From f653649bce7ea3ac26771451bc910eaa1a1e1d1a Mon Sep 17 00:00:00 2001
From: Ross Wilson <rzzzwilson@gmail.com>
Date: Sat, 12 Mar 2016 11:04:48 +0700
Subject: [PATCH] Replace old c8lds blockloader with ambidextrous

---
 pyasm/pyasm | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 103 insertions(+), 1 deletion(-)

diff --git a/pyasm/pyasm b/pyasm/pyasm
index aca097a..fdd6ffc 100755
--- a/pyasm/pyasm
+++ b/pyasm/pyasm
@@ -221,7 +221,7 @@ OpcodeData = {
 # The papertape/teletype loader code (c8lds form)
 ######
 
-BlockLoader_C8LDS = [
+X_BlockLoader_C8LDS = [
 #     code     address  assembler source code
 #    -------   -------  ------------------------------------------------------------------------
               #        ; Imlac Papertape Program Block Loader
@@ -419,6 +419,108 @@ BlockLoader_LC16SD = [
               #                END             ;
               ]
 
+
+BlockLoader_C8LDS = [
+         #        0001: ; 'c8lds' blockloader disassembled from chars.ptp.
+         #        0002: ;
+         #        0003: ; this loader is smart - it looks at the ROM code
+         #        0004: ; and decides if it should use PTR or TTY.
+         #        0005: 
+         #03700   0006:         ORG     03700   ;
+         #        0007: 
+         #03677   0008: cksum   equ     03677   ; store checksum just below start address
+         #        0009: 
+0001032, #03700   0010: start	RCF		; 03700 0001032
+0013740, #03701   0011: 	JMP	patch	; 03701 0013740 ; patch loadeer to use PTR or TTY
+0023677, #03702   0012: rdblok	DAC	cksum	; 03702 0023677 ; AC is zero at this point
+0037760, #03703   0013: skpzer	JMS	rdbyte	; 03703 0037760 ; wait for non-zero byte
+0102001, #03704   0014: 	ASN		; 03704 0102001
+0013703, #03705   0015: 	JMP	skpzer	; 03705 0013703
+0100006, #03706   0016: 	CIA		; 03706 0100006
+0023777, #03707   0017: 	DAC	wrdcnt	; 03707 0023777 ; save word count (or load address?)
+0037750, #03710   0018: 	JMS	rdword	; 03710 0037750 ; get load address
+0023776, #03711   0019: 	DAC	ldaddr	; 03711 0023776
+0077730, #03712   0020: 	SAM	eolval	; 03712 0077730
+0013715, #03713   0021: 	JMP	rddata	; 03713 0013715
+0000000, #03714   0022: 	HLT		; 03714 0000000
+0037750, #03715   0023: rddata	JMS	rdword	; 03715 0037750
+0123776, #03716   0024: 	DAC	*ldaddr	; 03716 0123776
+0037731, #03717   0025: 	JMS	updcks	; 03717 0037731
+0033776, #03720   0026: 	ISZ	ldaddr	; 03720 0033776
+0033777, #03721   0027: 	ISZ	wrdcnt	; 03721 0033777
+0013715, #03722   0028: 	JMP	rddata	; 03722 0013715
+0037750, #03723   0029: 	JMS	rdword	; 03723 0037750
+0073677, #03724   0030: 	SUB	cksum	; 03724 0073677
+0102001, #03725   0031: 	ASN		; 03725 0102001
+0013746, #03726   0032: 	JMP	nxtblk	; 03726 0013746
+0000000, #03727   0033: 	HLT		; 03727 0000000
+         #        0034: 
+0177777, #03730   0035: eolval	DATA	0177777	; 03730 0177777 ;' end-of-load' load address value
+         #        0036: 
+         #        0037: ;------------------------
+         #        0038: ; Update checksum.  New word in AC.
+         #        0039: ; On exit, AC is updated checksum.
+         #        0040: ;------------------------
+0000000, #03731   0041: updcks	DATA	0	; 03731 0017720
+0100010, #03732   0042: 	CLL		; 03732 0100010
+0067677, #03733   0043: 	ADD	cksum	; 03733 0067677
+0002004, #03734   0044: 	LSZ		; 03734 0002004
+0100004, #03735   0045: 	IAC		; 03735 0100004
+0023677, #03736   0046: 	DAC	cksum	; 03736 0023677
+0113731, #03737   0047: 	JMP	*updcks	; 03737 0113731
+         #        0048: 
+         #        0049: ;------------------------
+         #        0050: ; Patch loader to use TTY or PTR.
+         #        0051: ;------------------------
+0001061, #03740   0052: patch	HON		; 03740 0001061
+0063774, #03741   0053: 	LAC	pattty	; 03741 0063774
+0023761, #03742   0054: 	DAC	usetty	; 03742 0023761
+0005032, #03743   0055: 	LAW	01032	; 03743 0005032 ; load RCF instruction
+0177775, #03744   0056: 	SAM	*romflg	; 03744 0177775 ; skip if ROM is TTY (RCF @044)
+0023761, #03745   0057: 	DAC	usetty	; 03745 0023761 ; patch this code to use PTR
+0100011, #03746   0058: nxtblk	CAL		; 03746 0100011
+0013702, #03747   0059: 	JMP	rdblok	; 03747 0013702
+         #        0060: 
+         #        0061: ;------------------------
+         #        0062: ; Read a word from the input device.
+         #        0063: ;------------------------
+0000000, #03750   0064: rdword	DATA	0	; 03750 0017711
+0100011, #03751   0065: 	CAL		; 03751 0100011
+0037760, #03752   0066: 	JMS	rdbyte	; 03752 0037760
+0003003, #03753   0067: 	RAL	3	; 03753 0003003
+0003003, #03754   0068: 	RAL	3	; 03754 0003003
+0003002, #03755   0069: 	RAL	2	; 03755 0003002
+0037760, #03756   0070: 	JMS	rdbyte	; 03756 0037760
+0113750, #03757   0071: 	JMP	*rdword	; 03757 0113750
+         #        0072: 
+         #        0073: ;------------------------
+         #        0074: ; Read a byte.  Patched to use TTY or PTR.
+         #        0075: ;------------------------
+0000000, #03760   0076: rdbyte	DATA	0	; 03760 0017757
+0001032, #03761   0077: usetty	RCF		; 03761 0001032
+0102400, #03762   0078: 	HSN		; 03762 0102400
+0013762, #03763   0079: 	JMP	.-1	; 03763 0013762
+0002400, #03764   0080: 	HSF		; 03764 0002400
+0013764, #03765   0081: 	JMP	.-1	; 03765 0013764
+0001051, #03766   0082: 	HRB		; 03766 0001051
+0113760, #03767   0083: 	JMP	*rdbyte	; 03767 0113760
+         #        0084: 
+0002040, #03770   0085: rdtty	RSF		; 03770 0002040
+0013770, #03771   0086: 	JMP	.-1	; 03771 0013770
+0001033, #03772   0087: 	RRC		; 03772 0001033
+0113760, #03773   0088: 	JMP	*rdbyte	; 03773 0113760
+         #        0089: 
+0013770, #03774   0090: pattty	JMP	rdtty	; 03774 0013770
+0000044, #03775   0091: romflg	DATA	000044	; 03775 0000044
+0000000, #03776   0092: ldaddr	DATA	000000	; 03776 0000000
+0000000, #03777   0093: wrdcnt	DATA	000000	; 03777 0000000
+         #        0094: 
+         #        0095: 	END		;
+                    ]
+
+
+
+
 def usage(msg=None):
     """Print usage and optional error message."""