Article 1587 of comp.sys.handhelds:
Path: en.ecn.purdue.edu!pur-ee!mentor.cc.purdue.edu!purdue!mailrus!cs.utexas.edu!yale!mintaka!ogicse!plains!harlow
From: harlow@plains.UUCP (Jay B. Harlow)
Newsgroups: comp.sys.handhelds
Subject: 'New' Functions for hp42s
Message-ID: <3842@plains.UUCP>
Date: 22 Mar 90 18:11:47 GMT
Reply-To: harlow@plains.UUCP (Jay B. Harlow)
Organization: North Dakota State University, Fargo
Lines: 109


Hello,
   With the advent of the hp48sx, i got looking on my 42s, boy guess what
i found!

the memory scanner..... (gee why not on the hp28?

'debugging' features:

	key		function
	on-sqrt(x)	reset 
	on-log		single tests (see below)
	on-ln		continuous tests
	on-sum+-xeq	memory  clear!

Single tests:
	key		test
	sum+		SPD ??
	1/x		BEEP
	sqrt(x)		DISPLAY, 7 'steps' of any key
	log		ROM
	ln		DRAM
	xeq		URAM
	sto		KeyBoard, need to press from upper-left to lower-right
			sum+, 1/x, sqrt(x)...... . r/s, +
	rcl		ESD ??
	rdn(pi)		ok message
	backspace(clear)	MEMORY SCANNER!!!!!! ;-)))

Memory Scanner:
	key		function
	up-arrow	+1000h nybbles
	dn-arrow	-1000h nybbles
	div-key		-100h
	mul-key		+100h
	-		-1h
	+		+1h
	cos		+16h, xmit on infrared??? (no printer to check)
	0-9,a-b		enter a digit into memory, +1h (like base app)
	.		execute address in ROM???
	backspace	refresh

Addresses:

	40000-4020c	display
	4020c-40xxx	status line
	50000		memory
	503f6, 2	len alpha reg
	502f8		alpha reg
	50082		last key ??
	50084		key buffer head, tail 
	50086		16 byte key buffer
; table of 5 nybble ptrs
	500b8		ptr to top of stack, 
			this is indirect, & points to last byte of stack,
			go left or lower in memory
			CAN HAVE MORE THAN ST X, ST Y, ST Z, ST T, ST L
	500d6		ptr to program end?
	500db		ptr to REGS var, & rest of var list

; inst table?  
;	nybble len
;	str	name
;	addr	address?	; 5 nybble address????

	1db62		ABS
	1e8a8		XFCN
	1e9fa		[MIN]
	1ea2d		'TED4ME' ??? looks like a function but no work....
	1ea3f		'DDST X'

;	i have a whole list of em, but to lazy to type em in.....

'New' instuctions.....

	XFCN str	wants a program label?, needs something else
			always says 'Nonexistent'

	[FIND]		find a value in an array.
			01 INDEX "REGS"		; look in this array
			02 2			; number to look for
			03 [FIND]		; look for a 2 (ST X)
			04 RCLIJ		; where found

	[MIN]		find the minimum in array
	[MAX]		find the maximum in array
			this two look in a single column
			returns: ST Y - row where found
				 ST X - value 

			01 3
			02 ENTER
			03 DIM "AA"		; a sqauare 3x3
			04 1			; starting row
			05 3			; column
			06 STOIJ		; look in third column
			07 [MIN]		; or [MAX]

Well for now thats enough?

	Hope you enjoy these new findings,
	
		Jay B. Harlow
			
-- 
		Jay B. Harlow	<harlow@plains.nodak.edu>
	uunet!plains!harlow (UUCP)	harlow@plains (Bitnet)

Of course the above is personal opinion, And has no bearing on reality...