PDP-10.its/src/syseng/gtload.14

	TITLE	LOADER

	CHK=16
	ERP=15
	PPTR=14
	C=4
	D=11
	CKSM=12
	REG=13
	F=7
	S=10
	SPNTR=10
	P=6
	PNTR=1
	A=2
	B=3
	CMPTR=4
	BCOUNT=5

	O.SYMS=-100.	;GETS ADDED TO IN DEBUGGER

BUFF:	BLOCK 40

RCH:	MOVE	PNTR,[10700,,BUFF-1]	;INITL BYTE PNTR TO BUFF
	MOVEM	PNTR,CMPTR
GCHR:	PUSHJ	P,TYI	;GET CHAR
	CAIN	A,177	;RUBOUT?
	JRST	RUBOT
	IDPB	A,PNTR
	CAIN A,33
	JRST GCHR1		;ALT MODE ALSO TERMINATES COMMAND
	CAIE	A,15	;CR?
	JRST	GCHR
GCHR1:	MOVEI	A,0	;IT WAS CR
	IDPB	A,PNTR	;MARK END OF STRNG
CPOPJ:	POPJ	P,

RUBOT:	CAMN	PNTR,[10700,,BUFF-1]	;RUBOUT AT BEG OF BUFFER?
	JRST	BRUB
	LDB	A,PNTR	;GET LAST CHAR TYPED
	PUSHJ	P,TYO	;ECHO IT
	ADD	PNTR,[70000,,]	;DECREMENT POINTER
	JUMPGE	PNTR,GCHR	;JUMP IF VALID
	SUB	PNTR,[430000,,1]	;WAS 440700,,SOMETHING, BACK IT UP
	JRST	GCHR

BRUB:	PUSHJ	P,CRR	;TYPE CR LF
	JRST	GCHR

TYI:	.IOT	TTI,A
	JUMPE	A,TYI
	CAIE	A,15
	POPJ	P,
	PUSHJ	P,CRR	;ECHO CR
	MOVEI	A,15
	POPJ	P,

TYO:	.IOT	TTO,A
	POPJ	P,

SCRS:	MOVEI	A,2
	PUSHJ	P,TYO
CRS:	MOVEI	A,"*
	PUSHJ	P,TYO
CRR:	MOVEI	A,15
	PUSHJ	P,TYO
	MOVEI	A,12
	JRST	TYO

	LINE==1
	TTO==1
	TTI==2
	DSK==3
	ERRC==4


BEGIN:	MOVE	P,[-100,,PLD]
	.OPEN	TTO,STTO
	.VALUE	0
	.OPEN	TTI,STTI
	.VALUE	0
	JRST	BCMD

STTO:	45,,(SIXBIT /TTY/)
STTI:	20,,(SIXBIT /TTY/)
STTI1:	4,,(SIXBIT /TTY/)

PLD:	BLOCK	100

BCMD:	CLEARM PASS		;PASS 0 - LOAD NORMAL, -1 LOAD LOADER LOADER
	PUSHJ	P,SCRS
	PUSHJ	P,RCH	;GET TYPED IN COMMANND
	MOVE	PNTR,IP
	SETZB	F,S
COMND:	ILDB	A,CMPTR
	CAIN	A,^Q
	JRST	CMDQ
	CAIN A,33		;ALT MODE TERMINATES COMMAND
	SOSA PASS		;AND SAYS TO USE LOADER LOADER (TO AVOID CLOBBERING)
	CAIN	A,15
	JRST	CMDE
	CAIN	A,^G
	JRST	BCMD
	CAIN	A,":
	JRST	CMDCOL
	CAIN	A,";
	JRST	CMDSC
	CAIG	A,40
	JRST	CMDS
SXBT:	SUBI	A,40
	CAIL	A,100
	 SUBI	A,40
	TLNE	PNTR,770000	;STOP AFTER POSITIN=0
	IDPB	A,PNTR
	JRST	COMND
CMDS:	MOVE	F,S
CMD1:	MOVE	PNTR,IP
	MOVEI	S,0
	JRST	COMND
CMDSC:	MOVEM	S,SNR
	JRST	CMD1
CMDCOL:	JRST	CMD1	;FOR NOW IGNORE IT

IP:	440600,,S

CMDE:	.SUSET	[.SSNAM,,SNR]
	JUMPE	F,FZ
	JUMPN	S,SNZ
FZ:	LSHC	F,36.	;MOVE S TO F AND ZERO S
SZ:	JUMPE	F,BCMD	;TAKE IN NEW NAME
	MOVE	S,BIN
SNZ:	MOVEM	F,ADR+1
	MOVEM	S,ADR+2
PASS2:	.OPEN	DSK,ADR
	JRST	ERROR
	SKIPGE PASS
	JRST LLDR		;LOAD LOADER LOADER FIRST
LLDR1:	.OPEN	LINE,[45,,'TTY]
	.VALUE		;SUPER-IMAGE OUT SO NO PADDING, ETC.
	.OPEN	TTI,STTI1	;SWITCH INTO IMAGE MODE
	.VALUE 0
	MOVEI	A,15
	.SLEEP	A,
	MOVEI	PNTR,0
	JRST	STBLK

LLDR:	.CALL LLOPN
	.VALUE
	JRST LLDR1

ERROR:	.OPEN	ERRC,ERR0
	.VALUE	0
ERR1:	.IOT	ERRC,A
	CAIN	A,3
	JRST	BCMD
	JUMPL	A,BCMD
	PUSHJ	P,TYO
	JRST	ERR1

PASS:	0		;0 LOAD REGULAR THING, -1 LOAD LOADER LOADER

ERR0:	SIXBIT /   ERR/
	1
	0

SNR:	0
ADR:	2,,(SIXBIT /DSK/)
	0
	0
BIN:	SIXBIT /BIN   /
 CMDQ:	ILDB	A,CMPTR
	JRST	SXBT

BTTO:	7,,(SIXBIT /TTY/)

LLOPN:	SETZ
	SIXBIT /OPEN/
	5000,,2
	1000,,DSK
	[SIXBIT /DSK/]
	[SIXBIT /GT40LL/]
	[SIXBIT /BIN/]
	SETZ+[SIXBIT /GT40/]

;PNTR HAS MINUS # LEFT SO ADRS(PNTR) GIVES NEXT WORD
;WHEN IT EQUALS 0, GET NEW BLOCK. IF RETURN WITH NEG
;POINTER, WRITE NEG 1 AS EOF CHAR

GETDSK:	JUMPE	PNTR,RELOD	;NEED NEW BLOCK
	MOVE	A,ADRS(PNTR)
	ANDI A,377
	AOJA	PNTR,CPOPJ	;ADD ONE AND RET URN
RELOD:	MOVE	PNTR,DBUFP
	.IOT	DSK,PNTR
	JUMPL	PNTR,ENFIL
NPNTR:	HLRE	PNTR,DBUFP	;GET MIN WRD COUNT IN PNTR
	JRST	GETDSK
ENFIL:	HRRZS	PNTR	;ZERO LEFT HALF TO GET NEXT ADRESS
	SETOM	(PNTR)	;WRITE EOF CHAR
	JRST	NPNTR

DBUFP:	-50,,BUFR
BUFR:	BLOCK	50
	ADRS=.
STBLK:	.IOT LINE,[175]
	.IOT LINE,["R]
	.IOT LINE,[175]
	.IOT LINE,["L]
	SETZB B,C
STBLK4:	.RESET TTI,
STBLK1:	PUSHJ P,GETDSK
	CAIE A,1	;START OF BLOCK?
	JRST STBLK1	;NOT YET
	PUSHJ P,SEND	;YES, SEND IT
	PUSHJ P,GETDSK	;AND THE ZERO FOLLOWING
	PUSHJ P,SEND
	PUSHJ P,GWRD	;GET COUNT
	MOVE D,C
	CAIN D,6
	JRST STBLK2
	SUBI D,4
STBLK3:	PUSHJ P,GETDSK
	PUSHJ P,SEND
	SOJGE D,STBLK3
	MOVEI A,TTI
	.LISTEN A,
	JUMPE A,STBLK1
	.IOT TTI,A
	CAIE A,175
	JRST STBLK4
	JRST BEGIN

GWRD:	PUSHJ P,GETDSK
	MOVE C,A
	PUSHJ P,SEND
	PUSHJ P,GETDSK
	PUSHJ P,SEND
	LSH A,8.
	ADD C,A
	POPJ P,

STBLK2:	PUSHJ P,GWRD
	PUSHJ P,GETDSK
	PUSHJ P,SEND
	MOVEI A,0
	PUSHJ P,SEND
	AOSG PASS
	JRST PASS2		;NOW FOR THE REAL STUFF
	.VALUE [ASCIZ /:LOGOUT 
/]

SENDCH:	TRNN F,40
	TRO F,100
	.IOT TTO,F
	POPJ P,

SEND:	JRST @SENDD(B)
SENDD:	SEND1
	SEND2
	SEND3

SEND1:	MOVE F,A
	MOVEI S,0
	LSHC F,-2
	LSH S,-30.
	AOS B
	JRST SENDCH

SEND2:	MOVE F,A
	ANDI F,360
	LSH F,-4
	ADD F,S
	MOVE S,A
	ANDI S,17
	LSH S,2
	AOS B
	JRST SENDCH

SEND3:	MOVE F,A
	LSH F,-6
	ADD F,S
	MOVE S,A
	PUSHJ P,SENDCH
	MOVE F,A
	ANDI F,77
	MOVEI B,0
	JRST SENDCH


	END BEGIN