Hyperformat

Hyperformat was born out of a clinical condition known as sector envy. When I got my first ST, religious wars waged between Atari and Amiga owners. (Might be amusing and/or embarassing to revisit those exchanges now...) Every little detail of the two systems was compared with fervor. Because floppy disks were the storage medium de rigeur at the time, (floppy) disk space was one of those details.

Amiga systems stored roughly 880 KB on one double-density floppy disk. Atari's TOS, however, stored only 720 KB by default. Very soon, clever Atari programmers found that it was possible to use 10 instead of 9 sectors per track, increasing the disk space to roughly 800 KB.

Not bad, I thought, but I wasn't satisifed; the extra 80 KB on the Amiga bothered me. And so I set out to learn the low-level details of how both the Amiga and the Atari stored their data on floppy disk.

I disassembled operating system code. I dug through system programming manuals. I tried to understand floppy disk controller principles, and the particulars of Western Digital's 1772 floppy disk controller which was used in the Atari. My head was spinning.

Hyperformat was the result. By tuning the track parameters to the maximum, it allowed the Atari to match the Amiga's capabilities - 880 KB on a standard DD floppy disk, and even more by using extra tracks. (Most floppy disk drives allowed to store data even beyond track 79, which was nominally the "last" track for DD disks.)

Hyperformat was indeed a real breakthrough. Other formatters came after it, but it was this little piece of code, written entirely in 68000 assembly language, which proved that it could be done. I published an article on it in ST-Computer magazine; the article turned into a a series on disk programming - and from the series, the idea of a book came up: Scheibenkleister.

So basically, it was the Amiga which led me into writing a book on Atari disk and system programming. Only one of the reasons why I still think that the Amiga was a fine system in many respects.

An extended version of Hyperformat was shipped with Scheibenkleister, and later Hyperformat broke even more records - for example, it was the first formatter which supported overclocked FDCs and high-density disks. If you wanted to squeeze the maximum out of your floppy disk, Hyperformat was your weapon.

• Hyp Hyp Hurra - Die Geschichte von Hyperformat
• Programming information for the WD1770/1772 (funet.fi)
• Original 1772 product spec by WD (scanned images)
• Probing the FDC (Dave Small)
• Hyperformat

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