# An Interview With Bil Herd - Zany Z80 Zygology

- Show: [The Amp Hour](https://hardwarepodcasts.com/podcast/the-amp-hour)
- Published: 2014-10-29
- Length: 2h 01m
- Episode: 222
- Page: https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology
- Listen: https://theamphour.com/222-an-interview-with-bil-herd-zany-z80-zygology/

## Summary

Bil Herd, a recovering Commodore engineer, recounts the chaotic development of the Commodore 128, explaining how they integrated a Z80 processor to ensure CPM compatibility and bypass TI interference. He details the extreme time pressures of the 1985 CES cycle, describing how the team used 'dirty design' tricks like phase-locked clocks and hand-wired jumpers to fix metastability and signal reflection issues in custom NMOS chips. Herd also discusses the company's flat, high-stress culture under Jack Tramiel, the transition from hand-taped layouts to early CAD, and the eventual cancellation of the Commodore LCD laptop project.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=0) Introduction: Bil Herd and the Commodore 128
- [1:03](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=63) The Z80 Controversy and Anti-Piracy Measures
- [4:23](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=263) Commodore's Flat Structure and Jack Tramiel's Dictatorship
- [8:12](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=492) Herd's Early Career: Troubleshooting and Army Service
- [19:57](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=1197) The C64's Timing Problems and Production Kludges
- [28:19](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=1699) Custom Chips: The VIC, 6502, and Sprite Technology
- [35:30](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=2130) Designing the C128: Single-Chip Origins and MMU
- [43:18](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=2598) Chip Fabrication: Probing, Schmoozing, and 1-2-3 Patches
- [53:57](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=3237) The Z80 Clock Hack and FCC Loopholes
- [1:03:02](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=3782) Fixing Bus Reflections with the Red Wire
- [1:12:25](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=4345) The 6502 History: Chuck Peddle, MOS, and Steve Jobs
- [1:19:44](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=4784) Why the C128 Needed a Dual-Processor System
- [1:28:57](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=5337) The Commodore LCD Laptop and Project Cancellation
- [1:44:34](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-10-29-an-interview-with-bil-herd-zany-z80-zygology#t=6274) Commodore's Decline: Jack Tramiel's Departure and Bankruptcy

## Topics

- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Chips, FPGAs & semiconductors](https://hardwarepodcasts.com/topic/chips-and-fpgas)
- [Microcontrollers & dev platforms](https://hardwarepodcasts.com/topic/microcontrollers-and-platforms)
- [Debugging & failure analysis](https://hardwarepodcasts.com/topic/debugging-and-failure-analysis)
- [Manufacturing partners & offshoring](https://hardwarepodcasts.com/topic/manufacturing-partners)
- [Starting a product company](https://hardwarepodcasts.com/topic/starting-a-company)

## Most relevant to

established companies

## Mentioned

- Commodore 128 (product)
- Z80 (chip)
- Commodore 64 (product)
- VIC chip (chip)
- 6502 (chip)
- MOS Technology (company)
- Jack Tramiel (other)
- Chuck Peddle (other)
- Steve Jobs (other)
- TI-99/4A (product)
- CPM (other)
- Commodore LCD (product)
- Radio Shack Model 100 (product)
- Hackaday (other)

## Related episodes from other shows

- [005 - Circuits That Go Nowhere](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2017-11-06-005-circuits-that-go-nowhere) (Unnamed Reverse Engineering Podcast)
- [052 - Twitter Is My Lab Notebook](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2021-10-26-052-twitter-is-my-lab-notebook) (Unnamed Reverse Engineering Podcast)
- [026 - You Can Lose in so Many Colors!](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2019-08-31-026-you-can-lose-in-so-many-colors) (Unnamed Reverse Engineering Podcast)
- [A Requiem for SPARC with Tom Lyon](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-05-11-a-requiem-for-sparc-with-tom-lyon) (Oxide and Friends)
- [376: Left Half of My Brain Is Digital](https://hardwarepodcasts.com/podcast/embedded-fm/2021-06-10-376-left-half-of-my-brain-is-digital) (Embedded.fm)

## Citing this page

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