;*************************************************************************
;
;   File:               EinSys_boot.txt
;
;   EINSYS - This code is entered by hand via the Einstein MOS and as such
;   should be as short as pos. The size of the utility program to be 
;   transferred, which can't call DOS, is currently fixed (this could be
;   be changed to be the first two bytes transferred if necessary).
;		
;
;*************************************************************************

		CPU Z80

EINSYS_ADDR	EQU $0100		; address where program will be download
EINSYS_EXEC	EQU $0100		; entry address of program
EINSYS_SIZE	EQU $0800		; size of program

		ORG $1000


MAIN		LD	A,%00100111
		OUT	($11),A
!reset		IN	A,($10)
		IN	A,($11)
		BIT	1,A
		JR	NZ,!reset
		LD	A,%00000111
		OUT	($11),A
		; read bytes from PC
		LD	HL,EINSYS_ADDR
		LD	DE,EINSYS_SIZE
!loop		LD	A,%00100111
		OUT	($11),A
!get		IN	A,($11)
		BIT	1,A
		JR	Z,!get
		IN	A,($10)
		LD	(HL),A
		LD	A,%00000111
		OUT	($11),A
		INC	HL
		DEC	DE
		LD	A,E
		OR	A,D
		JR	NZ,!loop
		; start EINSYS proper
		JP	EINSYS_EXEC
MAIN_END

		INF "Main runs from ",MAIN, "-",MAIN_END

		MEMSAVE "EinSys.bin",MAIN,MAIN_END


; end of file