Calypsi tool chains

Overview of the Calypsi tool chain and open source support packages

Calypsi tool chains

Calypsi is a series of C compiler and assembly language cross compiler tool chains. The current tool chains are aimed towards the retro and hobby communities. Future products will be for typical targets used in embedded programming.

Supported targets and platforms

Latest release is 5.4 available here for the following targets:

Supported host platforms are:


Allowed use

The tools are closed source. You can use them free of charge for hobby purposes, which means you are not allowed to make your living based on using the tools, either directly or indirectly.

Having a small side or hobby based income from using the Calypsi tools is permitted.

An exception to the above is given to the HP-41 Nut target which is provided with a BSD license to its binary distribution. Permission is given to use the HP-41 Nut tools for commercial use, free of charge.

Feedback and issues

If you cannot find a suitable project below to post questions or report issues in, feel free to do it in this project.


If you feel need to reach me directly you can do so by sending e-mail to


Donations to help me work on this code base is very much appreciated. If you feel that you want to help you can do so by using Paypal to This is by no means mandatory, you are free to use the tools regardless, as mentioned above.

MOS 6502 target

The 6502 target supports the MOS6502, WDC65C02 and 45GS02 processors.

Open source projects

WDC 65816 target

The 65816 target supports the WDC65816 processor.

Open source projects

Motorola 68000 target

The 68000 target supports the Motorola 68000 processor.

Open source projects

HP Nut target

The Nut target supports the HP-41 Nut and NEWT processors.

Open source projects