Home / feilipu / 8085-skills · .agents/skills/cpu-8085/SKILL.md · GitHub

cpu-8085 skillA

cpu-8085 is agent-read markdown (skill) from feilipu/8085-skills: Intel 8085 assembly for z88dk: Zilog mnemonics, full opcode map (flags K/V, timings), and extended-instruction usage. Strong rule: stack-only locals and intermediates; do not invent BSS scratch (C static / file-scope stay BSS). Prefer when writing or reviewing 8085 library asm, mapping Intel↔Zilog, choosing stack frames, K-flag loops, restoring float/integer divide, legal (de) stores, jr-as-jp synthetics, or /cpu-8085..

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

What the file says

# CPU — 8085

Compatible extension of the Intel 8080 (April 1974). Same documented 8080 ops; ten extra ops in 8080 unused cells. **This skill is complete for opcodes, flags, timings, and extended-op usage.** C90 kernels and agent-emitted listings: **`compiler-ac85`**. 8080-only jobs (no extras) use `cpu-8080` in the z88dk tree — this pack does not ship it.

z88dk uses **Zilog mnemonics** for 8085 sources. Extended opcodes are first-class on every 8085. Design notes: https://feilipu.me/2021/09/27/8085-software/

## Conventions (always follow)

1. **Mnemonics are Zilog**, as in Z80 assembly — not Intel 8080/8085 names.
2. **Opcode bytes and timings are 8085**, not 8080 and not Z80.
3. **Undocumented / extended** opcodes are noted in tables (column or section).
4. Immediate forms: `*` = 8-bit immediate (d8), `**` = 16-bit immediate/address (d16/a16). These `*`/`**` are operand placeholders only.
5. For **LDHI** / **LDSI** equivalents (`ld de,hl+*` / `ld de,sp+*`), the 8-bit offset is **unsigned**.
6. Conditional cycle counts use `taken/not-taken` (e.g. `12/6`, `10/7`, `18/9`).
…

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How to install

Latest version
mdr add feilipu/8085-skills/cpu-8085@git:20260921.85b9514
Exact content
mdr add feilipu/8085-skills/cpu-8085@sha256:a9429b7d45397dc0

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

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Versions

versioncommittedcommitsizeaudit
git:20260921.85b9514 latest2026-09-21 85b9514 30,680 BA view · diff
git:20260921.2f39ee62026-09-21 2f39ee6 30,643 BA view · diff
git:20260920.88ac0a12026-09-20 88ac0a1 30,011 BA view · diff
git:20260920.d8931322026-09-20 d893132 29,760 BA view · diff
git:20260919.24cc48b2026-09-19 24cc48b 28,354 BA view · diff
git:20260919.216763a2026-09-19 216763a 26,756 BA view · diff
git:20260918.86bba032026-09-18 86bba03 26,753 BA view · diff
git:20260918.792b4a62026-09-18 792b4a6 26,352 BA view · diff
git:20260918.95c45882026-09-18 95c4588 26,293 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (30680 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

feilipu/8085-skills · 3 stars · license MIT · pushed 2026-09-21 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_4fpzpohngggznwkh
GET https://markdownregistry.com/api/v1/resolve?ref=feilipu/8085-skills/cpu-8085
GET https://markdownregistry.com/api/v1/blob/a9429b7d45397dc0506a41d4e0f95deb7cbdc0a9072bdbba0e51b4e20c2c320c

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