I've got a 5.25" floppy disk that used to just boot up in BASIC with a home made loader. At some point, it just stopped working. Side B works, though.
What is the best method that I can go about making a backup of this disk in its current state and then dissecting the data in hex... or something?
I am hoping to either recover what's left, figure out what got corrupted, or simply figure out the names of the programs that were on Side A.
Thanks for all your insights!!
One way would be to use ADTPro to upload a copy of your broken disk to your PC/Mac. You then have a backup. And you can load the disk image as a disk in an Apple II emulator - and use the emulator's debugger to step through the (broken) custom loader to see what's wrong.
... it just stopped working
Does it not boot at all or just not run the loader program? Either way, if you boot with another DOS disk and then CATALOG the corrupt side you might be able to see the names of the programs on that disk. If it just doesn't boot, you can use COPY II Plus to either copy DOS from another disk or just copy all of the files over to a new disk.
So, I have a CFFA card installed and when I type the CATALOG command, it lists the contents of the root of the CFFA card. How can I go about forcing the CATALOG command to catalog the contents of my 5.25" drive instead of the CFFA?
Thank you :)
Depends on how you have the drives connected. Is the DISK II connected to the CFFA or a separate controller in a different slot? If the CFFA is slot 7 and Disk II is in slot 6, try CATALOG,S6. Make sure the CFFA "virtual drive" is not set to the same slot.
I believe that is correct. I just booted it up and did a test CATALOG,S6 on a known working disk, and it worked perfectly!
I put in the offending disk, however, and the same CATALOG,S6 command gives me quick access sound followed by an "I/O ERROR" message. I flipped the disk and tried again, same error message.
Attempting to boot Side A gives me an error message: "Not a startup disk!"
Booting Side B loads the visual "start" screen for the game Karteka, but if any key is pressed, it clearly crashes and re-boots.
So, there is clearly something amiss with the disk itself. All other disks work fine in the drive.
On a PC, I know how to make disk images and analyze them, but I don't have any idea how to do that with Apple II disks. As a result, I feel at a big disadvantage. Is there any software or commands that can go sector-by-sector or otherwise slowly analyze the hex? Like, force it to start at 0x000001?
Thanks everyone for all your help and patience :)
Some disks just rot over time. Some may have gotten dirty and need to be cleaned. You can buy a 3D printed frame that hold disks and has a knob to spin the disk. Then you take some isopropyl alcohol (the higher the percentage the better) and a microfiber cloth to clean them. I've had luck reading disks after cleaning that wouldn't read before. Also, clean your head anytime you read an old disk that has not been cleaned. The surface of the disk is prone to growing mold if not stored in ideal conditions. And that will rub off on the head. In extreme cases, that mold can build up in the head and damage other disks you try to read.
Copy II Plus is a great utility for working with disks. It also has the ability to "check" files and complete disks for errors; but no tools to fix them. It can also let you view files but that is not all that useful. Bag of Tricks can analyze and repair disks.
Sounds like I should boot up Copy II Plus or Bag of Tricks from the CFFA and then try to check the disk from that.
I will give that a try :)
This is an important comment. Visually inspect the faulty disk. And cisually inspect the read-write head on the disk drive, and clean it with a cotton swab soaked in isopropyl alcohol, or my favourite cleaner, "Ronsonol" also known as "Zippo" lighter fluid.
If the cause of the issue is mould growth on the diskette media itself, then very likely you will see a faint continuous concentric scratch on the diskette itself at the outer perimiter.
If that is there, then track zero is toast and the diskette is pretty much useless you have something like an Applesauce Device, which is a flux-image reader that can probably find whatever else is there on the diskette that is readable.
The disk will be useless anyway because of the mould buildup on it. In those cases I slit the protective jacket, physically remove the magnetic media from the jacket, wash it carefully with warm water and dish soap, dry it carefully, and reinsert it in the jacket. Then I use ADTPro or AppleSauce to create a disk image of it and I then throw the disk into the trash.
I find that maybe 30% of old diskettes I come across have mould growth on them, especially if they were stored in damp conditions (like in someone's basement for 30 years).
If they are stored properly they rarely have any issues.
A much better approach is to use Saltine's Super Transcopy and get the raw NIBs. Instructions how to use are inside the ZIP in the DOC file. You can do 2 or 3 passes and compare the NIB files with WinMerge to see if they are always the same or end up being different each time, which would suggest a demagnetized floppy disk.