{
  "added_at": "2026-11-09",
  "additional_evidence_urls": [
    "https://github.com/mist64/geos/blob/617efdc7191eda14eaf699d317e66d5bda68c039/regress.sh",
    "https://github.com/mist64/geos/tree/617efdc7191eda14eaf699d317e66d5bda68c039/reference"
  ],
  "category": "reconstruction-cases",
  "class": "software",
  "description_en": "Reorganized cc65 source for GEOS 2.0 on the Commodore 64 and 128. The README says a standard compile generates binaries identical to the GEOS 64 2.0 and GEOS 128 2.0 distribution binaries, and make regress compares the bsw and wheels builds with the reference tree.",
  "description_zh": "Commodore 64 与 128 上 GEOS 2.0 的整理后 cc65 源码。README 写明标准编译生成与 GEOS 64 2.0 和 GEOS 128 2.0 发行二进制相同的文件，并且 make regress 把 bsw 与 wheels 构建与参考树比较。",
  "entry_url": "https://awesomerea.org/resources/geos-20-kernal-case/",
  "entry_url_zh": "https://awesomerea.org/zh/resources/geos-20-kernal-case/",
  "evidence_url": "https://github.com/mist64/geos/blob/617efdc7191eda14eaf699d317e66d5bda68c039/README.md",
  "group": "cases",
  "id": "geos-20-kernal-case",
  "json_url": "https://awesomerea.org/resources/geos-20-kernal-case/record.json",
  "kind": "case-study",
  "markdown_url": "https://awesomerea.org/resources/geos-20-kernal-case/index.md",
  "markdown_url_zh": "https://awesomerea.org/zh/resources/geos-20-kernal-case/index.md",
  "name": "GEOS 2.0: source that rebuilds the cbmfiles KERNAL binaries",
  "name_zh": "GEOS 2.0：可重建 cbmfiles KERNAL 二进制的源码",
  "record_type": "resource",
  "relationship": "independent-reconstruction",
  "requirement_facets": [
    "prerequisites",
    "scope",
    "testing",
    "license"
  ],
  "requirements": [
    "The README builds with make. reference/ holds the original binaries from the cbmfiles.com version. make regress builds the bsw and wheels variants and compares them with those references.",
    "The README says this tree does not use the original encrypted loader and that the kernel is plaintext, matching the cbmfiles.com version it describes. It says the serial number 0x58B5 is pre-filled to match that version.",
    "make regress is the comparison named in the README.",
    "The repository root has no LICENSE file. The README says the intellectual property added by the reverse-engineering and the subsequent improvements is in the public domain, asks to be credited, and says to respect the license of the underlying GEOS work."
  ],
  "requirements_zh": [
    "README 用 make 构建。reference/ 存放来自 cbmfiles.com 版本的原始二进制。make regress 构建 bsw 和 wheels 变体并与这些参考比较。",
    "README 写明此树不使用原始加密加载器，内核为明文，与它描述的 cbmfiles.com 版本一致。它写明序列号 0x58B5 已预填以匹配该版本。",
    "README 点名的比较是 make regress。",
    "审阅的根目录没有 LICENSE 文件。README 写明逆向工程及随后改进所增加的知识产权属于公有领域，请求署名，并写明应尊重底层 GEOS 作品的许可证。"
  ],
  "targets": [
    "binary"
  ],
  "url": "https://github.com/mist64/geos",
  "verification": "source-reviewed",
  "verified_at": "2026-11-04"
}