Post #2361111
2026-03-11 16:23 UTC
@3rz@freiburg.social 2S/4D 😲
I've never seen such a thing before!
Replies (1)
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@3rz@freiburg.social 2026-03-11 18:07
@sverx@mastodon.gamedev.place I assume some logic behind the “4D”, and that this media set is rather old (unfortunately no date on it). In the early 80ies, there were … • 40-track-3.5“ drives • Single-sided Like the Epson SMD-110, with 67.5 tpi. That’s either 82 KB (FM) on a 3.5“ disk, or 164 KB (MFM). If you now double both the tracks (40 to 80), and go from FM to MFM (doubling again), you end up from 1D to 4D. Or, what we nowadays call a “normal” 3.5“ DS/DD disk drive, with ~720 KBytes. In the attached image, the SMD-110 is to the very right. A “normal” 3.5“ DD drive is to the left, an Epson SMD-140. (And yes, the SMD-110 is not vaporware, we have a working one in the club)