This is a hardware realization of Eric Smith's Nonpareil microcode simulator.
The objective of the project is to re-create popular 70's RPN calculators such as the HP Woodstock and Spice series.
Another goal of this project is to have the design as simple as possible so that the project can be re-produced by the average electronic hobbyist.
A low power MSP430G2553 is used in this project. The DIP profile allows easy soldering. Only through-hole components are used. LED multiplexing is done w/ a 74hc164 shift register. LED modules are direct driven w/ pulsing to eliminate the need of current drivers.
LED modules are used to mimic the original 70's calculators and gives a retro look to the end product.
press-n-hold 1st row, 5th column (from top) for hp33C
press-n-hold 2nd row, 5th column for hp25C
press-n-hold 3nd row, 5th column for hp21
press-n-hold 4th row, 4th column for version info
press-n-hold 1st row, 4th column to show greetings
press-n-hold 1st row, 3rd column to edit greetings, use 0-9 to enter numbers and letters, Run/Stop to advance digit, Cls to abandon entry
press-n-hold Pgm/Run toggle button to edit default startup settings, use 'F' key to select rom, 'G' key to select speed, Pgm/Run will save setting and exit setup