Hi everybody! I'm new here I'm starting to learn z80 assembly for the ti 83+. I was wondering if it would be possible to build your own calculator with a z80 microprocessor and some sort of screen similar to the ti calculators screen. Wouldn't you have to put the ti-os on it to run programs and such? If this is even possible we could probably add more memory to the home made calculator. Unless that would cause you to have to rewrite the ti os or something to support more memory. I don't know if this is just stupid or if some one has asked before. But all feedback is appreciated!  (Sorry if this is dumb or impossible)

It's definitely possible. I am currently working on a z80 computer. My current design could be miniaturized to calculator size if I switched over to smd and replaced the many 74 series ics with an fpga or a microcontroller. To run programs, right now I flash a 32k eeprom and use 32k ram. I'm probably going to add bank switching soon. If you want to start making circuits with the z80, take a look at z80.info.

Hrm, I'd rather want to make a "calculator" with only a d-pad, about 4 buttons and something like MirageOS as -actual- os in stead of a shell. Just for playing games, like some cheap Chinese handheld

You just gave me idea.

I should so make one then give directions so everyone on Omni can make one and then we all make games for them and share game ideas and then our game system is better then Nintendo and we make monies off of our idea

Hey camnedmil are you by any chance this guy? http://benryves.com/projects/z80computer

Ben Ryves is actually the member called Ben Ryves

1) yeah... Ben wouldn't really sign up in another name, considering no one else has that name yet, and it's his name everywhere else.

2) this is in the wrong forums section

3) for adding memory, why not use msd8x?  Building a whole new calculator seems.. rather unnecessary.

Well a new calc would be nice in the way it could offer more than TI's while still costing less. That was OTZ80 goal to offer more for less, so people aim for compatible z80 calcs (a TI-84+ emu was planned) while not having to spend $110 for 1970 hardware. However such project is a huge undertaking, so be warned that it will be a lot of work and be complicated.

On a side note welcome on the forums kingofthebacon.

A z80 is only about $5.  You can get a better LCD screen for about $15.