Hi. Going from memory here but believe that the older multi-uart code was a module based IP. That is, XMOS was for a long time, supporting stand alone building blocks of canned s/w IPs to bit-bang out whatever you wanted (ie. UART, Ethernet, TCP/IP, LCD display, etc.). Then the shift was made to the library model and the 3.1.0 is the current UART library IP and also is maintained by XMOS staff.
https://www.xmos.com/support/libraries/lib_uart
However, if the older code is practical for your usage, by all means proceed. The older XMOS processors were the XS1 core and the XCORE-200 series is backwards compatible with XS1 but with more features.
On the multi-uart IP:
http://xcore.github.io/sc_multi_uart/index.html
https://github.com/xcore/sc_multi_uart
Details of the required packages are posted here:
http://xcore.github.io/sc_multi_uart/Ex ... stallation
Now on the issues you are facing in technically using the older slice boards with the newer XCORE-200 platform:
a) it should be possible to use the referenced boards but do pay attention to the graphic symbols on the main slice kit and also your slice boards. For example, if the small slice board features a square and triangle graphic (just some random symbols for this discussion) then you can ONLY use the respective PCI Express edge connector on your slice kit with these graphics. Then you must apply the respective pins that are only present for that graphic for your project source code. Hope this makes sense - write back if it does not.
b) do note that some of the PCIe slots may be bonded to Tile # 0 (ie. X0 prefix) vs. Tile # 1 (ie. X1 prefix) for the port names. This can be a real life sucking experience if you miss this critical detail. As a sanity check, consider to pulse a port pin of your liking that is bonded to the PCIe slot you plan to use @ 1 Hz or so. Then run and look for this pulsing pin on the PCIe slot. Proceed only if you can confirm this operation else you are shooting blanks :)
We are not audio developers (yet) but rather communication guys so may be wrong here but believe the audio IP you are after for your audio slice testing is posted here:
https://github.com/xcore/hw_slicekit_sy ... A-SK-AUDIO
Here is the main link for the older XS1 based SliceKit which we have here in the lab (we do not yet own the XCORE-200 slice kit):
https://github.com/xcore/hw_slicekit_system
Hope this helps. Write back if you have other questions and will try to assist where possible.