What problem does it solve? Working with the zsdcc compiler in z88dk requires knowing which clib flags to use, how SDCC calling conventions differ from sccz80, and how to regenerate the z88dk-specific patch when the pinned SDCC revision changes. This Skill consolidates that knowledge so builds and patch upgrades are done correctly. ## Core Features & Use Cases - Compiler selection guidance: Explains -clib=sdcc_ix vs -clib=sdcc_iy, newlib integration, and when to prefer sccz80 for 8080/8085/gbz80 targets. - Patch regeneration procedure: Provides a step-by-step workflow for updating src/zsdcc/sdcc-z88dk.patch when the SDCC pin (SDCC_VERSION) changes, including ABI 0 enforcement, version banner, ChangeLog $Revision$ fix, peep special-function table, and tarball packaging for CI. - Use Case: When SDCC releases a new revision, follow the documented procedure to check out the new svn revision, re-apply all required z88dk hunks, verify a clean patch -p0 round-trip, and produce the zsdcc_r<rev>_src.tar.gz tarball for nightly builds. ## Quick Start Ask the assistant to regenerate the zsdcc patch for a new SDCC revision and verify that the ABI field, ChangeLog revision, and version banner all match the Makefile pin.