Key 
Commands 

Power off/on 

R 
Use radians (2p) for trigonometric functions 
GRA 
Use grad (400) 
G 
Use degrees (360) 


normal 
n/a 
SST: In programming mode display next program
step.
Strange things happen when stepping forward beyond the end of the program. 
shiftF 
5C XX 
JP X<0: Programming instruction:
If X<0 then continue normally, otherwise jump to 2digit program address
that follows 
shiftK 
C0CF
(C0C_) 
JPI x<0: Programming instruction:
If X<0 then continue normally, otherwise jump to 2digit program address
that is stored in the specified register. If register number is 03 then
the register is decremented as well. 


normal 
n/a 
BST: In programming mode display previous program step.
Strange things happen when stepping backwards beyond. 
shiftF 
5E XX 
JP X=0: Programming instruction:
If X=0 then continue normally, otherwise jump to 2digit program address that
follows 
shiftK 
E0EF
(E0E_) 
JPI X=0: Programming instruction:
If X=0 then continue normally, otherwise jump to 2digit program address that
is stored in the specified register. If register number is 03 then the register
is decremented as well. 


normal 
52 
RTN: In calculator mode: Set program counter to 00.
In program mode: Returns from subroutine or goes to address 0 if no subroutine
call is pending. 
shiftF 
59 XX 
JP X>=0: Programming instruction:
If X>=0 then continue normally, otherwise jump to 2digit program address
that follows 
shiftK 
909F
(909_) 
JPI X>=0: Programming instruction:
If X>=0 then continue normally, otherwise jump to 2digit program address
that is stored in the specified register. If register number is 03 then the
register is decremented as well. 


normal 
50 
R/S: In calculator mode: Continue program from current address or stop
running program.
In program mode: Halt program. 
shiftF 
57 XX 
JP X<>0: Programming instruction:
If X<>0 then continue normally, otherwise jump to 2digit program address
that follows 
shiftK 
707F
(707_) 
JPI X<>0: Programming instruction:
If X<>0 then continue normally, otherwise jump to 2digit program address
that is stored in the specified register. If register number is 03 then
the register is decremented as well. 


normal 
40  4F
(404_) 
RCL: Recall register 09 or ae and push into X.
The letters "a""e" are printed below 5 keys at the lower end of the keyboard. 
shiftF 
5D (5G) 
DSNZ0: Programming instruction: If register 0 is >=2 then it is
decremented and execution jumps to the address that follows. If register
0 is <2 then it is not decremented and execution continues normally. 
shiftK 
D0DF
(G0G_) 
RCLI: Indirect recall using the register number that follows. If register
number is 03 then the register is decremented after the recall. 


normal 
60  6F
(606_) 
STO: Store X in variable register 09 or ae.
The letters "a""e" are printed below 5 keys at the lower end of the keyboard. 
shiftF 
5B 
DSNZ1: Programming instruction: If register 1 is >=2 then it is
decremented and execution jumps to the address that follows. If register
1 is <2 then it is not decremented and execution continues normally. 
shiftK 
B0BF
(L0L_) 
STOI: Indirect store using the register number that follows. If register
number is 03 then the register is decremented after the store. 


normal 
51 XX 
JP: Programming or calculator mode: Jump to address that follows. 
shiftF 
58 
DSNZ2: Programming instruction: If register 2 is >=2 then it is
decremented and execution jumps to the address that follows. If register
2 is <2 then it is not decremented and execution continues normally. 
shiftK 
808F
(808_) 
JPI: Indirect jump using the register number that follows. If register
number is 03 then the register is decremented after the jump. 


normal 
53 XX 
GSB/SST: In calculator mode: Peform one program step.
In programming mode: Perform subroutine call to address that follows. Use
the "B/O" command to return from a subroutine. 
shiftF 
5A (5) 
DSNZ3: Programming instruction: If register 3 is >=2 then it is
decremented and execution jumps to the address that follows. If register
3 is <2 then it is not decremented and execution continues normally. 
shiftK 
A0AF
(0  _) 
GSBI: Indirect subroutine call using the register number that follows.
If register number is 03 then the register is decremented after the call. 


normal 
07 
Number 7 
shiftF 
1C 
Sine of X 
shiftK 
34 
INT: Integer part of X 


normal 
08 
Number 8 
shiftF 
1D (1G) 
Cosine of X 
shiftK 
35 
FRAC: Fractional part of X 


normal 
09 
Number 9 
shiftF 
1E 
Tangent of X 
shiftK 
36 
Replaces X with the higher value of X and Y. Does not drop the stack.
Warning: If X or Y is 0 then the
result is always 0! Maybe a bug. 


normal 
11 
Substract YX 
shiftF 
21 
Square root of X 
shiftK 
27 
Undefined function. Causes ERROR 


normal 
13 
Divide Y/X. Note that when dividing by 0 the display will go blank for
about 5 (!) seconds before the error condition is displayed. 
shiftF 
23 
Reziprocal of X 
shiftK 
29 
Undefined function. Causes ERROR 


normal 
04 
Number 4 
shiftF 
19 
Inverse sine of X 
shiftK 
31 
ABS: Absolute value of X 


normal 
05 
Number 5 
shiftF 
1A (1) 
Inverse cosine of X 
shiftK 
32 
SIGN: Signum of X: 1 if X<0, 0 if X=0, 1 if X>0 


normal 
06 
Number 6 
shiftF 
1E 
Inverse tangent of X 
shiftK 
33 
HHM: Convert decimal hours to hours.minutes 


normal 
10 
Add Y+X 
shiftF 
20 
Number pi=3.1415... 
shiftK 
26 
HMH: Convert hours.minutes to decimal hours
Example: 2.3030 > 2.505 


normal 
12 
Multiply Y*X 
shiftF 
22 
Sqare of X 
shiftK 
28 
Undefined function. Causes ERROR 


normal 
01 
Number 1 
shiftF 
16 
Exponential of X 
shiftK 
55 
No function 


normal 
02 
Number 2 
shiftF 
17 
Logarithm base 10 of X 
shiftK 
56 
No function 


normal 
03 
Number 3 
shiftF 
18 
Natural logarithm of X 
shiftK 
30 
HHMS: Convert decimal hours to hours.minutes/seconds 


normal 
14 
Swap X and Y stack register 
shiftF 
24 
X to the power of Y. This is reversed comapred to the "normal" mode! 
shiftK 
2A (2) 
HMSH: Convert hours.minutes/seconds to decimal hours
Example: 2.3030 > 2.508333 


normal 
0E 
Push stack (ENTER) 
shiftF 
0F (0_) 
LastX register 
shiftK 
3B (3L) 
RND: Create a random number 0<=X<1 


normal 
00 
Number 0 
shiftF 
15 
10 to the power of X 
shiftK 
54 
Programming instruction: NOP (no operation) 


normal 
0A (0) 
Decimal point. Note that a digit must be entered before the decimal
point! Also, the programming instruction "EXP ." seems to do surprising things. 
shiftF 
25 
Rotate stack down. 
shiftK 
37 
Perform binary operation Y AND X 


normal 
0B (0L) 
Change sign of X 
shiftF 
n/a 
Normal calculator mode (switches out of programming mode). 
shiftK 
38 
Perform binary operation Y OR X 




normal 
0D (0G) 
Clear Xregister 
shiftF 
n/a 
Apparently clears the prefix key. Note that the prefix keys override
each other. So in order to clear the K prefix key press F and then CF. 
shiftK 
3A (3) 
Perform binary operation NOT X 
