diff --git a/bin/blockloader_c8lds_ptr_tty.asm b/bin/blockloader_c8lds_ptr_tty.asm new file mode 100644 index 0000000..f103c4b --- /dev/null +++ b/bin/blockloader_c8lds_ptr_tty.asm @@ -0,0 +1,95 @@ +; 'c8lds' blockloader disassembled from chars.ptp. +; +; this loader is smart - it looks at the ROM code +; and decides if it should use PTR or TTY. + + ORG 03700 ; + +cksum equ 03677 ; store checksum just below start address + +start RCF ; 03700 0001032 + JMP patch ; 03701 0013740 ; patch loadeer to use PTR or TTY +rdblok DAC cksum ; 03702 0023677 ; AC is zero at this point +skpzer JMS rdbyte ; 03703 0037760 ; wait for non-zero byte + ASN ; 03704 0102001 + JMP skpzer ; 03705 0013703 + CIA ; 03706 0100006 + DAC wrdcnt ; 03707 0023777 ; save word count (or load address?) + JMS rdword ; 03710 0037750 ; get load address + DAC ldaddr ; 03711 0023776 + SAM eolval ; 03712 0077730 + JMP rddata ; 03713 0013715 + HLT ; 03714 0000000 +rddata JMS rdword ; 03715 0037750 + DAC *ldaddr ; 03716 0123776 + JMS updcks ; 03717 0037731 + ISZ ldaddr ; 03720 0033776 + ISZ wrdcnt ; 03721 0033777 + JMP rddata ; 03722 0013715 + JMS rdword ; 03723 0037750 + SUB cksum ; 03724 0073677 + ASN ; 03725 0102001 + JMP nxtblk ; 03726 0013746 + HLT ; 03727 0000000 + +eolval DATA 0177777 ; 03730 0177777 ;' end-of-load' load address value + +;------------------------ +; Update checksum. New word in AC. +; On exit, AC is updated checksum. +;------------------------ +updcks DATA 0 ; 03731 0017720 + CLL ; 03732 0100010 + ADD cksum ; 03733 0067677 + LSZ ; 03734 0002004 + IAC ; 03735 0100004 + DAC cksum ; 03736 0023677 + JMP *updcks ; 03737 0113731 + +;------------------------ +; Patch loader to use TTY or PTR. +;------------------------ +patch HON ; 03740 0001061 + LAC pattty ; 03741 0063774 + DAC usetty ; 03742 0023761 + LAW 01032 ; 03743 0005032 ; load RCF instruction + SAM *romflg ; 03744 0177775 ; skip if ROM is TTY (RCF @044) + DAC usetty ; 03745 0023761 ; patch this code to use PTR +nxtblk CAL ; 03746 0100011 + JMP rdblok ; 03747 0013702 + +;------------------------ +; Read a word from the input device. +;------------------------ +rdword DATA 0 ; 03750 0017711 + CAL ; 03751 0100011 + JMS rdbyte ; 03752 0037760 + RAL 3 ; 03753 0003003 + RAL 3 ; 03754 0003003 + RAL 2 ; 03755 0003002 + JMS rdbyte ; 03756 0037760 + JMP *rdword ; 03757 0113750 + +;------------------------ +; Read a byte. Patched to use TTY or PTR. +;------------------------ +rdbyte DATA 0 ; 03760 0017757 +usetty RCF ; 03761 0001032 + HSN ; 03762 0102400 + JMP .-1 ; 03763 0013762 + HSF ; 03764 0002400 + JMP .-1 ; 03765 0013764 + HRB ; 03766 0001051 + JMP *rdbyte ; 03767 0113760 + +rdtty RSF ; 03770 0002040 + JMP .-1 ; 03771 0013770 + RRC ; 03772 0001033 + JMP *rdbyte ; 03773 0113760 + +pattty JMP rdtty ; 03774 0013770 +romflg DATA 000044 ; 03775 0000044 +ldaddr DATA 000000 ; 03776 0000000 +wrdcnt DATA 000000 ; 03777 0000000 + + END ;