; EXECST.ASM	for the Osborne Executive		George Peace - 2/85
; This program should be placed on the "A" drive in user zero if the
; expanded CP/M Plus CCP (CCP+) is on the boot diskette.
; This program (or at least the code presented) must be executed prior to
; the first execution of the CCP on the first warm boot.  Osborne - in its
; usual short-sighted wisdom - forgot to count the number of sectors
; available on the boot disk for the CCP.COM file.  There are 4 physical
; sectors of 1024 bytes available (32 sectors) on the disk.  The cold boot
; code loads all 32 to bank 0, address 0.  The warm boot transfers only the
; first 25 from bank zero to bank 1.  This never appeared as a problem
; until someone decided to expand the CCP beyond 25 sectors (i.e. CCP+).
; This code takes advantage of the first-pass warm boot logic in the
; Executive to allow BIOS modification immediately prior to first transfer
; of the CCP to the TPA.  It simply changes a 0Ch to 0Fh to allow a greater
; number of bytes to be transferred from bank 0 to bank 1.
;
	ORG	100H

START:
	LHLD	1		;get warm boot vector address
	INX	H		;move up to routine start address
	MOV	A,M		;get low order byte of address
	ADI	41H		;add offset into WBOOT routine
	MOV	E,A		;save low order byte
	INX	H		;increment to high order byte
	MOV	D,M		;save high order byte
	XCHG			;move the computed address to from DE to HL
	MOV	A,M		;get the high order byte of the CCPLEN value
	CPI	0CH		;is it 0Ch?
	JNZ	0		;nope - take no chances
	MVI	A,0FH		;yup  - load up register A with 0Fh
	MOV	M,A		;and replace the byte in BIOS
	JP	0		;now do a warm boot and (hopefully) load CCP

	END