Subject: /bin/as - major changes (#153 - part 2 of 2)
Index:	bin/as/* 2.11BSD

Description:
	This is part 2 (of 2) of changes and improvements to the
	assembler.  This description and the directions for applying
	the update are repeated in both parts of the update kit.

	The changes include:

	1) Consolidation of the assembler source into 2 source files
	   rather than 18 (some of which were empty/null!) files.

	2) Elimination of 2 of the 3 /tmp files.  Previously 'as' created
	   3 files in /tmp:

		a) /tmp/atm1aXXXXXX - the intermediate object file

		b) /tmp/atm2aXXXXXX - the forward/backward (fb) branch table

		c) /tmp/atm3aXXXXXX - the symbol table

	   Only the first file is used now because the 'fb' and symbol
	   tables are maintained in memory only.

	3) Elimination of /lib/as2!  /bin/as now contains _both_ phases of
	   the assembler.  There is no 'exec' of a second program now.  Not
	   having a second program also means that the symbol table does
	   not need to be written out by /bin/as and then read by /lib/as2.

	4) The filename '-' can be used to read input from the "stdin".  

	5) Support for the "string table" (a la 4.3BSD) object file format 
	   (long symbol names).  The new assembler can produce _either_ the 
	   old "fixed 8" symbol table information or the new variable length 
	   "string table" format.  
	   
	   The default is the _old style_ (obviously) but the choice of 
	   symbol table output format is a simple true/false (patchable
	   via 'adb') flag.

Repeat-By:
	By observation and experience.  The organization of 'as' (items 1,2 and
	3) has always left much to be desired.  Number 4 is a nicety added
	at the last moment.

	Long symbol names (a cap of 32 characters is used to avoid running
	out of space) have been missing for long enough!  With the assembler
	done only 'ld', 'ranlib', 'nlist(3)' and a few miscellaneous 
	utilities need to be rewritten/modified.  The changes to 'ld' are
	being sketched out on paper now.  Time permitting the new symbol
	table format will be done on or before Christmas.

Fix:
	MAKE SURE you have both parts 1 and 2 of this update kit!

	Part 2 (this part) includes the patches for 'as2.s' (the last 
	pass of the assembler.

	++++++++Description of changes+++++++++

	The detailed directions for installing the assembler updates follow
	this description of what changes were made.  I may have overlooked
	a couple of the smaller/cosmetic changes but those are obvious
	by looking at the sources.

	1) All of the as1?.s files have been catenated into as0.s and the
	   as2?.s files have been catenated into as2.s.

	2) as0.s and as2.s have some of the same symbols, therefore all
	   symbols must be _explicitly_ made global with the .globl, the
	   old practice of using the '-' or '-g' option can not and must
	   not be used.

	3) The replicated initialization code in as2 has been removed.
	   Because the symbol table is already in memory there is no
	   need to read it in.  Similarily the intermediate object file
	   is already open, it merely needs to be rewound rather than
	   reopened.

	4) There is only _1_ Permanent Symbol Table (PST) now, the 
	   "duplicate" copies (one for /bin/as and another for /lib/as2)
	   have been merged into a single table.  In order to use a 
	   similar symbol table format for the PST and UST (User Symbol
	   Table) the layout of the PST was altered - the strings are
	   no longer embedded in the PST.  A macro capability would have
	   made this easier, but...

	5) Symbol tables are extended by using either _realloc (in the
	   case of the 'fb' table since it is never very large) or by
	   linked blocks of memory created by _calloc.  The old practice
	   of simply calling _sbrk is not used (it meant that only the
	   _last_ table could be expanded.  Ugghh.)

	6) The 'string' part of a UST entry is allocated separately from
	   the value+flags data of a symbol.

	7) A temporary file for the 'fb' table is no longer used.  Instead
	   a realloc()'d table is used.  It should be noted that C files
	   processed by /lib/c2 very _rarely_ have a 'fb' table longer
	   than 0 bytes (because 'c2' is very good at rearranging branches).

	8) Fairly large blocks of (helpful it is hoped) comments were
	   included in the new sections of code.  The tab'ing was made
	   more uniform in other areas of the code.

	9) The data and buffer declarations were consolidated at the
	   end of each source file rather than being scattered thru the
	   modules.

	10) The hashtable is dynamically allocated rather than being
	    statically declared.

	11) Code was added in as2 to output either the old or new style
	    of symbol table entry to the a.out file.  If the global
	    variable 'Newsym' is 0 the old style is output (this is
	    the default) otherwise the new format is emitted.

	++++++++End of Description of changes+++++++++

	---------------------start of installation instructions------------
	Save the indicated portion of this file to /tmp/152.  Do a similar
	thing to part 2 (patch #153) - saving the patch portion to /tmp/153.

	BACK UP THE CURRENT ASSEMBLER!  Unless you're very trusting or
	very forgiving you will want to back up both the current executables
	for the assembler:

		tar cf safe_place.tar /bin/as /lib/as2

	THEN:

		cd /usr/src/bin
		mv as as.old
		mkdir as
		chmod 755 as
		cd as
		cp ../as.old/Makefile Makefile
		cat ../as.old/as1?.s > as0.s
		cat ../as.old/as2?.s > as2.s
		patch < /tmp/152
		patch < /tmp/153
		make
		make install
		make clean
		make
		make install

	The double 'make' at the end makes sure that the new assembler
	can rebuild itself.

	If for any reason the patches do not apply cleanly or the
	assembler can not rebuild itself:

		tar -xpvf safe_place

	to restore the old versions.  Then send me a mail item and I will
	send a complete dropin replacement for 'as'.

==============================cut here===============================
*** /usr/src/bin/as/as2.s.old	Tue Sep 14 19:28:29 1993
--- /usr/src/bin/as/as2.s	Wed Sep  1 19:26:36 1993
***************
*** 1,112 ****
! /
! /
  
! / a21 -- pdp-11 assembler pass 2 
! 
! .data
! .globl _environ				/ for the standard library
! _environ: 0
! .text
! 
! .globl	_main
! _main:
! 	mov	$1,-(sp)		/ signal(SIGINT, SIG_IGN)
! 	mov	$2,-(sp)		/	sys	signal; 2; 1
! 	jsr	pc,_signal
! 	cmp	(sp)+,(sp)+
! 
! 	ror	r0
! 	bcs	1f
! 
! 	mov	$saexit,-(sp)		/ signal(SIGINT, saexit)
! 	mov	$2,-(sp)		/	sys	signal; 2; saexit
! 	jsr	pc,_signal
! 	cmp	(sp)+,(sp)+
  1:
- 	jmp	start
  
! / set up sizes and origins
  
! go:
! 
! / read in symbol table
! 
! 	mov	usymtab,r1
  1:
! 	jsr	pc,getw
! 	bvs	1f
! 	add	$14,symsiz		/ count symbols
! 	jsr	pc,getw
! 	jsr	pc,getw
! 	jsr	pc,getw
! 	jsr	pc,getw
! 	mov	r4,r0
  	bic	$!37,r0
  	cmp	r0,$2			/text
  	blo	2f
  	cmp	r0,$3			/data
  	bhi	2f
! 	add	$31,r4			/mark "estimated"
! 	mov	r4,(r1)+
! 	jsr	pc,getw
! 	mov	r4,(r1)+
  	br	3f
  2:
  	clr	(r1)+
  	clr	(r1)+
- 	jsr	pc,getw
  3:
! 	jsr	pc,setbrk
! 	br	1b
  1:
  
! / read in f-b definitions
  
! 	mov	r1,fbbufp
! 	mov	fbfil,fin
! 	clr	ibufc
  1:
! 	jsr	pc,getw
! 	bvs	1f
  	add	$31,r4			/ "estimated"
  	mov	r4,(r1)+
! 	jsr	pc,getw
! 	mov	r4,(r1)+
! 	jsr	pc,setbrk
  	br	1b
! 1:
  	mov	r1,endtable
  	mov	$100000,(r1)+
  
! / set up input text file; initialize f-b table
  
! 	jsr	pc,setup
! / do pass 1
  
- 	jsr	pc,assem
- 
  / prepare for pass 2
  	cmp	outmod,$777
  	beq	1f
  	jmp	aexit
  1:
- 	clr	dot
- 	mov	$2,dotrel
- 	mov	$..,dotdot
- 	clr	brtabp
- 
- 	mov	r1,-(sp)		/ protect r1 from library
- 	mov	fin,-(sp)		/ close(fin)
- 	jsr	pc,_close		/	movb	fin,r0
- 	tst	(sp)+			/	sys	close
- 	mov	(sp)+,r1
- 
- 	mov	a.tmp1,-(sp)
- 	jsr	pc,ofile
- 	mov	r0,fin
- 	clr	ibufc
  	jsr	pc,setup
- 	inc	passno
  	inc	bsssiz
  	bic	$1,bsssiz
  	mov	txtsiz,r1
--- 1,117 ----
! 	.globl	_signal, _close, _lseek, _unlink, _umask, _chmod, __exit
! 	.globl	_write, _read, _brk, _end, _open, _creat, _realloc, _fchmod
! 	.globl	pass1, hshsiz, outmod, dot, dotdot, error
! 	.globl	checkeos, curfb, savdot, ch, line, savop, inbuf, errflg
! 	.globl	fbptr, fbtbl, symnum, hshtab, symblk, symleft, dotrel
! 	.globl	symtab, aexit, overlaid, defund, a.outp, passno, filerr
! 	.globl	wrterr, argb, errore, errora, curfb, nxtfb, usymtab
! 	.globl	fin, fout, a.tmp1, ibufc, ibufp, obufp, outbuf, symbol
! 	.globl	PSTENTSZ, SYMENTSZ, SYMBLKSZ, Newsym
  
! pass1:
! 	mov	fout,fin		/ tmp file is now input file
! 	mov	$666,-(sp)		/ mode
! 	mov	$3001 ,-(sp)		/ O_WRONLY|O_CREAT|O_TRUNC
! 	mov	a.outp,-(sp)		/ filename
! 	jsr	pc,_open
! 	add	$6,sp
! 	mov	r0,fout			/ file descriptor any good?
! 	bpl	1f			/ yes - br
! 	mov	a.outp,-(sp)
! 	jsr	pc,filerr
  1:
  
! / 'symnum' has number of symbols.  The hashtable from pass 0 is no
! / longer needed - we can reuse it directly for 'usymtab' if there are less 
! / than 'hshsiz' symbols.  If there are more than 'hshsiz' (currently
! / 1500) symbols we have to realloc.
! /
! / The 'fb' table (usually 0 long) is appended to the 'usymtab' (4 byte
! / entries per symbol).
  
! 	mov	fbptr,r0
! 	sub	fbtbl,r0		/ # bytes in 'fb' table
! 	asr	r0			/ convert to number of words
! 	add	symnum,r0		/ add in number of symbols twice
! 	add	symnum,r0		/ because we need 2 words per symbol
! 	inc	r0			/ one more for terminator word
! 	cmp	r0,$hshsiz		/ is hashtable big enough already?
! 	blo	1f			/ yes -br
! 	asl	r0			/ convert to bytes
! 	mov	r0,-(sp)
! 	mov	hshtab,-(sp)
! 	jsr	pc,_realloc		/ hshtab = realloc(hshtab, r0)
! 	mov	r0,hshtab
! 	/ check for failure?
  1:
! 	mov	hshtab,r1
! 	mov	usymtab,r2
! 9:
! 	mov	r2,symblk		/ save ptr to start of block
! 	tst	(r2)+			/ skip link word
! 	mov	$SYMBLKSZ,symleft	/ init amount left in block
! 1:
! 	tst	(r2)			/ end of symbol table block
! 	beq	4f			/ yes - br
! 	add	$8.,symsiz		/ size of symbol table
! 	tst	Newsym			/ are we doing new style?
! 	bne	8f			/ yes - br
! 	add	$4,symsiz		/ no, symbol table entries are bigger
! 8:
! 	mov	2(r2),r0		/ flags word
  	bic	$!37,r0
  	cmp	r0,$2			/text
  	blo	2f
  	cmp	r0,$3			/data
  	bhi	2f
! 	add	$31,r0			/mark "estimated"
! 	mov	r0,(r1)+		/ store flags word
! 	mov	4(r2),(r1)+		/ copy value word
  	br	3f
  2:
  	clr	(r1)+
  	clr	(r1)+
  3:
! 	add	$SYMENTSZ,r2		/ skip to next symbol entry
! 	sub	$SYMENTSZ,symleft	/ one symbol less in block
! 	cmp	symleft,$SYMENTSZ	/ room for another symbol?
! 	bge	1b			/ yes - br
! 4:
! 	mov	*symblk,r2		/ follow link to next block
! 	bne	9b			/ if not at end
  1:
  
! / The 'fb' table needs to be appended to the 'usymtab' table now
  
! 	mov	fbtbl,r0
! 	mov	r1,fbbufp		/ save start of 'fb' table
  1:
! 	cmp	r0,fbptr		/ at end of table?
! 	bhis	2f			/ yes - br
! 	mov	(r0)+,r4
  	add	$31,r4			/ "estimated"
  	mov	r4,(r1)+
! 	mov	(r0)+,(r1)+
  	br	1b
! 2:
  	mov	r1,endtable
  	mov	$100000,(r1)+
  
! 	mov	$savdot,r0		/ reset the 'psect' (text,data,bss)
! 	clr	(r0)+			/ counters for the next pass
! 	clr	(r0)+
! 	clr	(r0)+
! 	jsr	pc,setup		/ init fb stuff
  
! 	jsr	pc,pass1_2		/ do pass 1
  
  / prepare for pass 2
+ 	inc	passno
  	cmp	outmod,$777
  	beq	1f
  	jmp	aexit
  1:
  	jsr	pc,setup
  	inc	bsssiz
  	bic	$1,bsssiz
  	mov	txtsiz,r1
***************
*** 118,127 ****
  	bic	$1,r2
  	mov	r2,datsiz
  	mov	r1,r3
! 	mov	r3,datbase	/ txtsiz
  	mov	r3,savdot+2
  	add	r2,r3
! 	mov	r3,bssbase	/ txtsiz+datsiz
  	mov	r3,savdot+4
  	clr	r0
  	asl	r3
--- 123,132 ----
  	bic	$1,r2
  	mov	r2,datsiz
  	mov	r1,r3
! 	mov	r3,datbase		/ txtsiz
  	mov	r3,savdot+2
  	add	r2,r3
! 	mov	r3,bssbase		/ txtsiz+datsiz
  	mov	r3,savdot+4
  	clr	r0
  	asl	r3
***************
*** 128,148 ****
  	adc	r0
  	add	$20,r3
  	adc	r0
! 	mov	r3,symseek+2	/ 2*txtsiz+2*datsiz+20
  	mov	r0,symseek
  	sub	r2,r3
  	sbc	r0
! 	mov	r3,drelseek+2	/ 2*txtsiz+datsiz
  	mov	r0,drelseek
  	sub	r1,r3
  	sbc	r0
! 	mov	r3,trelseek+2	/ txtsiz+datsiz+20
  	mov	r0,trelseek
  	sub	r2,r3
  	sbc	r0
  	mov	r0,datseek
! 	mov	r3,datseek+2	/ txtsiz+20
! 	mov	usymtab,r1
  1:
  	jsr	pc,doreloc
  	add	$4,r1
--- 133,153 ----
  	adc	r0
  	add	$20,r3
  	adc	r0
! 	mov	r3,symseek+2		/ 2*txtsiz+2*datsiz+20
  	mov	r0,symseek
  	sub	r2,r3
  	sbc	r0
! 	mov	r3,drelseek+2		/ 2*txtsiz+datsiz
  	mov	r0,drelseek
  	sub	r1,r3
  	sbc	r0
! 	mov	r3,trelseek+2		/ txtsiz+datsiz+20
  	mov	r0,trelseek
  	sub	r2,r3
  	sbc	r0
  	mov	r0,datseek
! 	mov	r3,datseek+2		/ txtsiz+20
! 	mov	hshtab,r1
  1:
  	jsr	pc,doreloc
  	add	$4,r1
***************
*** 162,171 ****
  	mov	(r1)+,r0
  	mov	$txtp,-(sp)
  	jsr	pc,putw
! 	dec	r2
! 	bne	1b
! 	jsr	pc,assem
  
  /polish off text and relocation
  
  	mov	$txtp,-(sp)
--- 167,176 ----
  	mov	(r1)+,r0
  	mov	$txtp,-(sp)
  	jsr	pc,putw
! 	sob	r2,1b
  
+ 	jsr	pc,pass1_2			/ do pass 2
+ 
  /polish off text and relocation
  
  	mov	$txtp,-(sp)
***************
*** 174,257 ****
  	jsr	pc,flush
  
  / append full symbol table
- 
- 	mov	symf,r0
- 	mov	r0,fin
- 
- 	clr	-(sp)			/ lseek(fin, 0L, L_SET)
- 	clr	-(sp)			/	sys	lseek; 0; 0; 0
- 	clr	-(sp)
- 	mov	r0,-(sp)
- 	jsr	pc,_lseek
- 	add	$8.,sp
- 
- 	clr	ibufc
  	mov	symseek,r0
  	mov	symseek+2,r1
  	mov	$txtp,-(sp)
  	jsr	pc,oset
! 	mov	usymtab,r1
! 1:
! 	jsr	pc,getw
! 	bvs	1f
! 	mov	r4,r0
  	mov	$txtp,-(sp)
- 	jsr	pc,putw
- 	jsr	pc,getw
- 	mov	r4,r0
- 	mov	$txtp,-(sp)
- 	jsr	pc,putw
- 	jsr	pc,getw
- 	mov	r4,r0
- 	mov	$txtp,-(sp)
- 	jsr	pc,putw
- 	jsr	pc,getw
- 	mov	r4,r0
- 	mov	$txtp,-(sp)
- 	jsr	pc,putw
- 	mov	(r1)+,r0
- 	mov	$txtp,-(sp)
- 	jsr	pc,putw
- 	mov	(r1)+,r0
- 	mov	$txtp,-(sp)
- 	jsr	pc,putw
- 	jsr	pc,getw
- 	jsr	pc,getw
- 	br	1b
- 1:
- 	mov	$txtp,-(sp)
  	jsr	pc,flush
! 	jmp	aexit
  
  saexit:
  	mov	pc,errflg
  
  aexit:
! 	mov	a.tmp1,-(sp)		/ unlink(a.tmp1)
! 	jsr	pc,_unlink		/	mov	a.tmp1,0f
! 					/	sys	unlink; 0:..
! 	mov	a.tmp2,(sp)		/ unlink(a.tmp2)
! 	jsr	pc,_unlink		/	mov	a.tmp2,0f
! 					/	sys	unlink; 0:..
! 	mov	a.tmp3,(sp)		/ unlink(a.tmp3)
! 	jsr	pc,_unlink		/	mov	a.tmp3,0f
! 					/	sys	unlink; 0:..
  	tst	errflg
! 	jne	2f
  
! 	clr	(sp)			/ umask(0)
! 	jsr	pc,_umask		/	sys	umask; 0
  
! 	bic	r0,outmod		/ chmod(a.outp2, outmod&umask(0))
! 	mov	outmod,(sp)		/	bic	r0,outmod
! 	mov	a.outp2,-(sp)		/	sys	chmod; a.outp2:a.out; outmod: 777
! 	jsr	pc,_chmod
  	tst	(sp)+
- .data
- a.outp2:	a.out
- outmod:		0777
- .text
- 
  	clr	(sp)
  	br	1f
  2:
--- 179,220 ----
  	jsr	pc,flush
  
  / append full symbol table
  	mov	symseek,r0
  	mov	symseek+2,r1
  	mov	$txtp,-(sp)
  	jsr	pc,oset
! 
! 	mov	usymtab,r2		/ pointer to first symbol block
! 	mov	hshtab,r1		/ 'type' and 'value' array
! 
! 	tst	Newsym
! 	beq	8f
! 	jsr	pc,nsymout
! 	br	9f
! 8:
! 	jsr	pc,osymout
! 9:
  	mov	$txtp,-(sp)
  	jsr	pc,flush
! 	br	aexit
  
  saexit:
  	mov	pc,errflg
  
  aexit:
! 	mov	$a.tmp1,-(sp)		/ unlink(a.tmp1)
! 	jsr	pc,_unlink
  	tst	errflg
! 	bne	2f
  
! 	clr	(sp)
! 	jsr	pc,_umask
  
! 	bic	r0,outmod		/ fchmod(fout, outmod&umask(0))
! 	mov	outmod,(sp)
! 	mov	fout,-(sp)
! 	jsr	pc,_fchmod
  	tst	(sp)+
  	clr	(sp)
  	br	1f
  2:
***************
*** 258,264 ****
  	mov	$2,(sp)
  1:
  	jsr	pc,__exit		/ _exit(errflg ? 2 : 0)
! 					/	sys	exit
  filerr:
  	mov	2(sp),r0		/ filename string.  no need to clean
  	tst	-(sp)			/ stack, this routine goes to saexit.
--- 221,227 ----
  	mov	$2,(sp)
  1:
  	jsr	pc,__exit		/ _exit(errflg ? 2 : 0)
! 
  filerr:
  	mov	2(sp),r0		/ filename string.  no need to clean
  	tst	-(sp)			/ stack, this routine goes to saexit.
***************
*** 278,285 ****
  	mov	$1,-(sp)
  	jsr	pc,_write
  	add	$6,sp
! 	jmp	saexit
  
  doreloc:
  	movb	(r1),r0
  	bne	1f
--- 241,388 ----
  	mov	$1,-(sp)
  	jsr	pc,_write
  	add	$6,sp
! 	tst	passno
! 	bpl	saexit
! 	rts	pc
  
+ osymout:
+ 9:
+ 	mov	r2,symblk		/ save ptr to current sym block
+ 	tst	(r2)+			/ skip link word
+ 	mov	$SYMBLKSZ,symleft	/ space left in symbol block
+ 1:
+ 	mov	(r2),r4			/ pointer to symbol name
+ 	beq	4f			/ end of block - br
+ 
+ 	mov	$8.,r5			/ max number to copy
+ 	mov	$symbol,r0		/ destination buffer
+ 2:
+ 	movb	(r4),(r0)+		/ copy a byte
+ 	beq	6f
+ 	inc	r4			/ non null - bump source ptr
+ 6:
+ 	sob	r5,2b
+ 
+ / Now put four words of symbol name to the object file
+ 	mov	$4,r5			/ number of words to do
+ 	mov	$symbol,r4
+ 6:
+ 	mov	(r4)+,r0		/ word (2 chars) of symbol name
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw
+ 	sob	r5,6b
+ 
+ / values from 'hshtab' (parallel array to symbol table) are retrieved now,
+ / they take the place of the flags and value entries of the symbol table.
+ 	mov	(r1)+,r0
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw
+ 	mov	(r1)+,r0
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw
+ 	add	$SYMENTSZ,r2		/ skip to next symbol
+ 	sub	$SYMENTSZ,symleft	/ one less symbol in block
+ 	cmp	symleft,$SYMENTSZ	/ room for another?
+ 	bge	1b			/ yes - br
+ 4:
+ 	mov	*symblk,r2		/ no, follow link to next block
+ 	bne	9b			/ unless it's end of list
+ 	rts	pc
+ 
+ nsymout:
+ 	clr	totalsz
+ 	mov	$4,totalsz+2		/ string table min size is 4
+ 9:
+ 	mov	r2,symblk		/ save ptr to current symbol block
+ 	tst	(r2)+			/ skip link word
+ 	mov	$SYMBLKSZ,symleft	/ amount of space left in block
+ 1:
+ 	mov	(r2),r4			/ pointer to symbol's string
+ 	beq	4f			/ end of block - br
+ 	mov	totalsz,r0		/ now output the...
+ 	mov	$txtp,-(sp)		/ high order of the string index...
+ 	jsr	pc,putw			/ to the object file
+ 	mov	totalsz+2,r0
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw			/ and the low order word
+ 2:
+ 	tstb	(r4)+			/ find the end of the string
+ 	bne	2b
+ 	sub	(r2),r4			/ compute length including the null
+ 	add	r4,totalsz+2		/ offset of next string
+ 	adc	totalsz
+ 	mov	(r1)+,r0		/ 'type' word of symbol
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw
+ 	mov	(r1)+,r0		/ 'value' word of symbol
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw
+ 	add	$SYMENTSZ,r2		/ advance to next symbol
+ 	sub	$SYMENTSZ,symleft	/ adjust amount left in symbol block
+ 	cmp	symleft,$SYMENTSZ	/ is there enough for another symbol?
+ 	bge	1b			/ yes - br
+ 4:
+ 	mov	*symblk,r2		/ follow link to next symbol block
+ 	bne	9b			/ more - br
+ 	mov	totalsz,r0		/ now output the string table length
+ 	mov	$txtp,-(sp)		/ high order word first
+ 	jsr	pc,putw
+ 	mov	totalsz+2,r0		/ followed by the low order
+ 	mov	$txtp,-(sp)
+ 	jsr	pc,putw
+ 
+ / Now write the strings out
+ 
+ 	mov	usymtab,r2		/ start at beginning of symbols
+ 9:
+ 	mov	r2,symblk		/ save pointer to current block
+ 	tst	(r2)+			/ skip link word
+ 	mov	$SYMBLKSZ,symleft	/ amount left in block
+ 1:
+ 	mov	(r2),r4			/ pointer to symbol's string
+ 	beq	4f			/ at end of block - br
+ 	jsr	pc,putstring		/ write out the string
+ 	add	$SYMENTSZ,r2		/ advance to next symbol
+ 	sub	$SYMENTSZ,symleft	/ adjust amount left in block
+ 	cmp	symleft,$SYMENTSZ	/ enough for another symbol?
+ 	bge	1b			/ yes - br
+ 4:
+ 	mov	*symblk,r2		/ move to next block of symbols
+ 	bne	9b			/ any left - br
+ 
+ / probably not necessary but let us leave the file size on an even
+ / byte boundary.
+ 
+ 	bit	$1,totalsz+2		/ odd number of bytes in string table?
+ 	beq	5f			/ no - br
+ 	mov	symblk,r4		/ we know 'symblk' points to a null
+ 	jsr	pc,putstring		/ output a single null
+ 5:
+ 	rts	pc
+ 
+ / R4 has the address of a null terminated string to write to the output
+ / file.  The terminating null is included in the output.  This routine
+ / "inlines" the 'txtp seek structure' manipulation because the 'putw'
+ / routine was 1) not suitable to byte output and 2) symbol strings are
+ / only written using the 'txtp' (as opposed to 'relp' - relocation info)
+ / structure.
+ 
+ putstring:
+ 	cmp	txtp,txtp+2		/ room for another byte?
+ 	bhis	1f			/ no - br
+ 3:
+ 	movb	(r4),*txtp		/ put byte in buffer
+ 	inc	txtp			/ advance output position
+ 	tstb	(r4)+			/ did we just do the null?
+ 	bne	putstring		/ no - go again
+ 	rts	pc			/ yes - we're done, return
+ 1:
+ 	mov	r2,-(sp)		/ save r2 from being destroyed
+ 	mov	$txtp,-(sp)		/ flush buffered output and...
+ 	jsr	pc,flush		/ reset the pointers
+ 	mov	(sp)+,r2		/ restore symbol pointer
+ 	br	3b			/ go output a byte
+ 
  doreloc:
  	movb	(r1),r0
  	bne	1f
***************
*** 298,355 ****
  1:
  	rts	pc
  
- setbrk:
- 	mov	r1,-(sp)
- 	add	$20,r1
- 	cmp	r1,0f
- 	blo	1f
- 	add	$512.,0f
- 
- 	mov	0f,-(sp)		/ brk(0f)
- 	jsr	pc,_brk			/	sys	indir; 9f
- 	tst	(sp)+			/	.data
- .data					/9:	sys	sbreak; 0: end
- 0:	_end				/	.text
- .text
- 1:
- 	mov	(sp)+,r1
- 	rts	pc
- 
  setup:
  	mov	$curfb,r4
  1:
  	clr	(r4)+
  	cmp	r4,$curfb+40.
  	blo	1b
- 	mov	txtfil,fin
- 	clr	ibufc
  	clr	r4
  1:
  	jsr	pc,fbadv
! 	tstb	(r4)+
  	cmp	r4,$10.
  	blt	1b
! 	rts	pc
! 
! ofile:
! 	mov	r1,-(sp)		/ protect r1 from library
! 	clr	-(sp)			/ open(r0, O_RDONLY, 0)
  	clr	-(sp)
! 	mov	10(sp),-(sp)
! 	jsr	pc,_open
! 	add	$6,sp
! 	mov	(sp)+,r1
! 	tst	r0
! 	bmi	1f
! 	mov	(sp)+,(sp)
  	rts	pc
- 1:
- 	jmp	filerr
- /
- /
  
- / a2 -- pdp-11 assembler pass 2
- 
  outw:
  	cmp	dot-2,$4
  	beq	9f
--- 401,433 ----
  1:
  	rts	pc
  
  setup:
+ 	clr	dot
+ 	mov	$2,dotrel
+ 	mov	$..,dotdot
+ 	clr	brtabp
+ 
  	mov	$curfb,r4
  1:
  	clr	(r4)+
  	cmp	r4,$curfb+40.
  	blo	1b
  	clr	r4
  1:
  	jsr	pc,fbadv
! 	inc	r4
  	cmp	r4,$10.
  	blt	1b
! / just rewind /tmp/atm1xx rather than close and re-open
  	clr	-(sp)
! 	clr	-(sp)
! 	clr	-(sp)
! 	mov	fin,-(sp)
! 	jsr	pc,_lseek		/ lseek(fin, 0L, 0)
! 	add	$8.,sp
! 	clr	ibufc
  	rts	pc
  
  outw:
  	cmp	dot-2,$4
  	beq	9f
***************
*** 356,381 ****
  	bit	$1,dot
  	bne	1f
  	add	$2,dot
! 	tstb	passno
  	beq	8f
  	clr	-(sp)
  	rol	r3
  	adc	(sp)
! 	asr	r3		/ get relative pc bit
  	cmp	r3,$40
  	bne	2f
  / external references
  	mov	$666,outmod		/ make nonexecutable
  	mov	xsymbol,r3
! 	sub	usymtab,r3
  	asl	r3
! 	bis	$4,r3		/ external relocation
  	br	3f
  2:
! 	bic	$40,r3		/ clear any ext bits
  	cmp	r3,$5
  	blo	4f
! 	cmp	r3,$33		/ est. text, data
  	beq	6f
  	cmp	r3,$34
  	bne	7f
--- 434,459 ----
  	bit	$1,dot
  	bne	1f
  	add	$2,dot
! 	tst	passno
  	beq	8f
  	clr	-(sp)
  	rol	r3
  	adc	(sp)
! 	asr	r3			/ get relative pc bit
  	cmp	r3,$40
  	bne	2f
  / external references
  	mov	$666,outmod		/ make nonexecutable
  	mov	xsymbol,r3
! 	sub	hshtab,r3
  	asl	r3
! 	bis	$4,r3			/ external relocation
  	br	3f
  2:
! 	bic	$40,r3			/ clear any ext bits
  	cmp	r3,$5
  	blo	4f
! 	cmp	r3,$33			/ est. text, data
  	beq	6f
  	cmp	r3,$34
  	bne	7f
***************
*** 383,389 ****
  	mov	$'r,-(sp)
  	jsr	pc,error
  7:
! 	mov	$1,r3		/ make absolute
  4:
  	cmp	r3,$2
  	blo	5f
--- 461,467 ----
  	mov	$'r,-(sp)
  	jsr	pc,error
  7:
! 	mov	$1,r3			/ make absolute
  4:
  	cmp	r3,$2
  	blo	5f
***************
*** 424,430 ****
  	clr	r3
  	jsr	pc,outb
  	rts	pc
- 
  9:
  	mov	$'x,-(sp)
  	jsr	pc,error
--- 502,507 ----
***************
*** 438,444 ****
  	mov	$'r,-(sp)
  	jsr	pc,error
  1:
! 	tstb	passno
  	beq	2f
  	mov	r2,r0
  	bit	$1,dot
--- 515,521 ----
  	mov	$'r,-(sp)
  	jsr	pc,error
  1:
! 	tst	passno
  	beq	2f
  	mov	r2,r0
  	bit	$1,dot
***************
*** 462,525 ****
  	inc	dot
  	rts	pc
  
! error:
! 	mov	pc,errflg
! 	mov	$666,outmod		/ make nonexecutable
! 	mov	r3,-(sp)
! 	mov	r2,-(sp)
! 	mov	r1,-(sp)
! 	mov	r0,-(sp)
  
! 	tst	-(sp)			/ write(1, argb, strlen(argb))
! 	mov	$argb,-(sp)
! 	mov	$1,-(sp)
! 	mov	$argb,r1
! 	clr	r0
! 1:
! 	tstb	(r1)+
! 	beq	2f
! 	inc	r0
! 	br	1b
! 2:
! 	mov	r0,4(sp)
! 	jsr	pc,_write
! 	add	$6,sp
! 
! 	movb	12(sp),0f
! 	mov	line,r3
! 	mov	$0f+6,r0
! 	mov	$4,r1
! 2:
! 	clr	r2
! 	div	$10.,r2
! 	add	$'0,r3
! 	movb	r3,-(r0)
! 	mov	r2,r3
! 	sob	r1,2b
! 
! 	mov	$7,-(sp)		/ write(1, 0f, 7)
! 	mov	$0f,-(sp)		/	mov	$1,r0
! 	mov	$1,-(sp)		/	sys	write; 0f; 7
! 	jsr	pc,_write
! 	add	$6,sp
! 
! 	mov	(sp)+,r0
! 	mov	(sp)+,r1
! 	mov	(sp)+,r2
! 	mov	(sp)+,r3
! 	mov	(sp)+,(sp)
! 	rts	pc
! 
! 	.data
! 0:	<f xxxx\n>
! 	.even
! 	.text
! /
! /
! 
! / a3 -- pdp-11 assembler pass 2
! 
! assem:
  	jsr	pc,readop
  	cmp	r4,$5
  	beq	2f
--- 539,547 ----
  	inc	dot
  	rts	pc
  
! / pass 1 and 2 common code
  
! pass1_2:
  	jsr	pc,readop
  	cmp	r4,$5
  	beq	2f
***************
*** 544,550 ****
  2:
  	jsr	pc,opline
  dotmax:
! 	tstb	passno
  	bne	eal1
  	movb	dotrel,r0
  	asl	r0
--- 566,572 ----
  2:
  	jsr	pc,opline
  dotmax:
! 	tst	passno
  	bne	eal1
  	movb	dotrel,r0
  	asl	r0
***************
*** 563,571 ****
  	beq	3f
  	mov	$'x,-(sp)
  	jsr	pc,error
! 	br	assem
  1:
! 	tstb	passno
  	bne	2f
  	movb	(r4),r0
  	bic	$!37,r0
--- 585,593 ----
  	beq	3f
  	mov	$'x,-(sp)
  	jsr	pc,error
! 	br	pass1_2
  1:
! 	tst	passno
  	bne	2f
  	movb	(r4),r0
  	bic	$!37,r0
***************
*** 583,595 ****
  	mov	2(r4),brdelt
  	sub	dot,brdelt
  	mov	dot,2(r4)
! 	br	assem
  2:
  	cmp	dot,2(r4)
! 	beq	assem
  	mov	$'p,-(sp)
  	jsr	pc,error
! 	br	assem
  3:
  	mov	numval,r4
  	jsr	pc,fbadv
--- 605,617 ----
  	mov	2(r4),brdelt
  	sub	dot,brdelt
  	mov	dot,2(r4)
! 	br	pass1_2
  2:
  	cmp	dot,2(r4)
! 	beq	pass1_2
  	mov	$'p,-(sp)
  	jsr	pc,error
! 	br	pass1_2
  3:
  	mov	numval,r4
  	jsr	pc,fbadv
***************
*** 599,615 ****
  	mov	2(r0),brdelt
  	sub	dot,brdelt
  	mov	dot,2(r0)
! 	br	assem
  4:
  	jsr	pc,readop
  	jsr	pc,expres
  	mov	(sp)+,r1
! 	cmp	r1,$symtab	/test for dot
  	bne	1f
  	bic	$40,r3
! 	cmp	r3,dotrel	/ can't change relocation
  	bne	2f
! 	cmp	r3,$4		/ bss
  	bne	3f
  	mov	r2,dot
  	br	dotmax
--- 621,637 ----
  	mov	2(r0),brdelt
  	sub	dot,brdelt
  	mov	dot,2(r0)
! 	br	pass1_2
  4:
  	jsr	pc,readop
  	jsr	pc,expres
  	mov	(sp)+,r1
! 	cmp	r1,$dotrel		/test for dot
  	bne	1f
  	bic	$40,r3
! 	cmp	r3,dotrel		/ can't change relocation
  	bne	2f
! 	cmp	r3,$4			/ bss
  	bne	3f
  	mov	r2,dot
  	br	dotmax
***************
*** 654,660 ****
  1:
  	inc	line
  9:
! 	jmp	assem
  
  checkeos:
  	cmp	r4,$'\n
--- 676,682 ----
  1:
  	inc	line
  9:
! 	jmp	pass1_2
  
  checkeos:
  	cmp	r4,$'\n
***************
*** 685,695 ****
  	mov	r1,nxtfb(r4)
  	asr	r4
  	rts	pc
- /
- /
  
- / a4 -- pdp-11 assembler pass 2
- 
  oset:
  	mov	r2,-(sp)
  	mov	r3,-(sp)
--- 707,713 ----
***************
*** 698,709 ****
  	bic	$!1777,r1
  	add	r3,r1
  	add	$8,r1
! 	mov	r1,(r3)+	/ next slot
  	mov	r3,r1
  	add	$2006,r1
! 	mov	r1,(r3)+	/ buf max
  	mov	r0,(r3)+
! 	mov	r2,(r3)+	/ seek addr
  	mov	(sp)+,r3
  	mov	(sp)+,r2
  	mov	(sp)+,(sp)
--- 716,727 ----
  	bic	$!1777,r1
  	add	r3,r1
  	add	$8,r1
! 	mov	r1,(r3)+		/ next slot
  	mov	r3,r1
  	add	$2006,r1
! 	mov	r1,(r3)+		/ buf max
  	mov	r0,(r3)+
! 	mov	r2,(r3)+		/ seek addr
  	mov	(sp)+,r3
  	mov	(sp)+,r2
  	mov	(sp)+,(sp)
***************
*** 713,720 ****
  	mov	r1,-(sp)
  	mov	r2,-(sp)
  	mov	6(sp),r2
! 	mov	(r2)+,r1	/ slot
! 	cmp	r1,(r2)		/ buf max
  	bhis	1f
  	mov	r0,(r1)+
  	mov	r1,-(r2)
--- 731,738 ----
  	mov	r1,-(sp)
  	mov	r2,-(sp)
  	mov	6(sp),r2
! 	mov	(r2)+,r1		/ slot
! 	cmp	r1,(r2)			/ buf max
  	bhis	1f
  	mov	r0,(r1)+
  	mov	r1,-(r2)
***************
*** 730,735 ****
--- 748,754 ----
  	mov	(sp)+,r2
  	mov	(sp)+,r1
  	mov	(sp)+,(sp)
+ ret:
  	rts	pc
  
  flush:
***************
*** 739,765 ****
  flush1:
  
  	clr	-(sp)			/ lseek(fout, (r2)L+, L_SET)
! 	mov	2(r2),-(sp)		/	mov	(r2)+,0f
! 	mov	(r2)+,-(sp)		/	mov	(r2)+,r1
! 	tst	(r2)+			/	mov	r1,0f+2
! 	mov	fout,-(sp)		/	mov	fout,r0
! 	jsr	pc,_lseek		/	sys	indir; 9f
! 	add	$8.,sp			/	.data
! 					/9:	sys	lseek; 0:..; ..; 0
! 					/	.text
  	cmp	-(sp),-(sp)		/ write(fout, <buf>, <len>)
  	bic	$!1777,r1
! 	add	r2,r1		/ write address
  	mov	r1,-(sp)		/ { <buf> }
  	mov	r2,r0
  	bis	$1777,-(r2)
! 	add	$1,(r2)		/ new seek addr
  	adc	-(r2)
  	cmp	-(r2),-(r2)
  	sub	(r2),r1
  	neg	r1
! 	mov	r1,2(sp)	/ count
! 	mov	r0,(r2)		/ new next slot
  
  	mov	fout,-(sp)
  	mov	r1,6(sp)		/ protect r1 from library
--- 758,783 ----
  flush1:
  
  	clr	-(sp)			/ lseek(fout, (r2)L+, L_SET)
! 	mov	2(r2),-(sp)
! 	mov	(r2)+,-(sp)
! 	tst	(r2)+
! 	mov	fout,-(sp)
! 	jsr	pc,_lseek
! 	add	$8.,sp
! 
  	cmp	-(sp),-(sp)		/ write(fout, <buf>, <len>)
  	bic	$!1777,r1
! 	add	r2,r1			/ write address
  	mov	r1,-(sp)		/ { <buf> }
  	mov	r2,r0
  	bis	$1777,-(r2)
! 	add	$1,(r2)			/ new seek addr
  	adc	-(r2)
  	cmp	-(r2),-(r2)
  	sub	(r2),r1
  	neg	r1
! 	mov	r1,2(sp)		/ count
! 	mov	r0,(r2)			/ new next slot
  
  	mov	fout,-(sp)
  	mov	r1,6(sp)		/ protect r1 from library
***************
*** 767,787 ****
  	add	$6,sp
  	mov	(sp)+,r1
  	tst	r0
! 	jmi	wrterr
! 	rts	pc
  
  wrterr:
! 	mov	$8f-9f,-(sp)		/ write(1, ERRMSG, strlen(ERRMSG))
! 	mov	$9f,-(sp)		/	mov	$1,r0
! 	mov	$1,-(sp)		/	sys	write; 9f; 8f-9f
  	jsr	pc,_write
  	add	$6,sp
- 
  	jmp	saexit
- .data
- 9:	<as: write error on output\n>; 8: .even
- .text
  
  readop:
  	mov	savop,r4
  	beq	1f
--- 785,808 ----
  	add	$6,sp
  	mov	(sp)+,r1
  	tst	r0
! 	bpl	ret
! / fall thru to wrterr
  
  wrterr:
! 	mov	$8f-9f,-(sp)		/ write(1, 9f, 8f-9f)
! 	mov	$9f,-(sp)
! 	mov	$1,-(sp)
  	jsr	pc,_write
  	add	$6,sp
  	jmp	saexit
  
+ 	.data
+ 9:
+ 	<as: write error\n>
+ 8:
+ 	.even
+ 	.text
+ 
  readop:
  	mov	savop,r4
  	beq	1f
***************
*** 793,803 ****
  	blo	1f
  	cmp	r4,$4000
  	blo	2f
- 	add	usymtab,r4
  	sub	$4000,r4
  	rts	pc
  2:
! 	add	$symtab-1000,r4
  1:
  	rts	pc
  
--- 814,835 ----
  	blo	1f
  	cmp	r4,$4000
  	blo	2f
  	sub	$4000,r4
+ 	asl	r4
+ 	asl	r4
+ 	add	hshtab,r4
  	rts	pc
  2:
! / remove PST flag (1000) then multiply by PSTENTSZ.  In pass 0 the PST
! / symbol number was divided by PSTENTSZ(to make it fit) - we now reverse
! / that process.
! 	mov	r5,-(sp)
! 	mov	r4,r5
! 	sub	$1000,r5
! 	mul	$PSTENTSZ,r5
! 	mov	r5,r4
! 	mov	(sp)+,r5
! 	add	$dotrel,r4		/ point at dot's flag field
  1:
  	rts	pc
  
***************
*** 812,829 ****
  
  	mov	r1,-(sp)		/ protect r1 from library
  	mov	$1024.,-(sp)		/ read(fin, inbuf, 1024)
! 	mov	$inbuf,-(sp)		/	movb	fin,r0
! 	mov	fin,-(sp)		/	sys	read; inbuf; 1024.
! 	jsr	pc,_read		/	bes	3f
  	add	$6,sp
  	mov	(sp)+,r1
- 	tst	r0
- 	jmi	3f
- 
  	asr	r0
  	mov	r0,ibufc
! 	bne	2f
! 3:
  	mov	$4,r4
  	sev
  	rts	pc
--- 844,857 ----
  
  	mov	r1,-(sp)		/ protect r1 from library
  	mov	$1024.,-(sp)		/ read(fin, inbuf, 1024)
! 	mov	$inbuf,-(sp)
! 	mov	fin,-(sp)
! 	jsr	pc,_read
  	add	$6,sp
  	mov	(sp)+,r1
  	asr	r0
  	mov	r0,ibufc
! 	bgt	2f
  	mov	$4,r4
  	sev
  	rts	pc
***************
*** 833,847 ****
  	mov	*ibufp,r4
  	add	$2,ibufp
  	rts	pc
- /
- /
  
- / as25 is empty
- /
- /
- 
- / a6 -- pdp-11 assembler pass 2
- 
  opline:
  	mov	r4,r0
  	bmi	2f
--- 861,867 ----
***************
*** 860,870 ****
  	rts	pc
  2:
  	movb	(r4),r0
! 	cmp	r0,$24		/reg
  	beq	xpr
! 	cmp	r0,$33		/est text
  	beq	xpr
! 	cmp	r0,$34		/ est data
  	beq	xpr
  	cmp	r0,$5
  	blt	xpr
--- 880,890 ----
  	rts	pc
  2:
  	movb	(r4),r0
! 	cmp	r0,$24			/reg
  	beq	xpr
! 	cmp	r0,$33			/est text
  	beq	xpr
! 	cmp	r0,$34			/ est data
  	beq	xpr
  	cmp	r0,$5
  	blt	xpr
***************
*** 928,946 ****
  	tst	(sp)+
  	rts	pc
  
! opl30:	/ mpy, dvd etc
  	inc	swapf
  	mov	$1000,rlimit
  	br	opl13
  
! opl14:		/ flop freg,fsrc
  	inc	swapf
  
! opl5:		/ flop src,freg
  	mov	$400,rlimit
  
! /double
! opl13:
  	jsr	pc,addres
  op2a:
  	mov	r2,-(sp)
--- 948,965 ----
  	tst	(sp)+
  	rts	pc
  
! opl30:					/ mul, div etc
  	inc	swapf
  	mov	$1000,rlimit
  	br	opl13
  
! opl14:					/ flop freg,fsrc
  	inc	swapf
  
! opl5:					/ flop src,freg
  	mov	$400,rlimit
  
! opl13:					/double
  	jsr	pc,addres
  op2a:
  	mov	r2,-(sp)
***************
*** 977,990 ****
  1:
  	rts	pc
  
! opl15:		/ single operand
  	clr	-(sp)
  	br	op2b
  
! opl12:		/ movf
  	mov	$400,rlimit
  	jsr	pc,addres
! 	cmp	r2,$4		/ see if source is fregister
  	blo	1f
  	inc	swapf
  	br	op2a
--- 996,1009 ----
  1:
  	rts	pc
  
! opl15:					/ single operand
  	clr	-(sp)
  	br	op2b
  
! opl12:					/ movf
  	mov	$400,rlimit
  	jsr	pc,addres
! 	cmp	r2,$4			/ see if source is fregister
  	blo	1f
  	inc	swapf
  	br	op2a
***************
*** 992,1003 ****
  	mov	$174000,(sp)
  	br	op2a
  
! / jbr
! opl35:
! / jeq, jne, etc
! opl36:
  	jsr	pc,expres
! 	tstb	passno
  	bne	1f
  	mov	r2,r0
  	jsr	pc,setbr
--- 1011,1020 ----
  	mov	$174000,(sp)
  	br	op2a
  
! opl35:					/ jbr
! opl36:					/ jeq, jne, etc
  	jsr	pc,expres
! 	tst	passno
  	bne	1f
  	mov	r2,r0
  	jsr	pc,setbr
***************
*** 1007,1013 ****
  	beq	2f
  	add	$2,r2
  2:
! 	add	r2,dot		/ if doesn't fit
  	add	$2,dot
  	tst	(sp)+
  	rts	pc
--- 1024,1030 ----
  	beq	2f
  	add	$2,r2
  2:
! 	add	r2,dot			/ if doesn't fit
  	add	$2,dot
  	tst	(sp)+
  	rts	pc
***************
*** 1020,1026 ****
  	cmp	r0,$br
  	beq	2f
  	mov	$402,r2
! 	xor	r0,r2		/ flip cond, add ".+6"
  	mov	$1,r3
  	jsr	pc,outw
  2:
--- 1037,1043 ----
  	cmp	r0,$br
  	beq	2f
  	mov	$402,r2
! 	xor	r0,r2			/ flip cond, add ".+6"
  	mov	$1,r3
  	jsr	pc,outw
  2:
***************
*** 1032,1039 ****
  	jsr	pc,outw
  	rts	pc
  
! /sob
! opl31:	/ sob
  	jsr	pc,expres
  	jsr	pc,checkreg
  	swab	r2
--- 1049,1055 ----
  	jsr	pc,outw
  	rts	pc
  
! opl31:					/ sob
  	jsr	pc,expres
  	jsr	pc,checkreg
  	swab	r2
***************
*** 1042,1048 ****
  	bis	r2,(sp)
  	jsr	pc,readop
  	jsr	pc,expres
! 	tstb	passno
  	beq	3f
  	sub	dot,r2
  	neg	r2
--- 1058,1064 ----
  	bis	r2,(sp)
  	jsr	pc,readop
  	jsr	pc,expres
! 	tst	passno
  	beq	3f
  	sub	dot,r2
  	neg	r2
***************
*** 1054,1063 ****
  	add	$4,r2
  	br	1f
  
! /branch
! opl6:
  	jsr	pc,expres
! 	tstb	passno
  	beq	3f
  dobranch:
  	sub	dot,r2
--- 1070,1078 ----
  	add	$4,r2
  	br	1f
  
! opl6:					/branch
  	jsr	pc,expres
! 	tst	passno
  	beq	3f
  dobranch:
  	sub	dot,r2
***************
*** 1069,1075 ****
  1:
  	bit	$1,r2
  	bne	2f
! 	cmp	r3,dot-2	/ same relocation as .
  	bne	2f
  	asr	r2
  	dec	r2
--- 1084,1090 ----
  1:
  	bit	$1,r2
  	bne	2f
! 	cmp	r3,dot-2		/ same relocation as .
  	bne	2f
  	asr	r2
  	dec	r2
***************
*** 1085,1104 ****
  	clr	r2
  	br	3b
  
! /jsr
! opl7:
  	jsr	pc,expres
  	jsr	pc,checkreg
  	jmp	op2a
  
! / rts
! opl10:
  	jsr	pc,expres
  	jsr	pc,checkreg
  	br	1f
  
! / sys, emt etc
! opl11:
  	jsr	pc,expres
  	cmp	r2,$256.
  	bhis	0f
--- 1100,1116 ----
  	clr	r2
  	br	3b
  
! opl7:					/jsr
  	jsr	pc,expres
  	jsr	pc,checkreg
  	jmp	op2a
  
! opl10:					/ rts
  	jsr	pc,expres
  	jsr	pc,checkreg
  	br	1f
  
! opl11:					/ sys
  	jsr	pc,expres
  	cmp	r2,$256.
  	bhis	0f
***************
*** 1111,1118 ****
  	jsr	pc,outw
  	rts	pc
  
! / .byte
! opl16:
  	jsr	pc,expres
  	jsr	pc,outb
  	cmp	r4,$',
--- 1123,1129 ----
  	jsr	pc,outw
  	rts	pc
  
! opl16:					/ .byte
  	jsr	pc,expres
  	jsr	pc,outb
  	cmp	r4,$',
***************
*** 1123,1130 ****
  	tst	(sp)+
  	rts	pc
  
! / < (.ascii)
! opl17:
  	jsr	pc,getw
  	mov	$1,r3
  	mov	r4,r2
--- 1134,1140 ----
  	tst	(sp)+
  	rts	pc
  
! opl17:					/ < (.ascii)
  	jsr	pc,getw
  	mov	$1,r3
  	mov	r4,r2
***************
*** 1136,1147 ****
  	jsr	pc,getw
  	rts	pc
  
! /.even
! opl20:
  	bit	$1,dot
  	beq	1f
  	cmp	dot-2,$4
! 	beq	2f		/ bss mode
  	clr	r2
  	clr	r3
  	jsr	pc,outb
--- 1146,1156 ----
  	jsr	pc,getw
  	rts	pc
  
! opl20:					/.even
  	bit	$1,dot
  	beq	1f
  	cmp	dot-2,$4
! 	beq	2f			/ bss mode
  	clr	r2
  	clr	r3
  	jsr	pc,outb
***************
*** 1151,1157 ****
  1:
  	tst	(sp)+
  	rts	pc
! opl21:	/if
  	jsr	pc,expres
  opl22:
  oplret:
--- 1160,1167 ----
  1:
  	tst	(sp)+
  	rts	pc
! 
! opl21:					/if
  	jsr	pc,expres
  opl22:
  oplret:
***************
*** 1158,1165 ****
  	tst	(sp)+
  	rts	pc
  
! /.globl
! opl23:
  	cmp	r4,$200
  	blo	1f
  	bisb	$40,(r4)
--- 1168,1174 ----
  	tst	(sp)+
  	rts	pc
  
! opl23:					/.globl
  	cmp	r4,$200
  	blo	1f
  	bisb	$40,(r4)
***************
*** 1172,1179 ****
  	tst	(sp)+
  	rts	pc
  
! / .text, .data, .bss
! opl25:
  opl26:
  opl27:
  	inc	dot
--- 1181,1187 ----
  	tst	(sp)+
  	rts	pc
  
! opl25:					/ .text, .data, .bss
  opl26:
  opl27:
  	inc	dot
***************
*** 1182,1188 ****
  	mov	dot-2,r1
  	asl	r1
  	mov	dot,savdot-4(r1)
! 	tstb	passno
  	beq	1f
  	mov	$txtp,-(sp)
  	jsr	pc,flush
--- 1190,1196 ----
  	mov	dot-2,r1
  	asl	r1
  	mov	dot,savdot-4(r1)
! 	tst	passno
  	beq	1f
  	mov	$txtp,-(sp)
  	jsr	pc,flush
***************
*** 1207,1213 ****
  	mov	savdot-[2*25](r0),dot
  	asr	r0
  	sub	$25-2,r0
! 	mov	r0,dot-2	/ new . relocation
  	tst	(sp)+
  	rts	pc
  
--- 1215,1221 ----
  	mov	savdot-[2*25](r0),dot
  	asr	r0
  	sub	$25-2,r0
! 	mov	r0,dot-2		/ new . relocation
  	tst	(sp)+
  	rts	pc
  
***************
*** 1337,1347 ****
  	jsr	pc,readop
  	jmp	4b
  
- errora:
- 	mov	$'a,-(sp)
- 	jsr	pc,error
- 	rts	pc
- 
  checkreg:
  	cmp	r2,$7
  	bhi	1f
--- 1345,1350 ----
***************
*** 1357,1367 ****
  	clr	r3
  	rts	pc
  
- errore:
- 	mov	$'e,-(sp)
- 	jsr	pc,error
- 	rts	pc
- 
  checkrp:
  	cmp	r4,$')
  	beq	1f
--- 1360,1365 ----
***************
*** 1415,1427 ****
  	ash	$-3,r1
  	movb	brtab(r1),r1
  	ash	(sp)+,r1
! 	ror	r1		/ 0-bit into c-bit
  	rts	pc
- /
- /
  
- /  a7 -- pdp-11 assembler
- 
  expres:
  	clr	xsymbol
  expres1:
--- 1413,1421 ----
  	ash	$-3,r1
  	movb	brtab(r1),r1
  	ash	(sp)+,r1
! 	ror	r1			/ 0-bit into c-bit
  	rts	pc
  
  expres:
  	clr	xsymbol
  expres1:
***************
*** 1439,1447 ****
  	ble	7f
  6:
  	movb	(r4),r0
- 	tst	r0
  	bne	1f
! 	tstb	passno
  	beq	1f
  	mov	$'u,-(sp)
  	jsr	pc,error
--- 1433,1440 ----
  	ble	7f
  6:
  	movb	(r4),r0
  	bne	1f
! 	tst	passno
  	beq	1f
  	mov	$'u,-(sp)
  	jsr	pc,error
***************
*** 1456,1464 ****
  / actually in another overlay. Elsewise, the assembler fix's up
  / the reference before the link editor changes the globl refrence
  / to the thunk. -wfj 5/80
! 	cmp	r0,$42		/ is it globl text ?
! 	bne	0f		/ nope
! 	mov	$40,r0		/ yes, treat it as undefined external
  0:
  	cmp	r0,$40
  	bne	1f
--- 1449,1457 ----
  / actually in another overlay. Elsewise, the assembler fix's up
  / the reference before the link editor changes the globl refrence
  / to the thunk. -wfj 5/80
! 	cmp	r0,$42			/ is it globl text ?
! 	bne	0f			/ nope
! 	mov	$40,r0			/ yes, treat it as undefined external
  0:
  	cmp	r0,$40
  	bne	1f
***************
*** 1646,1652 ****
  	jmp	advanc
  
  combin:
! 	tstb	passno
  	bne	combin1
  	mov	r0,-(sp)
  	bis	r3,(sp)
--- 1639,1645 ----
  	jmp	advanc
  
  combin:
! 	tst	passno
  	bne	combin1
  	mov	r0,-(sp)
  	bis	r3,(sp)
***************
*** 1736,1758 ****
  	.byte 0, X, X, X, X, X
  	.byte 0, X, X, X, X, X
  	.byte 0, X, X, X, X, X
- 	.text
- /
- /
  
- / as8 -- PDP-11 assembler pass 2
- 	.data
  qnl:	<?\n>
  a.out:	<a.out\0>
! .even
  a.outp:	a.out
  
! a.tmp1:	0
! a.tmp2:	0
! a.tmp3:	0
  
- overlaid: 0
- 
  tseekp:	txtseek
  rseekp:	trelseek
  
--- 1729,1744 ----
  	.byte 0, X, X, X, X, X
  	.byte 0, X, X, X, X, X
  	.byte 0, X, X, X, X, X
  
  qnl:	<?\n>
  a.out:	<a.out\0>
! 	.even
  a.outp:	a.out
  
! obufp:	outbuf
! passno: -1
! outmod:	0777
  
  tseekp:	txtseek
  rseekp:	trelseek
  
***************
*** 1762,1770 ****
  datsiz:	.=.+2
  bsssiz:	.=.+2
  symsiz:	.=.+2
! stksiz:	.=.+2
! exorig:	.=.+2
! 	.=.+2
  
  txtseek:0; 20
  datseek:.=.+4
--- 1748,1754 ----
  datsiz:	.=.+2
  bsssiz:	.=.+2
  symsiz:	.=.+2
! 	.=.+6
  
  txtseek:0; 20
  datseek:.=.+4
***************
*** 1774,2088 ****
  	.=.+4
  symseek:.=.+4
  
! .bss
! 
  brlen	= 1024.
  brtab:	.=.+[brlen\/8.]
  brtabp:	.=.+2
  brdelt:	.=.+2
! fbbufp:	.=.+2
  defund:	.=.+2
- savdot:	.=.+6
  datbase:.=.+2
  bssbase:.=.+2
- fbfil:	.=.+2
- fin:	.=.+2
  ibufc:	.=.+2
! txtfil:	.=.+2
! symf:	.=.+2
  adrbuf:	.=.+12.
  xsymbol:.=.+2
- fout:	.=.+2
- ch:	.=.+2
  errflg:	.=.+2
- wordf:	.=.+2
  argb:	.=.+22.
- line:	.=.+2
- savop:	.=.+2
- curfb:	.=.+20.
- nxtfb:	.=.+20.
  numval:	.=.+2
  maxtyp:	.=.+2
- relfil:	.=.+2
  ibufp:	.=.+2
! txtp:	.=.+8+1024.
! relp:	.=.+8+1024.
  swapf:	.=.+2
  rlimit:	.=.+2
- passno:	.=.+2
  endtable:.=.+2
! inbuf:	.=.+1024.
! .data
! usymtab: _end
! .text
! /
! /
! 
! / as9 -- PDP-11 assembler pass 2
! 
! 	.data
! symtab:
! 
! / special variables
! 
! dotrel: 02; dot:000000 /.
!  01; dotdot:000000 /..
! 
! / register
! 
! 24;000000 /r0
! 24;000001 /r1
! 24;000002 /r2
! 24;000003 /r3
! 24;000004 /r4
! 24;000005 /r5
! 24;000006 /sp
! 24;000007 /pc
! 
! / double operand
! 
! 13;0010000 /mov
! 13;0110000 /movb
! 13;0020000 /cmp
! 13;0120000 /cmpb
! 13;0030000 /bit
! 13;0130000 /bitb
! 13;0040000 /bic
! 13;0140000 /bicb
! 13;0050000 /bis
! 13;0150000 /bisb
! 13;0060000 /add
! 13;0160000 /sub
! 
! / branch
! 
! 06;0000400 /br
! 06;0001000 /bne
! 06;0001400 /beq
! 06;0002000 /bge
! 06;0002400 /blt
! 06;0003000 /bgt
! 06;0003400 /ble
! 06;0100000 /bpl
! 06;0100400 /bmi
! 06;0101000 /bhi
! 06;0101400 /blos
! 06;0102000 /bvc
! 06;0102400 /bvs
! 06;0103000 /bhis
! 06;0103000 /bec
! 06;0103000 /bcc
! 06;0103400 /blo
! 06;0103400 /bcs
! 06;0103400 /bes
! 
! / jump/ branch type
! 
! 35;0000400 /jbr
! 36;0001000 /jne
! 36;0001400 /jeq
! 36;0002000 /jge
! 36;0002400 /jlt
! 36;0003000 /jgt
! 36;0003400 /jle
! 36;0100000 /jpl
! 36;0100400 /jmi
! 36;0101000 /jhi
! 36;0101400 /jlos
! 36;0102000 /jvc
! 36;0102400 /jvs
! 36;0103000 /jhis
! 36;0103000 /jec
! 36;0103000 /jcc
! 36;0103400 /jlo
! 36;0103400 /jcs
! 36;0103400 /jes
! 
! / single operand
! 
! 15;0005000 /clr
! 15;0105000 /clrb
! 15;0005100 /com
! 15;0105100 /comb
! 15;0005200 /inc
! 15;0105200 /incb
! 15;0005300 /dec
! 15;0105300 /decb
! 15;0005400 /neg
! 15;0105400 /negb
! 15;0005500 /adc
! 15;0105500 /adcb
! 15;0005600 /sbc
! 15;0105600 /sbcb
! 15;0005700 /tst
! 15;0105700 /tstb
! 15;0006000 /ror
! 15;0106000 /rorb
! 15;0006100 /rol
! 15;0106100 /rolb
! 15;0006200 /asr
! 15;0106200 /asrb
! 15;0006300 /asl
! 15;0106300 /aslb
! 15;0000100 /jmp
! 15;0000300 /swab
! 15;0006500 /mfpi
! 15;0006600 /mtpi
! 15;0106500 /mfpd
! 15;0106600 /mtpd
! 15;0170300 /stst
! 15;0106700 /mfps
! 15;0106400 /mtps
! 15;0007000 /csm
! 15;0007200 /tstset
! 15;0007300 /wrtlck
! 
! / jsr
! 
! 07;0004000 /jsr
! 
! / rts
! 
! 10;000200 /rts
! 
! / simple operand
! 
! 11;104400 /sys
! 11;000230 /spl
! 
! / flag-setting
! 
! 01;0000240 /nop
! 01;0000241 /clc
! 01;0000242 /clv
! 01;0000244 /clz
! 01;0000250 /cln
! 01;0000261 /sec
! 01;0000262 /sev
! 01;0000264 /sez
! 01;0000270 /sen
! 01;0000000 /halt
! 01;0000001 /wait
! 01;0000004 /iot
! 01;0000005 /reset
! 01;0000006 /rtt
! 01;0000007 /mfpt
! 
! / floating point ops
! 
! 01;170000 / cfcc
! 01;170001 / setf
! 01;170011 / setd
! 01;170002 / seti
! 01;170012 / setl
! 15;170400 / clrf
! 15;170700 / negf
! 15;170600 / absf
! 15;170500 / tstf
! 12;172400 / movf
! 14;177000 / movif
! 05;175400 / movfi
! 14;177400 / movof
! 05;176000 / movfo
! 14;172000 / addf
! 14;173000 / subf
! 14;171000 / mulf
! 14;174400 / divf
! 14;173400 / cmpf
! 14;171400 / modf
! 14;176400 / movie
! 05;175000 / movei
! 15;170100 / ldfps
! 15;170200 / stfps
! 24;000000 / fr0
! 24;000001 / fr1
! 24;000002 / fr2
! 24;000003 / fr3
! 24;000004 / fr4
! 24;000005 / fr5
! 
! / 11/45 operations
! 
! 30;070000 /mul
! 30;071000 /div
! 30;072000 /ash
! 30;073000 /ashc
! 07;074000 /xor
! 15;006700 /sxt
! 11;006400 /mark
! 31;077000 /sob
! 
! / specials
! 
! 16;000000 /.byte
! 20;000000 /.even
! 21;000000 /.if
! 22;000000 /.endif
! 23;000000 /.globl
! 25;000000 /.text
! 26;000000 /.data
! 27;000000 /.bss
! 32;000000 /.comm
! 
! 	.text
! start:
! 	mov	(sp)+,r0
! 	tst	(sp)+
! 1:
! 	mov	(sp)+,r1
! 	cmpb	(r1),$'-
! 	bne	1f
! 	dec	r0
! 	cmpb	1(r1),$'g
! 	bne	2f
! 	mov	$40,defund	/ globalize externals
! 	br	1b
! 2:
! 	cmpb	1(r1), $'V
! 	bne	2f
! 	inc	overlaid
! 	br	1b
! 2:
! 	cmpb	1(r1),$'o
! 	bne	1b
! 	dec	r0
! 	mov	(sp)+,r1
! 	mov	r1,a.outp
! 	mov	r1,a.outp1
! 	mov	r1,a.outp2
! 	br	1b
! 1:
! 	cmp	r0,$4
! 	bge	1f
! 	jmp	aexit
! 1:
! 	mov	r1,a.tmp1
! 	mov	(sp)+,a.tmp2
! 	mov	(sp)+,a.tmp3
! 	mov	a.tmp1,-(sp)
! 	jsr	pc,ofile
! 	mov	r0,txtfil
! 	mov	a.tmp2,-(sp)
! 	jsr	pc,ofile
! 	mov	r0,fbfil
! 	mov	a.tmp3,-(sp)
! 	jsr	pc,ofile
! 	mov	r0,symf
! 	mov	r0,fin
! 
! 	mov	r1,-(sp)		/ protect r1 from library
! 	mov	$0666,-(sp)		/ creat(a.outp1, 0666)
! 	mov	a.outp1,-(sp)		/	sys	creat; a.outp1:a.out; 666
! 	jsr	pc,_creat		/	bec	1f
! 	cmp	(sp)+,(sp)+
! 	mov	(sp)+,r1
! 	tst	r0
! 	jpl	1f
! 	mov	a.outp,-(sp)
! 	jsr	pc,filerr
! 1:
! 	mov	r0,fout
! 	jmp	go
! 	.data
! a.outp1:	a.out
  	.text
--- 1758,1789 ----
  	.=.+4
  symseek:.=.+4
  
! 	.bss
  brlen	= 1024.
  brtab:	.=.+[brlen\/8.]
  brtabp:	.=.+2
  brdelt:	.=.+2
! fbbufp: .=.+2
  defund:	.=.+2
  datbase:.=.+2
  bssbase:.=.+2
  ibufc:	.=.+2
! overlaid: .=.+2
  adrbuf:	.=.+12.
  xsymbol:.=.+2
  errflg:	.=.+2
  argb:	.=.+22.
  numval:	.=.+2
  maxtyp:	.=.+2
  ibufp:	.=.+2
! txtp:	.=.+8.
! 	.=.+1024.
! relp:	.=.+8.
! outbuf:
! 	.=.+1024.
  swapf:	.=.+2
  rlimit:	.=.+2
  endtable:.=.+2
! totalsz:			/ string table length
! 	.=.+4
  	.text