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Macintosh Floppy EMU SSD

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once he gets the HD20 emu(IWM Hard Drive) going with it… then you can boot up all these macs with it

 

128

512k

512ke

plus

se

portable

II (with simm socket soldered on)

IIx/

IIfx/

IIcx/

IIsi/

IIci/

SE30

Classic I

Classic II

 

but as far as just emulating floppy disk, i would like to say any mac with a floppy port is capable… i wonder if the 233 iMac de soldered floppy port could even use this floppy emu.

 

it also works with the IIgs

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I'm the developer - feel free to ask any questions you might have. There are a couple of threads about Floppy Emu already in the hacks forum.

 

Emulation works for 400K, 800K, or 1.4MB disk images with Macs from the original 128K to the Power Mac series. I haven't looked into the HD20 emulation yet that uniserver mentioned, but it should be theoretically possible since it uses the same interface.

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...I've had a question for a while now concerning the HD20.

 

Is it capable to have a higher drive capacity? I know it isn't really possible to replace the 20MB HDD in a real unit, but is there anything in the HD20 protocol to limit you to 20MB? (or 32MB? or 2GB?..) :-D

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Is it capable to have a higher drive capacity? I know it isn't really possible to replace the 20MB HDD in a real unit, but is there anything in the HD20 protocol to limit you to 20MB? (or 32MB? or 2GB?..) :-D

 

I'm too lazy to find the link to back this up (it's in one of the old threads about the HD-20), but the communication protocol for the HD-20 includes a method for the drive to communicate its size to the host. The HD-20 protocol was designed to allow any sort of "drive-like storage device" to be attached; the hard drive icon that appears on the screen when an HD-20 is running is actually stored in the HD-20's ROM, and it uses linear block addressing, IE, sectors are numbered from zero to (the number of sectors on the drive) similarly to SCSI.

 

So, yes, in theory if someone were to make an HD-20 emulator it should be able to accommodate disks larger than 20MB without having to change the ROM code/HD-20 init. (Within reason, of course. There's undoubtedly some hard limit on the number of sectors the drive ID data structure can communicate, probably somewhere south of 2GB.)

Edited by Gorgonops

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the hard drive icon that appears on the screen when an HD-20 is running is actually stored in the HD-20's ROM

How has this been verified? Is there a dissected HD-20 ROM dump somewhere? Or is it referenced in some Apple literature?

 

I ask because the original HD-20 startup disk (System 2.1/Finder 5.0) does contain the HD-20 icon in the System Folder SICN file. However, it's not in System 3.0 which has no SICN file at all. I feel like someone mentioned that the HD-20 ROM is coded like the 128/512K ROMs, making looking around it with Res-edit impossible. In which case, could the icon also be in the patched code file that the HD-20 INIT loads, or in lieu of residing on the HD-20 ROM itself?

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Hi again,

 

Does anyone know if it has support for folders? Could I label different folders ( games, apps, ect) and select them From the EMU or does it only support images located in the root directory of the SD card.

 

I remember this being one of the early problems with the CFFA card before they got a firmware update to resolve the single directory limitation.

 

Thanks

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the hard drive icon that appears on the screen when an HD-20 is running is actually stored in the HD-20's ROM

How has this been verified? Is there a dissected HD-20 ROM dump somewhere? Or is it referenced in some Apple literature?

 

I can tell you I've been disassembling the HD-20 driver in the Plus ROM and there are 256 bytes dedicated in the HD-20's status reply message for storing an icon. There is also a status bit that tells the Mac whether the HD-20 actually has an icon in that location. The HD-20 driver, when asked for an icon by the operating system (or whoever else), will happily return the icon sent from the HD-20 if it exists, or otherwise an error code.

 

Does anyone know if it has support for folders? Could I label different folders ( games, apps, ect) and select them From the EMU or does it only support images located in the root directory of the SD card.

 

Yep, bigmessowires added support for folders in one of the later updates. Works great!

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