
Internet History Podcast 18. The True Story Behind Halt And Catch Fire - An Interview With Rod Canion
20 snips
May 26, 2014 AI Snips
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Compatibility Was The Killer Feature
- Rod Canion realized a portable PC would only succeed if it ran the existing IBM PC software ecosystem.
- He decided to reverse engineer IBM's BIOS and adapt MS-DOS so users could run VisiCalc and other apps without porting.
Clean Room Reverse Engineering Story
- Compaq used a two-person clean-room approach to legally recreate IBM's copyrighted BIOS.
- One engineer wrote a spec from IBM's behavior, then another who'd never seen IBM's code implemented fresh BIOS code to match functionality.
MS-DOS Variants Required Heavy Compatibility Work
- Microsoft’s MS-DOS variants were not fully compatible across vendors, forcing Compaq to extensively modify DOS to run third‑party software.
- Compaq spent months and hundreds of DOS changes to achieve near‑perfect compatibility.
