No offical Zircom Software Development Kit exists, however the Japanese DataSlim2 (an almost identical device) did have an SDK released. All of the development options have been derived to a greater or lesser extent from that kit (see History for more background).

The Rex 6000 features a z80 processor and the Rex community have therefore developed a number of Software Development Kits that will compile C to z80 code. You will therefore need to able to use (or learn) either C or Z80 assembler to create addins. If using Z80 you will need a more detailed understanding of the addin header format, however if using, one of the existing compiler Software Development Kits much of this will be done automatically.

Your next steps might be to read the Development Kit section, and then perhaps to check out the links to source code for some existing addins. Download and try compiling these under the appropriate Kit. Once you have sucessfully compiled source code to an addin you'll want to read "System Calls" - this provides some documentation of the available calls (note: machine translated from Japanese).

Finally, if you want to develop addins you should definately join the Rex Developer Mailing List: This open mailing list is intended for discussion between developers for the REX 6000. The list is not intended for general REX 6000 discussion. To subscribe to the list, send "subscribe" (without quotes) in the body of a message to rex-6000-developers-request@lists.rex6000.org. You will be required to send a confirmation email before your request is processed.

You can receive the list in digest mode (many messages combined in one daily email) , after being subscribed, send "set digest" (without quotes) in the body of a message to rex-6000-developers-request@lists.rex6000.org