Mac OS 9 Lives

Mac OS 9 Discussion => Hardware => Storage => Topic started by: hjalfi on August 25, 2022, 08:34:39 AM

Title: Extension for 400kB MFS disk support?
Post by: hjalfi on August 25, 2022, 08:34:39 AM

I have a PowerBook 150. I want to be able to format and use 400kB MFS disks, which it doesn't support. (For testing creation of MFS disks with FluxEngine.)

My understanding is that 400kB disks are physically the same as 800kB disks, just single-sided and with a different filesystem, so adding support ought to be a simple software matter. Does such an extension already exist?

Title: Re: Extension for 400kB MFS disk support?
Post by: smilesdavis on November 11, 2024, 06:58:08 AM

you want https://applesaucefdc.com/ and nothing else

Title: Re: Extension for 400kB MFS disk support?
Post by: robespierre on November 11, 2024, 08:59:56 AM

Try using System 7.1 and selecting "Single Sided" from the Format... dialog.

Title: Re: Extension for 400kB MFS disk support?
Post by: Jubadub on April 09, 2025, 12:20:14 AM

Quote from: robespierre on November 11, 2024, 08:59:56 AM

Try using System 7.1 and selecting "Single Sided" from the Format... dialog.

*Like* :)

System 7.1.2P is the latest version of Mac OS that allows formatting MFS disks. System 7.5 ~ 7.6 can still write data to existing MFS disks, whereas 7.6.1 is able to only read data from them, and starting with Mac OS 8.0, such disks don't even get mounted at all.

Bringing back to Mac OS 9.2.2 what was lost from earlier system versions would definitely be something to try.

Of course, you should be able to use System 7.1.2P (and any other System before Mac OS 7.6) in Mini vMac from Mac OS 9, although I never tried to use Mini vMac to format real floppies or CDs, so I don't know for sure it is able to do that. But you definitely can create MFS disk images from it.