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Author Topic: Arduino-Based Amiga Floppy Disk Reader  (Read 2504 times)

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Offline lar3ry

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Arduino-Based Amiga Floppy Disk Reader
« on: July 27, 2017, 11:04:39 PM »
Looks like a great project, Rob.
Do you think that most PCs will handle 1,000,000 baud on a USB serial port?
The reason I ask is that when I run ArduinoFloppyReaderWin, using the same port as I used to program the sketch, I get what appears to be conflicting indications.

The drive light comes ON and the disk spins as soon as I click Start Copy, but after a short time, I get Unable to open COM port.

This suggests to me that I am communicating with the Arduino Uno, but that something else is causing it to lose the connection.
Any ideas?

If it turns out that I can't use my COM port at a million baud (I never in my life would have thought I'd ever use those two words next to each other), I think I will try a little different tack. I have a Mega 2560, and think I can get by with using a lower COM port speed. I know for sure I can handle 115200, and it is likely I can handle 250000. I figure there are two ways of doing this.

Because the lower baud rate is insufficient to keep up with the raw data rate of fthe disk, I can buffer the data in one of two ways.

1. The Mega 2560 has 8K bytes of RAM. I should be able to buffer single blocks. The limitation would be in how many blocks I can read in to the available RAM. I could then transfer them, and grab the next block(s). Might be a tad slow, so my second plan might be better.

2. I have a 32K*8 Static RAM chip that I could use to buffer 1 track at a time. If I understand things correctly, one track will be something lile 1900 * 11 bytes, requiring just under 21K. I also have a few 512K * 8 RAM chips on the way, one of which should allow me to buffer 25 tracks at a time.

I would use your sketch, modified, but I have been unable to compile your ArduinoFloppyReaderWin program. the file stdafx.cpp is missing, and I get a message saying it can't find build tool V141, which is likely because I am using VS Express 2015.

If I can't figure that out, I'll drop back into VB (one of my comfort zones - assembler and VB).

Any coments, corrections or ideas welcome.
« Last Edit: July 27, 2017, 11:08:50 PM by lar3ry »
 

Offline lar3ry

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Arduino-Based Amiga Floppy Disk Reader
« Reply #1 on: August 03, 2017, 10:58:03 PM »
UPDATE

Well, it looks like I had problems with the floppy drive itself. For some reason this manifested as a COM problem.

I found it by reducing the baud rate to 115200 and using the serial monitor to send commands. This showed several problems, all to do with a bad floppy drive. I managed to find a few more drives, and these worked better.

So now, I can use the programs and sketch that Rob posted.

I do seem to get a lot of errors yet, and i don't really know if it's the floppies themselves or the drives. I have tested on three drives, and some are better than others. They are cheap, so I don't mind picking up a few more. I am  also going to work on my wiring and shielding in case some of the errors are in the drive to Arduino interface.