ; 03724 0003063
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AND L03765 ; 03725 0047765
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IOR L03764 ; 03726 0053764
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DAC L03766 ; 03727 0023766
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LAC *addr ; 03730 0163700
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ISZ addr ; 03731 0033700 ; bump address for next word
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ISZ blkcnt ; 03732 0033701 ; block finished?
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JMP nxtwrd ; 03733 0013721 ; if not, get next data word
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ADD cksum ; 03734 0067702
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ASZ ; 03735 0002001 ; skip if checksum OK
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JMP . ; 03736 0013736 ; if not, busy wait here
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JMP rdblk ; 03737 0013710
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;--------------------------------------
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; end of data, display off, autostart if specified
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;--------------------------------------
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endtty DOF ; 03740 0001012 ; display off
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IAC ; 03741 0100004 ;
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ASN ; 03742 0102001 ;
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HLT ; 03743 0000000 ; stop here if no autostart
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JMS rdword ; 03744 0037746 ; get AC contents
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JMP *addr ; 03745 0113700 ; goto loaded code
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;--------------------------------------
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; read a word from TTYIN, updating checksum with word in AC
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;--------------------------------------
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rdword DATA 0 ; 03746 0000000
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ADD cksum ; 03747 0067702
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DAC cksum ; 03750 0023702 ; update checksum
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CAL ; 03751 0100011
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RSF ; 03752 0002040
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JMP .-1 ; 03753 0013752 ; wait for byte available
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RRC ; 03754 0001033 ; read byte, clear flag
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RAL 3 ; 03755 0003003 ; shift byte into top of AC
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RAL 3 ; 03756 0003003
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RAL 2 ; 03757 0003002
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RSF ; 03760 0002040
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JMP .-1 ; 03761 0013760 ; wait for byte available
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RRC ; 03762 0001033 ; read into low byte of AC
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JMP *rdword ; 03763 0113746
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L03764 ; 03764 0020000
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L03765 ; 03765 0001777
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L03766 ; 03766 0020000
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; 03767 0010000
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; 03770 0004005
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; 03771 0046000
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; 03772 0021777
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; 03773 0000000
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; 03774 0067766
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hiaddr DATA 0017702 ; 03775 0017702
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; 03776 0010000
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; 03777 0177777
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END ;
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