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public:calculator:guides:dm41x_ladybug_module

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Hints & Tips

DM41X Ladybug Module

Another HP16 emulation

Section One

Section Two

Ladybug more user friendly, if less versatile, HP16 module than the fully-featured HP16 module by Angel Martin. Both have their uses, but for a simple calculator for bit-banging while writing 6502 assembly code Ladybug does everything, with a less convoluted User Interface.

Nice features

  • A “CMP” function akin to 6502 - sets flags in the same way but doesn't change the register(s)
  • Status Flags : C, Z, N and V equivalent to 6502 flags and set in the same way after various operations.
    • Flag 3 = Carry C
    • Flag 1 = Sign N
    • Flag 0 = Zero Z
    • Flag 4 = Overflow
  • 2-complement mode is set with Flag 2
  • Leading Zeros display is set with Flag 5
  • Word Size is set with Shift+R/S
  • Windowing is selected with .
  • Bits can be set/reset with Shift+4 and Shift+5
  • Logic Tests
    • AND Shift+1
    • OR Shift+2
    • XOR Shift+3

John Pumford-Green 23/09/22 13:40

Further Information

public/calculator/guides/dm41x_ladybug_module.1663938486.txt.gz · Last modified: 06/03/25 06:49 GMT (external edit)