Anatomy of the 1541 Disk Drive — Lothar Englisch & Norbert Szczepanowski (Abacus Software, 1984)
Program Protection Manual for the C-64 — T.N. Simstad / CSM Software, 1984
Scott Cronce / Disclone — Interview by John Aycock, University of Calgary, TR 2020-1117-03, July 2020 (CC BY-SA 3.0)
Pete Rittwage / C64 Preservation Project & Luigi Di Fraia / Antitrack / Fungus
Markus Brenner — VCF East 3 presentation: "Copy Protection vs. Emulators" (2003)
comp.sys.cbm Usenet archive — October–November 1999 thread "Info on copy protection?"
Harald Seeley — V-MAX! creator, direct posts on comp.sys.cbm, November 1999
Francis Yarra — RapidLok & V-MAX! analysis, comp.sys.cbm
CMD/Abacus software duplication accounts, comp.sys.cbm
Joseph Fenn (Kilroy) — DSI Pocket Writer analysis, comp.sys.cbm
OpenCBM/NIBTools GitHub documentation & copy protection handling guide
Pete Rittwage, Antitrack, Fungus — "Copy protection on the C64", Recollection #2, C64 Preservation Project
Snacky (Sigi) / Genesis*Project — Interview by Jazzcat, Recollection #1, 2006 (TIMEX cracking account, Rubicon protection design)
Ivo Herzeg (Mr. Cursor) / X-Ample Architectures — TIMEX creator
C64-Wiki — Ivo Herzeg biography
Lemon64 forum thread: "List of titles with Timex?" (community title enumeration)
Lenslok: John Frost / ASAP Developments — Wikipedia; Elite Archivists / Elite Wiki; Simon Owen: LensKey emulator; Lemon64 thread t=53706
Code Wheels: oldgames.sk/codewheel/ (interactive archive); LucasArts / TV Tropes; Tropedia; PC Gamer
Novaload / Tape Stack Hijack: MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022); Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution); Wikipedia: Commodore 64 peripherals; Lemon64 forum tape loaders thread Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Dalhousie Law Journal — Schulich School of Law, Dalhousie University (legal scholarship on software copy protection and Canadian copyright doctrine)
preservation64.de — Descriptions of old disk copy protections (Software Archive wiki; named protection catalogue documenting CYAN Loader, Ocean, Rainbow Arts V1/V2/V3, GMA series, Kingsoft, Melbourne House, Microprose, STP, Teque, Timer Disk, Burstnibbler, Cosmetic Disk Id, syncr0l0k, XELOCK V1.0, XROM System, and others)
Jim Drew — c64copyprotection.com (copy protection technique descriptions; first-person accounts of Fat Tracks / erase head guard band, Half-Track writing, Weak Bit / Clock Bits 1541 float behaviour, Duplicate Sector IDs, Sync Bytes / data separator difficulty, Drive error codes, Gaps and hardware copiers, Non-Standard format evolution)
Vittorio Paola & Gaetano Romano — Tecniche avanzate di protezione e sprotezione software, Libreria Dario Flaccovio Editrice, Palermo, 1986
Glenn Holmer ("ShadowM") — A Technical Overview of Commodore Copy Protection, World of Commodore Expo, 12/01/2007. www.lyonlabs.org/commodore/c64.html (GCR encoding details, protection type taxonomy, disk controller hardware registers, Abacus Assembler and Zorkquest disassemblies)
Michael Quigley — DiskBusters!, The Transactor, Volume 6 Issue 01, July 1985 (contemporary reviews of Di-Sector, Master Copy, Clone Machine / SuperClone, CSM Program Protection Manual, and Software Protection Handbook)

Anatomy of the 1541 Disk Drive — Lothar Englisch & Norbert Szczepanowski (Abacus Software, 1984)
Program Protection Manual for the C-64 — T.N. Simstad / CSM Software, 1984
Scott Cronce / Disclone — Interview by John Aycock, University of Calgary, TR 2020-1117-03, July 2020 (CC BY-SA 3.0)
Pete Rittwage / C64 Preservation Project & Luigi Di Fraia / Antitrack / Fungus
Pete Rittwage, Antitrack, Fungus — "Copy protection on the C64", Recollection #2, C64 Preservation Project (with inline commentary by Antitrack and Fungus). Source for: CYAN name origin, RADWAR/cracking group connection, Ocean bad sectors into 90s, gap byte gap-length explanation, Take Down Wrestling dual-CPU decryption, Star Rank Boxing p-code, Paperback Writer 100+ decode loops, Rubicon SKY signature, 3-track angular timer ratio, mid-track density switching, PirateBusters timer mechanism, Cartridge protection / TOKI.
Mike J. Henry / Lawrence Hiler / Basement Boys Software — In Search Of... Mike J. Henry, commodoregames.net (Di-Sector origins, Fast Hack'em history, Kracker Jax / Les Lawrence, Portland copy scene geography, RAMBOard, Maverick authorship)
Markus Brenner — VCF East 3 presentation: "Copy Protection vs. Emulators" (2003)
comp.sys.cbm Usenet archive — October–November 1999 thread "Info on copy protection?"
Harald Seeley — V-MAX! creator, direct posts on comp.sys.cbm, November 1999
Francis Yarra — RapidLok & V-MAX! analysis, comp.sys.cbm
CMD/Abacus software duplication accounts, comp.sys.cbm
Joseph Fenn (Kilroy) — DSI Pocket Writer analysis, comp.sys.cbm
OpenCBM/NIBTools GitHub documentation & copy protection handling guide
Ivo Herzeg (Mr. Cursor) / X-Ample Architectures — TIMEX creator
C64-Wiki — Ivo Herzeg biography
Lemon64 forum thread: "List of titles with Timex?" (community title enumeration)
Lenslok: John Frost / ASAP Developments — Wikipedia; Elite Archivists / Elite Wiki; Simon Owen: LensKey emulator; Lemon64 thread t=53706
Code Wheels: oldgames.sk/codewheel/ (interactive archive); LucasArts / TV Tropes; Tropedia; PC Gamer
Novaload / Tape Stack Hijack: MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022); Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution); Wikipedia: Commodore 64 peripherals; Lemon64 forum tape loaders thread Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Dalhousie Law Journal — Schulich School of Law, Dalhousie University (legal scholarship on software copy protection and Canadian copyright doctrine)
preservation64.de — Descriptions of old disk copy protections (Software Archive wiki; named protection catalogue documenting CYAN Loader, Ocean, Rainbow Arts V1/V2/V3, GMA series, Kingsoft, Melbourne House, Microprose, STP, Teque, Timer Disk, Burstnibbler, Cosmetic Disk Id, syncr0l0k, XELOCK V1.0, XROM System, and others)
Jim Drew — c64copyprotection.com (copy protection technique descriptions; first-person accounts of Fat Tracks / erase head guard band, Half-Track writing, Weak Bit / Clock Bits 1541 float behaviour, Duplicate Sector IDs, Sync Bytes / data separator difficulty, Drive error codes, Gaps and hardware copiers, Non-Standard format evolution)

MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022)
Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution)
Paul Hughes — Interview, The Mercenary Site, April 2020 (Freeload, NovaBill, Ocean loader history)
C64-Wiki — Novaload (bit timing, routine structure, tape buffer addresses, badline tolerance)
Wikipedia — Commodore 64 peripherals; Datasette
Lemon64 forum — tape loaders thread
Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Pete Rittwage / C64 Preservation Project — TAP format documentation
TAP format specification — VICE emulator documentation

Anatomy of the 1541 Disk Drive — Lothar Englisch & Norbert Szczepanowski (Abacus Software, 1984)
Program Protection Manual for the C-64 — T.N. Simstad / CSM Software, 1984
Scott Cronce / Disclone — Interview by John Aycock, University of Calgary, TR 2020-1117-03, July 2020 (CC BY-SA 3.0)
Pete Rittwage / C64 Preservation Project & Luigi Di Fraia / Antitrack / Fungus
Markus Brenner — VCF East 3 presentation: "Copy Protection vs. Emulators" (2003)
comp.sys.cbm Usenet archive — October–November 1999 thread "Info on copy protection?"
Harald Seeley — V-MAX! creator, direct posts on comp.sys.cbm, November 1999
Francis Yarra — RapidLok & V-MAX! analysis, comp.sys.cbm
CMD/Abacus software duplication accounts, comp.sys.cbm
Joseph Fenn (Kilroy) — DSI Pocket Writer analysis, comp.sys.cbm
OpenCBM/NIBTools GitHub documentation & copy protection handling guide
Pete Rittwage, Antitrack, Fungus — "Copy protection on the C64", Recollection #2, C64 Preservation Project
Ivo Herzeg (Mr. Cursor) / X-Ample Architectures — TIMEX creator
C64-Wiki — Ivo Herzeg biography
Lemon64 forum thread: "List of titles with Timex?" (community title enumeration)
Lenslok: John Frost / ASAP Developments — Wikipedia; Elite Archivists / Elite Wiki; Simon Owen: LensKey emulator; Lemon64 thread t=53706
Code Wheels: oldgames.sk/codewheel/ (interactive archive); LucasArts / TV Tropes; Tropedia; PC Gamer
Novaload / Tape Stack Hijack: MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022); Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution); Wikipedia: Commodore 64 peripherals; Lemon64 forum tape loaders thread Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Dalhousie Law Journal — Schulich School of Law, Dalhousie University (legal scholarship on software copy protection and Canadian copyright doctrine)
preservation64.de — Descriptions of old disk copy protections (Software Archive wiki; named protection catalogue documenting CYAN Loader, Ocean, Rainbow Arts V1/V2/V3, GMA series, Kingsoft, Melbourne House, Microprose, STP, Teque, Timer Disk, Burstnibbler, Cosmetic Disk Id, syncr0l0k, XELOCK V1.0, XROM System, and others)
Jim Drew — c64copyprotection.com (copy protection technique descriptions; first-person accounts of Fat Tracks / erase head guard band, Half-Track writing, Weak Bit / Clock Bits 1541 float behaviour, Duplicate Sector IDs, Sync Bytes / data separator difficulty, Drive error codes, Gaps and hardware copiers, Non-Standard format evolution)

Anatomy of the 1541 Disk Drive — Lothar Englisch & Norbert Szczepanowski (Abacus Software, 1984)
Program Protection Manual for the C-64 — T.N. Simstad / CSM Software, 1984
Scott Cronce / Disclone — Interview by John Aycock, University of Calgary, TR 2020-1117-03, July 2020 (CC BY-SA 3.0)
Pete Rittwage / C64 Preservation Project & Luigi Di Fraia / Antitrack / Fungus
Markus Brenner — VCF East 3 presentation: "Copy Protection vs. Emulators" (2003)
comp.sys.cbm Usenet archive — October–November 1999 thread "Info on copy protection?"
Harald Seeley — V-MAX! creator, direct posts on comp.sys.cbm, November 1999
Francis Yarra — RapidLok & V-MAX! analysis, comp.sys.cbm
CMD/Abacus software duplication accounts, comp.sys.cbm
Joseph Fenn (Kilroy) — DSI Pocket Writer analysis, comp.sys.cbm
OpenCBM/NIBTools GitHub documentation & copy protection handling guide
Pete Rittwage, Antitrack, Fungus — "Copy protection on the C64", Recollection #2, C64 Preservation Project (NIB format origins, 1541-II data separator difference, weak-bit capture warning, flux-level imaging context)
Mike J. Henry / Lawrence Hiler — In Search Of… Mike J. Henry, commodoregames.net (RAMBOard / parallel cable ecosystem history)
Ivo Herzeg (Mr. Cursor) / X-Ample Architectures — TIMEX creator
C64-Wiki — Ivo Herzeg biography
Lemon64 forum thread: "List of titles with Timex?" (community title enumeration)
Lenslok: John Frost / ASAP Developments — Wikipedia; Elite Archivists / Elite Wiki; Simon Owen: LensKey emulator; Lemon64 thread t=53706
Code Wheels: oldgames.sk/codewheel/ (interactive archive); LucasArts / TV Tropes; Tropedia; PC Gamer
Novaload / Tape Stack Hijack: MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022); Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution); Wikipedia: Commodore 64 peripherals; Lemon64 forum tape loaders thread Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Dalhousie Law Journal — Schulich School of Law, Dalhousie University (legal scholarship on software copy protection and Canadian copyright doctrine)
preservation64.de — Descriptions of old disk copy protections (Software Archive wiki; named protection catalogue documenting CYAN Loader, Ocean, Rainbow Arts V1/V2/V3, GMA series, Kingsoft, Melbourne House, Microprose, STP, Teque, Timer Disk, Burstnibbler, Cosmetic Disk Id, syncr0l0k, XELOCK V1.0, XROM System, and others)
Jim Drew — c64copyprotection.com (copy protection technique descriptions; first-person accounts of Fat Tracks / erase head guard band, Half-Track writing, Weak Bit / Clock Bits 1541 float behaviour, Duplicate Sector IDs, Sync Bytes / data separator difficulty, Drive error codes, Gaps and hardware copiers, Non-Standard format evolution)

Anatomy of the 1541 Disk Drive — Lothar Englisch & Norbert Szczepanowski (Abacus Software, 1984)
Program Protection Manual for the C-64 — T.N. Simstad / CSM Software, 1984
Scott Cronce / Disclone — Interview by John Aycock, University of Calgary, TR 2020-1117-03, July 2020 (CC BY-SA 3.0)
Pete Rittwage / C64 Preservation Project & Luigi Di Fraia / Antitrack / Fungus
Markus Brenner — VCF East 3 presentation: "Copy Protection vs. Emulators" (2003)
comp.sys.cbm Usenet archive — October–November 1999 thread "Info on copy protection?"
Harald Seeley — V-MAX! creator, direct posts on comp.sys.cbm, November 1999
Francis Yarra — RapidLok & V-MAX! analysis, comp.sys.cbm
CMD/Abacus software duplication accounts, comp.sys.cbm
Joseph Fenn (Kilroy) — DSI Pocket Writer analysis, comp.sys.cbm
OpenCBM/NIBTools GitHub documentation & copy protection handling guide
Ivo Herzeg (Mr. Cursor) / X-Ample Architectures — TIMEX creator
C64-Wiki — Ivo Herzeg biography
Lemon64 forum thread: "List of titles with Timex?" (community title enumeration)
Lenslok: John Frost / ASAP Developments — Wikipedia; Elite Archivists / Elite Wiki; Simon Owen: LensKey emulator; Lemon64 thread t=53706
Code Wheels: oldgames.sk/codewheel/ (interactive archive); LucasArts / TV Tropes; Tropedia; PC Gamer
Novaload / Tape Stack Hijack: MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022); Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution); Wikipedia: Commodore 64 peripherals; Lemon64 forum tape loaders thread Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Dalhousie Law Journal — Schulich School of Law, Dalhousie University (legal scholarship on software copy protection and Canadian copyright doctrine)
preservation64.de — Descriptions of old disk copy protections (Software Archive wiki; named protection catalogue documenting CYAN Loader, Ocean, Rainbow Arts V1/V2/V3, GMA series, Kingsoft, Melbourne House, Microprose, STP, Teque, Timer Disk, Burstnibbler, Cosmetic Disk Id, syncr0l0k, XELOCK V1.0, XROM System, and others)
Jim Drew — c64copyprotection.com (copy protection technique descriptions; first-person accounts of Fat Tracks / erase head guard band, Half-Track writing, Weak Bit / Clock Bits 1541 float behaviour, Duplicate Sector IDs, Sync Bytes / data separator difficulty, Drive error codes, Gaps and hardware copiers, Non-Standard format evolution)

Anatomy of the 1541 Disk Drive — Lothar Englisch & Norbert Szczepanowski (Abacus Software, 1984)
Program Protection Manual for the C-64 — T.N. Simstad / CSM Software, 1984
Scott Cronce / Disclone — Interview by John Aycock, University of Calgary, TR 2020-1117-03, July 2020 (CC BY-SA 3.0)
Pete Rittwage / C64 Preservation Project & Luigi Di Fraia / Antitrack / Fungus
Markus Brenner — VCF East 3 presentation: "Copy Protection vs. Emulators" (2003)
comp.sys.cbm Usenet archive — October–November 1999 thread "Info on copy protection?"
Harald Seeley — V-MAX! creator, direct posts on comp.sys.cbm, November 1999
Francis Yarra — RapidLok & V-MAX! analysis, comp.sys.cbm
CMD/Abacus software duplication accounts, comp.sys.cbm
Joseph Fenn (Kilroy) — DSI Pocket Writer analysis, comp.sys.cbm
OpenCBM/NIBTools GitHub documentation & copy protection handling guide
Pete Rittwage, Antitrack, Fungus — "Copy protection on the C64," C64 Preservation Project (Jim Butterfield DISK COPY/ALL origin, Turbo Nibbler gap handling, ZipCode format context)
Mike J. Henry / Lawrence Hiler — In Search Of… Mike J. Henry, commodoregames.net (Di-Sector history, Fast Hack'em version history and autonomous mode, Maverick authorship, Kracker Jax / Jim Drew / Les Lawrence origin story, Super Parameters / Kracker Pak name conflict, ISEPIC / Chip Gracey, Portland-area scene geography, RAMBOard / Chip Level Designs, Action Replay / Datel dual role)
Ivo Herzeg (Mr. Cursor) / X-Ample Architectures — TIMEX creator
C64-Wiki — Ivo Herzeg biography
Lemon64 forum thread: "List of titles with Timex?" (community title enumeration)
Lenslok: John Frost / ASAP Developments — Wikipedia; Elite Archivists / Elite Wiki; Simon Owen: LensKey emulator; Lemon64 thread t=53706
Code Wheels: oldgames.sk/codewheel/ (interactive archive); LucasArts / TV Tropes; Tropedia; PC Gamer
Novaload / Tape Stack Hijack: MuckyPaws — "NOVALOAD – Commodore Speed Load and Protection System Hacked" (2022); Spillhistorie.no — "The masters of Commodore 64 games" (Gary J. Sabin / US Gold Novaload music attribution); Wikipedia: Commodore 64 peripherals; Lemon64 forum tape loaders thread Jimmy Maher — "A Pirate's Life for Me, Part 3: Case Studies in Copy Protection", The Digital Antiquarian, January 2016
Dalhousie Law Journal — Schulich School of Law, Dalhousie University (legal scholarship on software copy protection and Canadian copyright doctrine)
preservation64.de — Descriptions of old disk copy protections (Software Archive wiki; named protection catalogue documenting CYAN Loader, Ocean, Rainbow Arts V1/V2/V3, GMA series, Kingsoft, Melbourne House, Microprose, STP, Teque, Timer Disk, Turbo Nibbler (EuroSystems), Cosmetic Disk Id, syncr0l0k, XELOCK V1.0, XROM System, and others)
Jim Drew — c64copyprotection.com (copy protection technique descriptions; first-person accounts of Fat Tracks / erase head guard band, Half-Track writing, Weak Bit / Clock Bits 1541 float behaviour, Duplicate Sector IDs, Sync Bytes / data separator difficulty, Drive error codes, Gaps and hardware copiers, Non-Standard format evolution)