Message #1 Posted by Klaus on 22 Aug 2004, 1:25 p.m.
Who is currently building an emulation of the HP-41? (Nelson?)
If noone is, I will do that (or we can do it together).
As there are nice simulations written in C/Cpp, our microcontroller should be supported by a (free) C-Compiler.
LCD: I currently donīt have any experience with LCDs, but those with a built-in controller are easy to use (according to datasheets).
Which LCD and microcontroller can be used? On the PIC, the Interpreter takes about 3000 asm-instructions, plus 1000 asm-instructions for i/o, main loop and i2c communication.
Speed: On the PIC with 4mHz, the emulation of the hp-45 has about the same speed as the original hp-45 (I think it has 380 kHz). But since the LEDs are updated every main-loop cycle, a LCD should speed up things.
Pins: 8 for the keyboard and 8 for display plus a few for RS232/USB
HP41-firmware in program memory or eeprom?
My plan is to take a simulation of the HP-41** (either nonpareil or the one from "TOS"), move the interpreter part to our microcontroller, add i/o and debug debug debug.
So any suggestions for the microcontroller or LCD?