RPN83P: RPN calculator for TI-83+ TI-84+ inspired by HP-42S

[bxparks]

I just released version 0.7.0 of RPN83P, an RPN calculator app for the TI-83 Plus and TI-84 Plus calculators, inspired mostly by the HP-42S, with significant features from the HP-12C, and HP-16C. I am probably heading towards a v1.0 milestone release in a couple of months. I would appreciate any feedback from users who may notice things that I may have overlooked.

The program is written in Z80 assembly language. It consumes 2 pages (32 kiB) of flash memory. The project home page has screenshots.

Project Home: https://github.com/bxparks/rpn83p

Installation:

• Download the rpn83p.8xk file from the RPN83P Releases page.
• Upload the file to the TI-83 Plus or TI-84 Plus calculator.
• Run the program using the APPS button and selecting "RPN83P".
  

Exiting:

• Quit app: 2ND QUIT
• Turn off device: 2ND OFF
  

Features [Updated on 2024-03-31 for v0.10.0]:

• traditional 4-level RPN stack (X, Y, Z, T) with LastX register
• 8-line display showing all stack registers
• hierarchical menu system similar to HP-42S
• quick reference HELP menu
• storage registers
  
  • store and recall:STO nn, RCL nn
  • storage arithmetics: STO+ nn, STO- nn, STO* nn, STO/ nn, RCL+nn, RCL- nn, RCL* nn, RCL/ nn
  • 25 storage registers: nn = 00..24
  • 27 single-letter variables (nn = A..Z,Theta)
    
• support for all math functions with dedicated buttons on the TI-83 Plus and TI-84 Plus
  
  • arithmetic: /, *, -, +
  • algebraic: 1/X, X^2, SQRT
  • transcendental: ^ (i.e. Y^X), LOG, 10^X, LN, e^X
  • trigonometric: SIN, COS, TAN, ASIN, ACOS, ATAN
  • constants: pi and e
    
• additional menu functions:
  
  • arithmetic: %, %CH, GCD, LCM, PRIM (prime factor), IP (integer part), FP (fractional part), FLR (floor), CEIL (ceiling), NEAR (nearest integer), ABS, SIGN, MOD, MIN, MAX
  • algebraic: X^3, 3RootX
  • transcendental: XRootY, 2^X, LOG2, LOGB, E^X- (e^x-1), LN1+ (log(1+x))
  • trigonometric: ATN2
  • probability: PERM, COMB, N!, RAND, SEED
  • hyperbolic: SINH, COSH, TANH, ASNH, ACSH, ATNH
  • angle conversions: >DEG, >RAD, >HR, >HMS, >REC, >POL
  • unit conversions: >C, >F, >hPa, >inHg, >km, >mi, >m, >ft, >cm, >in, >um, >mil, >kg, >lbs, >g, >oz, >L, >gal, >floz, >kJ, >cal, >kW, >hp
    
• statistics and curve fitting, inspired by HP-42S
  
  • statistics: Sigma+, Sigma-, SUM, MEAN, WMN (weighted mean), SDEV, SCOV, PDEV, PCOV
  • curve fitting: Y>X, X>Y, SLOP (slope), YINT (y intercept), CORR (correlation coefficent)
  • curve fit models: LINF (linear), LOGF (logarithmic), EXPF (exponential), PWRF (power)
    
• base conversion and bitwise operations, inspired by HP-16C and HP-42S
  
  • base conversions: DEC, HEX, OCT, BIN
  • bitwise operations: AND, OR, XOR, NOT, NEG, REVB (reverse bits), CNTB (count bits)
  • integer arithmetics: B+, B-, B*, B/, BDIV (divide with remainder)
  • shift and rotate: SL, SR, ASR, RL, RR, RLC, RRC, SLn, SRn, RLn, RRn, RLCn, RRCn
  • carry flag and bit masks: CCF, SCF, CF?, CB, SB, B?
  • word sizes: 8, 16, 24, 32 bits
    
• time value of money (TVM), inspired by HP-12C HP-17B, and HP-30b
  
  • N, I%YR, PV, PMT, FV, P/YR, BEG, END, CLTV (clear TVM)
    
• complex numbers, inspired by HP-42S and HP-35s
  
  • stored in RPN stack registers (X, Y, Z, T, LastX) and storage registers R00-R24
  • computation modes: RRES (real results), CRES (complex results)
  • display modes: RECT, PRAD (polar radians), PDEG (polar degrees)
  • linking/unlinking: 2ND LINK (convert 2 reals to 1 complex, same as COMPLEX on HP-42S)
  • number entry: 2ND i (rectangular), 2ND ANGLE (polar degrees), 2ND ANGLE 2ND ANGLE (polar radians)
  • extended regular functions: +, -, *, /, 1/x, x^2, SQRT, Y^X, X^3, 3RootY, XRootY, LOG, LN, 10^x, e^x, 2^x, LOG2, LOGB
  • complex specific functions: REAL, IMAG, CONJ, CABS, CANG
  • unsupported: trigonometric and hyperbolic functions (not supported by TI-OS)
    
• date functions
  
  • date, time, datetime, timezone, and hardware clock
  • add or subtract dates, times, datetimes
  • convert datetime to different timezones
  • convert between datetime and epochseconds
  • support alternative Epoch dates (Unix, NTP, GPS, TIOS, Y2K, custom)
  • set and retrieve datetime from the hardware clock (84+/84+SE only)
  • display time and date objects in RFC 3339 (ISO 8601) format
    
• various modes (MODE)
  
  • floating display: FIX, SCI, ENG
  • trigonometric computation: RAD, DEG
  • complex computation: RRES, CRES
  • complex display: RECT, PRAD, PDEG
  • SHOW (2ND ENTRY): display all 14 internal digits
    

Missing features (partial list):

• vectors and matrices
• keystroke programming