HP HP-41CV Service manual

HP-41CV
HP-41CV Quick Reference
 A. Thimet
Overview
←RUN mode: Clear last entered digit ot entire X-register
PRGM mode: Delete currently displayed program instruction
USER Turn user mode on off. In user mode, every key can possibly be
programmed to perform some specific internal or programmed function. See
the ASN command.
PRGM Turn programming mode on off.
Use „GTO ..“ to pack program memory and jump to the beginning of unused
space. In PRGM mode „00 REG nn“ will be displayed where nn is the
number of available registers for program data.
ALPHA Turn ALPHA (string entry) mode on off.
On the back of the calculator is a list of charcters that can be reached by the
yellow prefix key.
Memory 319 registers. Initially 46 registers are program space and 273 registers are
available for variable storage.
One register can approximately hold 6 program steps, so initially there are
276 program steps available. When the number of storage registers is
reduced to 10 using „SIZE 010“ then 309 registers are available for
programs corresponding to 1854 program instructions.
Available
functions
Use the CAT command to get a list of internal and external functions.
Use XEQ ALPHA <name> ALPHA to execute a command which is not
directly available on the keyboard.
Use the same sequence to enter such commands in a program!
Indirect
addressing
See RCL command
Command Reference
+Add Y + X → X
-Subtract Y – X → X
xMultiply Y * X → X
Divide Y X → X
1 x Reciprocal value
10↑xExponential function base 10
ABS Absolute (positive) value of X
ACOS Inverse Cosine using current trigonometry mode
AOFF ALPHA mode off
AON ALPHA modem on. Using the SHIFT key various special keys and functions
can be accessed. See on the back of the calculator.
The ALPHA register can hold up to 24 characters.
PRGM mode: A program line can only hold at most 15 characters. To put a
longer string into the ALPHA register use two program lines and start the
second one with “SHIFT K” which is the APPEND command
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HP-41CV
ARCL Append the value of the data register nn to the ALPHA register. A data
register or a stack register can hold at most 6 characters. Note that if ALPHA
data is stored in a data or stack register the ALPHA mode of the data will be
preserved. An error occurs if a numerical function is executed on ALPHA
data.
See RCL for indirect addressing modes.
ASHF Shift ALPHA register 6 characters to the left. Left 6 characters are lost
ASIN Inverse Sine using current trigonometry mode
ASN Assign a function or program to an arbitrary key for use in USER mode:
“ASN ALPHA <func name program name> ALPHA <key>”. Or
“ASN ALPHA <func name program name> ALPHA SHIFT <key>” in which
case “SHIFT <key>” executes the command.
To undo the assignment: “ASN ALPHA ALPHA [SHIFT] <key>”
See also command LBL for top-row auto-execution
ASTO Store leftmost 6 characters of the ALPHA register in data register nn. See
RCL for indirect addressing modes. See ARCL for more information on
ALPHA data
ATAN Inverse Tangent using current trigonometry mode
AVIEW Display the ALPHA register until a key is pressed
BEEP Play a fixed short melody
BST PRGM mode: Go to previous program step.
RUN mode: Go to previous program step but do not execute any commands.
CAT CATALOG list functions:
CAT 1: Global program labels. Global programs are separated by END
instructions. Press PRGM to edit the currently listed program
CAT 2: Functions in expansion modules
CAT 3: Built-in functions
CAT 0, 4-9: Same as CAT 3
R S halts the listing, SST shows next entry, BST shows previous entry.
See RCL for indirect addressing modes
CF Clear flag nn. See RCL for indirect addressing modes. Flags are:
00-10: General purpose flags where flags 0-3 are shown in the LCD display.
Can be set reset by the user
11-29: Special purpose flags. Can be set reset by the user. Those sometimes
have a special meaning:
11: Automatic Execution Flag. If set the HP-41C automatically begins
executing the current program whenever the calculators turned on
14: Card Reader Overwrite Flag. When set, flag 14 allows you to overwrite
write-protected cards with the optional card reader
21: Printer Enable Flag. Printing is enabled when this flag is set
22, 23: Data Entry Flags. These two flags detect keyboard input. The
calculator sets flag 22 when numeric data is entered from the
keyboard and flag 23 when alpha data is entered. Both flags are
cleared each time calculator is turned on
24, 25: Range Error And Error Ignore Flags. That these flags control how the
HP-41C reacts to range errors and operating errors. If flag 24 is set
range errors are ignored and numbers such as 9.999999999x1099
are returned in place of errors. Flag 24 remains set until you clear it. If
flag 25 set other errors are ignored. Flag 25 is cleared each time an
error occurs
26: Audio Enable Flag. When set tones are produced
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HP-41CV
27: User Mode Flag. This flag is used to place the calculator in user mode
28, 29: Number Display Control Flags. Flag 28 controls the radix and
separator marks. It may be set for American or European styles.
When flag 29 is set groups of three digits are separated with commas
or points depending on the setting of flag 28.
30-55: System flags. Can only be tested:
30: Catalog Flag. For internal use
31-35: Peripheral Flags. These flags are used internally for the operation of
certain peripherals
36-39: Number Of Digits. These flags are used internally to control the
number of digits displayed
40, 41: Display Format Flags. These flags control the display mode
42, 43: Trigonometry Mode Flags. When flag 42 is set the calculator is in
GRAD mode. When flag 43 a set the calculator is in RAD mode
44: Continuous On Flag. If flag 44 is on the HP-41C will stay on
indefinitely. If it is clear the calculator will turn off after 10 minutes of
inactivity
45: System Data Entry Flag. Used internally and always tests clear
46: Partial Key Sequence. Used internally and always tests clear
47: Shift Set Flag. Used internally and always tests clear
48: Alpha Mode Flag. When the HP-41C is in alpha mode flag 48 is set,
otherwise flag 48 is clear
49: Low Battery Flag. When this flag is set battery power is low. The BAT
annunciator will also show in the display when this flag is set
50: Message Flag. If set, the display contains some message (not the
Alpha or X register)
51: SST Flag. Used internally and always tests clear
52: PRGM Mode Flag. Used internally and always tests clear
53: I O Flag. When set, a peripheral extension is ready for I O. Otherwise
device is not ready for I O
54: Pause Flag. When set a PSE (pause) instruction in a program is in
progress
55: Printer Existence Flag. When set, an HP-41C printer is attached to the
calculator.
CHS Change sign of X
CLA Clear ALPHA register
CLD Clear display and the displayed register (either X or ALPHA)
CLP “CLP ALPHA <prg name> ALPHA” deletes the specified program
“CLP ALPHA ALPHA” deletes the current program
CLRG Clear all data registers
CLΣClear statistics register. See ΣREG
CLST Clear all stack register
CLX Clear X register
COPY Copy a user program
COS Cosine using current trigonometry mode
D-R Convert degrees (360) to radiants (2π)
DEC Convert X register from octal to decimal
DEG Set trigonometry mode degrees (360)
DEL PRGM mode: Delete nnn commands starting with the current one.
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HP-41CV
DSE Decrement and skip if equal or less. „DSE nn“ operates on data register nn
and depending on the test skips or executes the next program line. The data
register must initially be loaded with a value of the form ccccc.tttdd where
ccccc is the current counter value, ttt is the test value and dd is the decrement
value (increment value for the ISG command).
The DSE command will substract dd from ccccc and compare the result to ttt.
If the result is less than or equal to ttt the next program line will be skipped.
See RCL for indirect addressing modes
END Ends a program and separates multiple „global“ prorgams. A global program
can contain multiple „local“ subprograms which end with RTN
ENG Select engineering display format rounded to n+1 valid digits where the
exponent is always a multiple of 3 and the mantissa is ≥1. This does not affect
the internal representation of the number.
See RCL for indirect addressing modes
ENTER↑Push the stack
E↑XExponential function base e
E↑X-1 Calculate (e↑x) – 1, used for very small values of X
FACT Faculty von X (X!). Does not allow for negative or non-integer values.
FC? Check whether flag nn is clear. See CF
PRGM mode: If the condition is true the next program step is executed,
otherwise it is skipped.
RUN mode: The test result is displayed (YES or NO)
FC?C Check whether flag nn is clear and then clear it. See CF
FIX Select fix point display format rounded to n valid digits after the decimal point.
Will automatically switch to SCI format if the number gets too big or too small.
This does not affect the internal representation of the number.
See RCL for indirect addressing modes
FRC Fractional part of X
FS? Check whether flag nn is set. See CF
FS?C Check whether flag nn is set and then clear. See CF
GRAD Set trigonometry mode „grad“ (400)
GTO Go to a label or program line number. Does never execute any program
instructions! See RCL for indirect addressing modes.
RUN mode:
„GTO nn“ goes to the local label 00 – 99 of the current program
„GTO ALPHA <character> ALPHA“ goes to the given local label of the current
program
„GTO ALPHA <name> ALPHA“ goes to the given global label. „name“ may
have up to 7 characters
PRGM mode:
„GTO nn“ inserts a jump instruction to the given local label 00 - 99
„GTO ALPHA <character> ALPHA“ inserts a jump instruction to the given
local label
„GTO ALPHA <name> ALPHA“ inserts a jump instruction to the given global
label. „name“ may have up to 7 characters
PRGM and RUN mode:
„GTO . nnn“ goes to the program line number nnn of the current program
„GTO . EEX nnn“ goes to the program line number 1nnn of the current
program (for program with more than 1000 lines)
„GTO . ALPHA <character name> ALPHA“ goes to the specified local or
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HP-41CV
global label.
„GTO ..“ packs program memory and goes to the unused program memory
area to be able to enter a new program. In PRGM mode „ss REG nnn“ is
displayed where nnn is the amount of available program registers (with about
6 commands per register).
HMS Convert X from decimal to hour min sec (h.mmss) representation
Example: 1.5 HMS results in 1.3000
HMS+ Add Y + X → X in h.mmss format
HMS- Subtract Y - X → X in h.mmss format
HR Convert X from hour min sec (h.mmss) to decimal representation.
INT Integer part of X
ISG Increment and skip if greater. See DSE. See RCL for indirect addressing
modes
LASTX Recall the most recent value of the X register
LBL Enter a local numerical label (00–99), a local character label (A – J and a – j)
or a global character label (2 – 7 characters or a non-local single-character
label) in a program.
In USER mode the program code at a local character label of the current
program can directly be executed by pressing one of the two top row keys. Ie.
pressing “1 x” executes the code at local label “B”. This works for labels “A” –
“J”. Pressing “SHIFT 1 x” executes the code at label “b”. This works for labels
“a” – “j”
Note that if a key has been assigned to a function or program using the ASN
command no local labels are executed.
Local labels are only visible within the current global program.
Warning: You can enter a "global" program that starts with a local label.
However, after the focus moved away from this program (ie. by executing
another program or by executing "GTO..") you cannot easily access this
program!! A GTO to the local label or an XEQ will fail with NONEXISTENT.
Also, it is not possible to use "CLP" to delete the memory occupied by the
program! The only way to move the focus to this "hidden" program is to use
"CATALOG 1" and carefully watch for an "END" that is not preceeded with a
global label. After the listing has been stopped when this "END" is displayed
switching to PRGM mode will display the program and it is possible to delete it
step-by-step to reclaim program memory.
LN Logarithm base e
LN1+X Calculate ln(1+x), used for small values of x
LOG Logarithm base 10
MEAN Mean value of data in the statistics registers. See ΣREG
MOD Modulo (reminder) of division Y X
OCT Convert X register from decimal to octal
OFF Turn calculator off
ON Turn calculator on.
If the „←“ key is held down while turning on a global reset is executed and all
data, stack and program registers as well as user flags are cleared
P-R Convert polar coordinates (X=angle, Y=length) to rectangular coordinates
(X,Y) using current trigonometry mode
PACK Pack the program memory
% Percent. This does not pop the stack
%CH Percentual difference from Y to X. This does not pop the stack
PI π = 3.1415…
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HP-41CV
PROMPT Display the ALPHA register and wait until the user enters a number and
presses R S
PSE Pause the program for a second and display the X register. X can be modified
during the pause and the program will continue if no key is pressed for one
second
R↑Rotate stack up
R-D Convert radiants (2π) to degrees (360)
R-P Convert rectangular coordinates (X,Y) to polar coordinates (X=angle,
Y=length) using current trigonometry mode
RAD Set trigonometry mode radiants (2π)
RCL Get the value of a register to X. Addressing modes:
„RCL nn“ gets value of register nn (00 – 99)
„RCL SHIFT nn“ gets the value of the register which is addressed by register
nn (indirect addressing)
„RCL . r“ gets a stack register where r is one of the keys labelled X,
Y, Z, T or L (without pressing ALPHA)
„RCL SHIFT . r“ gets the value of the register which is addressed by register
r=X, Y, Z, T or L (indirect addressing)
„RCL Σ+“ is the same as „RCL 01“
„RCL 1 x“ is the same „RCL 02“ etc. up to
„RCL TAN“ is the same as „RCL 10“. This also works in USER mode
Registers 00 – 99 can be addressed directly. Higher registers must be
accessed thru indirect addressing.
If the recalled register contains an ALPHA string it will be displayed but it will
not overwrite the contents of the ALPHA register.
If a register contains an ALPHA string it cannot be used for indirect
addressing
RDN Rotate stack down (same as R↓)
RND Round the X register according to the number of valid digits as specified in
the current ENG, SCI or FIX command
RTN PRGM mode: Return to calling program or stop if at the top level
RUN mode: Go to line number 0 of the current program (=“GTO 000“)
SDEV Calculate standard deviation of the data in the statistics registers. See ΣREG
SCI Select scientific display format rounded to n+1 valid digits. This does not
affect the internal representation of the number.
See RCL for indirect addressing modes
SF Set flag nn. See CF
SIN Sine using current trigonometry mode
SIGN Replace X with the sign of X, either +1 or -1
SIZE Specify number of data registers. Ie. „SIZE 050“ reserves space for 50 data
registers (00 – 49) for STO RCL operations. The remaining memory can be
used for programs where one register can approximately hold 6 program
steps.
Storage registers >99 can only be accessed using indirect addressing, see
RCL command.
It is not possible to delete existing programs with the SIZE command. You
may have to erase programs first before memory space can be assigned to
data registers
SQRT Square root
SST PRGM mode: Go to next program step
RUN mode: Execute next program step. The command is displayed when the
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HP-41CV
SST key is pressed and held down
ST+ Add X to data register nn. Same as „STO +“. See RCL for indirect addressing
modes
ST- Subtract X from data register nn. Same as „STO -“. See RCL for indirect
addressing modes
ST* Multiply data register nn with X. Same as „STO *“. See RCL for indirect
addressing modes
ST Divide data register nn by X. Same as „STO “. See RCL for indirect
addressing modes
STO Store X in data register nn. See RCL for indirect addressing modes
STOP PRGM mode: Insert a stop instruction which will halt program execution.
Programm can be continued using R S in RUN mode
Σ+Add data to the statistics registers and replace X with the number of values in
ΣREG. See ΣREG.
Σ-Substract data from the statistics registers and replace X with the number of
values in ΣREG. See ΣREG.
ΣREG Set the base register number for the 6 statistics registers. Ie. „ΣREG 11“ uses
registers 11 to 16 (default):
11: Sum of X values
12: Sum of X*X values
13: Sum of Y values
14: Sum of Y*Y values
15: Sum of X*Y values
16: Number of values
TAN Tangent using current trigonometry mode
TONE Play a tone with a frequency proportional to n (0 – 9). The argument can
indirectly be obtained from a register: „TONE SHIFT 00“ uses the number in
data register 0 as frequency parameter
VIEW Display contents of register nn without overwriting the X register.
Press ← to return to normal stack display.
See RCL for indirect addressing modes
X=0?
X≠0?
X<0?
X<=0?
X>0?
X=Y?
X≠Y?
X<Y?
X<=Y?
X>Y?
Check whether X is 0 and other comparisn operations.
PRGM mode: If the condition is true the next program step is executed,
otherwise it is skipped.
RUN mode: The test result is displayed (YES or NO)
X<> Swap X register with data register nn. See RCL for indirect addressing modes
X<>Y Swap X and Y register
XEQ Execute a built-in function or user program. A maximum of 6 user-subroutines
can be stacked. Ie. „XEQ ALPHA MEAN ALPHA“ calculates the statistical
mean value. See RCL for indirect addressing modes
X↑2Square of X
Y↑XY to the power of X. Y may be negative if X is integer
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