Read/Backup problems when using SD HxC FDE

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Jman
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Joined: Mon Feb 15, 2010 6:19 am

Read/Backup problems when using SD HxC FDE

Post by Jman »

I have been trying to copy a floppy disc image and have finally succeeded by using the machines disk backup utility to copy from real stiffy drive A to blank image (I think goemetry is good) on HxC SD FDE drive B.

The image and HxC work good most of the time. I have 2 problems:

1) FDC will experience random read errors, not too often though. Sometimes so bad that the machine can not boot up.

2) Floppy image obtained from using machine to backup from real floppy to emulated floppy works, but if I copy the image to the PC then back to SD the new copy will have same symptoms like in 1) but worse (usually image is then not usable). This makes a problem for backing up the image to HDD.

I find these problems very strange because SD HxC FDE is obviously more accurate and reliable than floppy. Also image is copied from FAT32 to NTFS then back to FAT32 so even if SD/FAT32 storage sectors change the data is still read and handled the same by PIC?

I can not decide if this is compatibility, geometry, FDC, or machine problem.

Thanks for any advice!


Note: Problem 1) is also experienced with 3.5" floppy after 4 months.
I have tried backup of the image from 2 different PCs.
FDC is Intel 8272.

Edit: hmm looks like the SD card is the fault... I hope! I can not even format it now.

Jman
Posts: 16
Joined: Mon Feb 15, 2010 6:19 am

Post by Jman »

Nope the SD Card is good and I even replaced the SD Card Holder for fear of cracked pins. I still can not make backups of the floppy images without corrupting the card

Jeff
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Post by Jeff »

Jman wrote:Nope the SD Card is good and I even replaced the SD Card Holder for fear of cracked pins. I still can not make backups of the floppy images without corrupting the card

What do you mean exactly by "make backups of the floppy images" ?

Jman
Posts: 16
Joined: Mon Feb 15, 2010 6:19 am

Post by Jman »

Jeff wrote:
Jman wrote:Nope the SD Card is good and I even replaced the SD Card Holder for fear of cracked pins. I still can not make backups of the floppy images without corrupting the card

What do you mean exactly by "make backups of the floppy images" ?
I mean to copy the hfe file from SD card onto the computer (simple copy and paste with windows explorer from SD card onto Drive C) and vice-versa.

My problem is that after copying I can not use the image anymore (it worked good before copying).

Jeff
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Post by Jeff »

Jman wrote:
Jeff wrote:
Jman wrote:Nope the SD Card is good and I even replaced the SD Card Holder for fear of cracked pins. I still can not make backups of the floppy images without corrupting the card

What do you mean exactly by "make backups of the floppy images" ?
I mean to copy the hfe file from SD card onto the computer (simple copy and paste with windows explorer from SD card onto Drive C) and vice-versa.

My problem is that after copying I can not use the image anymore (it worked good before copying).

mhhh this is very strange. when exactly did you get the file corrupted ?

Jman
Posts: 16
Joined: Mon Feb 15, 2010 6:19 am

Post by Jman »

Jeff wrote:
Jman wrote:
Jeff wrote:
What do you mean exactly by "make backups of the floppy images" ?
I mean to copy the hfe file from SD card onto the computer (simple copy and paste with windows explorer from SD card onto Drive C) and vice-versa.

My problem is that after copying I can not use the image anymore (it worked good before copying).

mhhh this is very strange. when exactly did you get the file corrupted ?
This is difficult to say but it seems it is either when I copy from PC onto SD card or when I 1st try to read the SD Card on the AA machine after copying. More likely it is when the machine 1st tries to read the SD card as the HxC FDE functions perfect when I use it purely on a PC.

I have not had chance yet but I am going to do MD5 checks at different stages to see if I can detect when exactly the file is corrupted. There is a chance that the file is not even corrupt but for some reason it won't read on the machine after copying (perhaps related to file system?).

What I can say for sure is that once the SD card becomes "corrupt" it will not even work properly on a PC until it is re-formatted.

Edit: Symptoms of not working properly on PC are:
- very slow access time to SD Card
- sometimes SD is not accessible (I get "disk in drive X: is not formatted. Do you want to format now?")

Jeff
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Post by Jeff »

Jman wrote:
Jeff wrote:
Jman wrote: I mean to copy the hfe file from SD card onto the computer (simple copy and paste with windows explorer from SD card onto Drive C) and vice-versa.

My problem is that after copying I can not use the image anymore (it worked good before copying).

mhhh this is very strange. when exactly did you get the file corrupted ?
This is difficult to say but it seems it is either when I copy from PC onto SD card or when I 1st try to read the SD Card on the AA machine after copying. More likely it is when the machine 1st tries to read the SD card as the HxC FDE functions perfect when I use it purely on a PC.

I have not had chance yet but I am going to do MD5 checks at different stages to see if I can detect when exactly the file is corrupted. There is a chance that the file is not even corrupt but for some reason it won't read on the machine after copying (perhaps related to file system?).

What I can say for sure is that once the SD card becomes "corrupt" it will not even work properly on a PC until it is re-formatted.

Edit: Symptoms of not working properly on PC are:
- very slow access time to SD Card
- sometimes SD is not accessible (I get "disk in drive X: is not formatted. Do you want to format now?")
did you check the 3.3V regulator circuit of the hxcfe ?

Jman
Posts: 16
Joined: Mon Feb 15, 2010 6:19 am

Post by Jman »

My multimeter reads 3.3V. I haven't checked for ripple with an oscilloscope yet.
Edit: Oh yeah it just hit me, I probably won't have ripple problem with a regulator.

Also I have done much testing for continuity and short-circuits on the PCB. Some of the tracks came out very thin, but I thought this is not a problem because HxC FDE works excellent on a PC.

Jeff
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Post by Jeff »

Jman wrote:My multimeter reads 3.3V. I haven't checked for ripple with an oscilloscope yet.
Edit: Oh yeah it just hit me, I probably won't have ripple problem with a regulator.

Also I have done much testing for continuity and short-circuits on the PCB. Some of the tracks came out very thin, but I thought this is not a problem because HxC FDE works excellent on a PC.
and data/ctrl lines ? voltage divider (resistors) are ok ?

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