'New' Functions for hp42s
Jay B. Harlow
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 <har...@plains.nodak.edu>
uunet!plains!harlow (UUCP) harlow@plains (Bitnet)
Of course the above is personal opinion, And has no bearing on reality...
W.A.C. Mier-Jedrzejowicz
Most of what Jay describes has already been covered on
comp.sys.handhelds, on the HPHH echo in FidoNet, and in user club
magazines, but there are always new readers who have not seen the
earlier postings, so there is no harm in posting again. My point in
writing this is to tell keen HP-42S users that the most recent issue of
the journal of the Danish user club has an article IN ENGLISH on just
these HP-42S topics. XFCN is explained there as a command to execute a
machine language function which the user can enter direct into RAM with
the debugger. I submit a list of user club addresses to this area from
time to time, maybe the arrival of the HP 48SX and the subsequent
increase in interest in all HP handhelds means I should submit an
updated address list again. Might I ask anyone who knows of new clubs
or of address changes to send information to me personally, and I shall
post an updated list on comp.sys.handhelds in about a week? Some users
of electronic mail and bulletin boards feel that the Guthenberg
technology is best left to die - but I feel that both technologies have
their uses - a club journal is much more useful on a plane flight or a
train ride than is attempting to download and read a bulletin board
article under those circumstances.
Wlodek Mier-Jedrzejowicz,
Space Physics, Imperial College, London UK,
Disclaimer: my opinions, if they are opinions, are not the opinions of
my employer, if my employer has opinions.
Steffen Seitz
In article <1990Mar24....@cc.ic.ac.uk> uma...@sunb.cc.ic.ac.uk (W.A.C. Mier-Jedrzejowicz) writes:
> ...
> earlier postings, so there is no harm in posting again. My point in
> writing this is to tell keen HP-42S users that the most recent issue of
> the journal of the Danish user club has an article IN ENGLISH on just
> these HP-42S topics. XFCN is explained there as a command to execute a
------------
> machine language function which the user can enter direct into RAM with
------------------------------------------------------------------
> the debugger. I submit a list of user club addresses to this area from
> ...
Does a detailed description of XFCN (alias SYSEVAL ?) voilate any copyright
restrictions? The 4-5 HP-42 owners (including me) reading c.s.h would be
full of gratitude !!! ;-).
--
== Steffen Seitz (se...@infotue.uucp, +49 07071/29-5459) =====================
== Universitaet Tuebingen, Wilhelm-Schickard-Institut fuer Informatik ========
== Auf der Morgenstelle 10C, 7400 Tuebigen, West Germany =====================
Bruce Stephens
It is totally useless in any machine covered under HP's warranty. It
could possibly be used if some machine happened to have a static RAM
or an EPROM accidently stuck onto its circuit board and a trace or two
broken or solder-bridged on the circuit board.
If such a calculator happened to have this configuration, it would
have memory at address 20000 (hex). In a really bizzare twist of
fate, if the first five nibbles at that address happen to be F3CA5,
the HP-42S will not give the usual "Nonexistent" error. Instead, the
CPU will do a subroutine jump to address 20005 (hex) and execute
whatever assembly level code happens to be there. It is possible that
this code could even look at the value of the mysterious parameter to
XFCN and do different things based on its value.
All of this would be fairly difficult given that this is a "closed"
machine, whose internals are not documented or supported by HP.
Bruce Stephens
Kevin Routh x622
I saw the message from Steffan Seitz for HP-42S owners. I too
own one of those great little machines and am a new subscriber to the
"News" network. I have owned my calculator for nearly 1.5 years and
have missed out on all the stuff which has appeared on "News" during
that period. Could you tell me how to get ahold of what I missed? All
the messages (except yours) deal with the 28S or the new 48SX. Thanks
for your help. It's sure a great little machine.
Kevin Routh (ro...@eltanin.rtp.semi.harris.com)
Harris Smart Power Products
Durham, North Carolina, USA 27709