Self booting 3.5 floppy

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Self booting 3.5 floppy

Postby Iudex » Thu Dec 13, 2012 6:42 pm

To make transfering files easier from a modern computer to the pcjr I put a 3.5 720kb floppy in the pcjr. I have a dos2.1 image file on the 720kb disk but the pcjr says it is not a bootable disk. It is formatted as FAT 12bit. Does any one have any suggestion of how to proceed?

Thank you
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Re: Self booting 3.5 floppy

Postby jmetal88 » Thu Dec 13, 2012 8:31 pm

The PCjr can only read 360k disks at boot. You can use a 3.5" floppy drive, but you have to format the boot disk as if it were a 360k disk. You can put a DRIVPARM line in your config.sys file to tell DOS it's really a 720k drive.
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Re: Self booting 3.5 floppy

Postby Iudex » Sat Dec 15, 2012 6:08 am

I was able to format the 720k disk to 360k. The pcjr did not give me any messages with format but it did not load the files either; it just gave me a blinking cursor. Am I missing something? Thank you.
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Re: Self booting 3.5 floppy

Postby Brutman » Sat Dec 15, 2012 8:03 am

Are you sure it is a real 720KB floppy, or is it a 1.44MB floppy?

I've had that problem with 1.44MB floppies. They will pass the diagnostics, but not boot. But on the real 720KB drives that I have tried it works fine.

You might be better off finding an old BackPack 3.5" floppy drive that connects to the parallel port. They work fine on the PCjr for data transfer.

Mike
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