If you’re one of the people who has built yourself a Lisp Badge, there’s a new version of the firmware available which updates uLisp to the latest version, 4.1a.
Get the new version from GitHub:
It has many improvements over the previous firmware release, including:
An improvement to the serial interface, to allow you to upload long programs in a single operation without buffer overflows.
The new implementation of symbols introduced in uLisp Version 4.0, using the workspace rather than a separate symbol table.
The register function, which allows you to read the values of the peripheral registers, or write values to the registers.
For details of the register function, and examples, see: Lisp Badge.