Mac SE FDHD asks for floppy disk to boot

The Macintosh SE FDHD should work with any system between 6.0.3 and 7.5.5 (see https://support.apple.com/en-us/112181).

You mentioned creating a floppy on an old Mac. Was that the PowerBook 150? Any other Macintosh models available?

The Network Access Disk 7.5 is just one possible startup floppy. Apple's Disk Copy 4.2 can be used for making a properly sector-copied floppy from a disk image.

(download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Network_Access_Disk_7.5.txt)

(download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Disk_Copy/Disk_Copy_4.2.txt)

Thank you for the information.

Are you possibly running Mac OS 8.6 or 9.x on the iMac G3? If so, would it be correct to assume that you have a working and appropriate version of StuffIt Expander on that computer? In that case you may want to check whether a properly sector-copied Network Access 1.4 MB floppy can be created in the (USB) floppy drive connected to the iMac. Look upon this as an experiment, since the Power Macintosh 7200 with a built-in floppy drive is not working.

You would need to locate Disk Copy 4.2 and Network Access 7.5 files to do that. Earlier, these were downloadable here:

download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Disk_Copy/Disk_Copy_4.2.sea.bin

download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Network_Access_Disk_7.5.sea.bin

If you download MacBinary (.bin) files on another computer for transfer to the iMac G3, make sure that nothing is decoded/decompressed until on this iMac. The .bin is for protection, so do not alter anything earlier. Once on the iMac G3, drag the .bin files onto the StuffIt Expander icon for decoding. After decoding and decompression, a Network Access image file should be the result. Via the Disk Copy 4.2 utility, it is then possible to create a floppy from that image file.

FranOS9 (author)

Perhaps the unit requires a newer type floppy and also systems

files for that specific unit. Since I've repaired donated traded: 500+

older Apple and earlier Mac systems, with vintage SW versions.

There used to be many sources; now I see most that were common

condensed to other sources. OWC and Fixit are two among several

with ideas. To make this simple for me, & I've offline chores to do..

Note the FDHD was an upgrade to use higher capacity floppies

while the official disk was made for that model; a disk utility on

a floppy also exists..

.Here's a search result from browser DDG with most details too.

https://duckduckgo.com/?t=ftsa&q=Mac+SE+FDHD+boot+system+version+on+floppy&ia=web

Macintosh SE - Wikipedia

Macintosh SE FDHD OS | Vintage Computer Federation Forums

SOLVED: Startup problem with floppy? blinking - Macintosh SE FDHD

How to make Macintosh SE FDHD boot from external floppy ... - Reddit

-- I'm out of time, have an appointment; and Wx chances of freezing

rain/ice fog; plus snow is also working its way, again to sea-level here.

FranOS9 (author)

This link works when 'dragged & dropped' into an empty browser window & then a download..

download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Disk_Copy/Disk_Copy_4.2.sea.bin

..goes into your (computer or device) 'downloads' folder. This works here with three web

browsers in Mac mini 2012. Firefox ESR; Brave (& vintage Safari v 13.1.2 macOS10.13.6)

[So the other link should also. I'd use this as tool, to get the best one first.]

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