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Ah good times, I remember spending countless hours typing in source code like this. At one point I also submitted the source for a couple of games I'd written t

Ah good times, I remember spending countless hours typing in source code like this. At one point I also submitted the source for a couple of games I'd written to a computer magazine when I was younger, and was delighted to get one of them published. My address was included; if people sent me a $5 note and a 5.25" floppy I'd return their disk containing a copy of the game plus a couple of other "bonus" apps I'd written. I think I sold maybe 4-5 copies this way and was pretty pleased with myself at the time! I do recall having to send a disk back and forth a few times to one customer because I'd reformatted his disk to double-sided (360k) but he only had a single-sided drive[0]. After he tried and failed to read it, I spoke to him on the phone, figured out the problem and asked him to return it. I reformatted the disk back to single-sided (180k) so he could try again. That didn't work either since it turned out the single sided drive only supported 160k rather than 180k, which necessitated yet another round trip of his disk through the postal system. [0] I'd been using a Sanyo MBC-555-2, he had a Sanyo MBC-550.

benj111 8y ago
Do you mean double sided or double density? I distinctly recall having to rotate discs on my BBC, and seems strange to needlessly break backwards compatibility.
- chris_overseas 8y ago
  His drive was single-sided double-density, giving 160k storage. The ones I was using were double-sided double-density, providing 360k of storage. I have no idea why the single sided drive had a bit less than half the storage of the double sided one though. There were two "hacks" available with single vs double sided drives and disks. 5.25" floppies had a small notch in the side that, if you covered it with a sticker, meant the drive treated it as read-only. By cutting an equivalent notch in the opposite side of a disk to make it appear writable it was possible to flip it over 180° and use both sides of a double-sided disk in a single-sided drive. Conversely, disks that were rated as single-sided (and hence cheaper) could generally still be used successfully in a double-sided drive, though it wasn't recommended to store anything too important that way because the failure/problem rate was noticeably higher. My guess is that the single sided disks were binned as such due to them failing tests on one of the sides during manufacturing.
  - benj111 8y ago
    Ah I see, so he had sent you a single sided disc then, that makes sense.

benj111 8y ago

Do you mean double sided or double density? I distinctly recall having to rotate discs on my BBC, and seems strange to needlessly break backwards compatibility.

chris_overseas 8y ago
His drive was single-sided double-density, giving 160k storage. The ones I was using were double-sided double-density, providing 360k of storage. I have no idea why the single sided drive had a bit less than half the storage of the double sided one though. There were two "hacks" available with single vs double sided drives and disks. 5.25" floppies had a small notch in the side that, if you covered it with a sticker, meant the drive treated it as read-only. By cutting an equivalent notch in the opposite side of a disk to make it appear writable it was possible to flip it over 180° and use both sides of a double-sided disk in a single-sided drive. Conversely, disks that were rated as single-sided (and hence cheaper) could generally still be used successfully in a double-sided drive, though it wasn't recommended to store anything too important that way because the failure/problem rate was noticeably higher. My guess is that the single sided disks were binned as such due to them failing tests on one of the sides during manufacturing.
- benj111 8y ago
  Ah I see, so he had sent you a single sided disc then, that makes sense.