TITLE	NULSEG - DUMMY HIGH SEGMENT ROUTINES FOR MACHINE WITH JUST ONE REG - V406
SUBTTL	T.HASTINGS/TH   TS  2 JUNE 69
XP VNULSG,406
		;PUT VERSION NUMBER IN LOADER STORAGE MAP AND GLOB LISTING

	ENTRY NULSEG
NULSEG:			;ENTRY POINT SYMBOL TO CAUSE LOAD OF NULSEG IF REQUIRED
			;(IE INSTEAD OF SEGCON OR NEITHER)

;INITIALIZE LOC TWOREG TO 0(FLAG SOFTWARE OR HARDWARE ONLY 1 REG CAPABILITY)
;AND1 AND2RG EXECUTED FROM ONCE AFTER HARDWARE EXAMINED FOR 2 REG CAPABILITY.

	INTERN AND2RG

AND2RG=0	;FLAG SYSTEM DOES NOT HAVE 2 REG. CAPABILITY
		;SINCE AT LEAST SOFTWARE DOES NOT BECAUSE THIS DUMMY
		;ROUTINE LOADD

;CLOCK1

	INTERN SETHGH

SETHGH:	TLZ PROG,1777	;CLEAR OUT PROTECTION FOR HIGH SEG IN CASE THIS
	POPJ PDP,	;IS A 2 REG MACHINE

XP CHGHGH,R0		;CHARGE CURRENT USER FOR HIGH SEG

;COMCSS

XP PRTHGH,R0		;PRINT HIGH SEG CORE
XP ASGHGH,R0		;CLEAR HIGH SEG NAMES ON ASSIGN COMMAND
XP CHKMED,R0		;CHECK FOR MEDDLING
XP ANYSAV,R1		;NAY JOB DOING A SAVE INVOLVING HIGH SEG?
;CORE1

XP HGHDEP,R0		;DEPOSIT HIGH SEG(ERROR)
XP KILHGH,R0		;REMOVE HIGH SEG FROM LOGICAL ADR SPACE
XP UREMAP,R0		;REMAPO UUO
XP CURHGH,R0		;CHANGE RELOC HARD IF CURRENT USER AFFECTED
XP FRECOR,R0		;FREE CORE IN NON-SWAP SYSTEMS
XP FRECR1,R1		;FREE CORE IN SWAPPING SYSTEMS

	INTERN UCORHI,SUMSEG
	EXTERN CORMAX,USRREL

UCORHI:	CAMLE TAC,USRREL	;TRYING TO ASSIGN CORE TO HIGH SEG?
	POPJ PDP,		;YES, ERROR RETURN
				; NO, GIVE OK RETURN
SUMSEG:	CAMGE TAC,CORMAX	;ARG GE MAX LENGTH (HIGHEST+1)?
R1:	AOS (PDP)		;NO, GIVE OK RETURN
R0:	POPJ PDP,		;YES, GIVE ERROR RETURN

;ERRCON

XP SEGILM,R1		;WILD TRANSFER RETURN

;SAVGET

XP SETEXT,R0
XP SETEX1,R0
XP SAVDDL,R0		;DIDDLE RELOC, DURING DUMP MODE O/P FOR HISEG

	INTERN UGETHI
	EXTERN UGTERR

UGETHI:	JRST UGTERR		;ERROR RETURN TO USER UNLESS HALT IN LH OF UUO+1

	INTERN SAVHGH,GETHGH
	EXTERN SGERRA,SGAMOD,SG3

SAVHGH:
GETHGH: OPEN 0,SGAMOD		;TRY TO INIT DEVICE
	JRST SGERRA		;ERROR
	AOS (PDP)		;SKIP RETURN
	JRST SG3		;AND GO SETUP LOWER CORE
;SWAP

	INTERN FTSWAP

IFN FTSWAP,<
XP FININ,R1		;FINFISH SWAPPING IN
XP FINOT,R1		;FINISH LOW SEG OUTPUT - NOTHING MORE TO DO
XP FORSIZ,R0		;SIZE OF JOB FREED UP
XP FRESWP,R1		;FREE DISK SPACE - NO DORMANT SEG FOUTND RETURN
XP FITHGH,R0		;CHECK IF HISEG BEING SWAPPED IN

	INTERN FITSIZ
	EXTERN CORTAL

FITSIZ:	CAMG AC1,CORTAL		;WILL LOW SET FIT IN CORE?
	AOS (PDP)		;YES, SWAP HIM IN
	POPJ PDP,		;NO, MUST SWAP SOMEONE ELSE OUT FIRST	

	INTERN FORHGH
	EXTERN JBTSTS

FORHGH:	MOVSI TAC,SHF	;STOP IO AFTER NEXT BUFFERFUL IF ACTIVE
	IORM TAC,JBTSTS(ITEM)	;CHECKED BY ADVBFF,ADVBFE ROUTINES
	POPJ PDP,
>

;SYSINI

XP SEGINI,R0		;INITIALIZE HIGH SEGS

;UUOCON

XP RELSEG,R0		;SUPERCEDE HIGH SEGS ON RECREATE
XP RELSG1,R1		;RENAME UUO
XP HGHWRD,R0		;GET WORD FROM HIGH SEG - ERROR RETURN
XP HRESET,R0

	INTERN USTUWP
	EXTERN RTZER

USTUWP:	JRST RTZER

XP HGHWRD,R0		;GET WORD FROM HIGH SEG -ERROR
XP USPY,R0		;SPY UUO - ERROR


	END