How to create an embedded floppy drive using SD card.

[magnatro]

hey,
I need some inputs in creating a "virtual hardware" FDD drive using some SD card and a PIC micro controller.I have a PIC18f4550 with me and i know it has sufficient RAM for the SD interface? then how do I confuse the windows to have a FDD present in its hardware.. 1.44 MiB is enough for me. any help?

 

[Pommie]

Have a look at the **broken link removed**. It's rather convoluted but can be made to work.

Mike.

 

[wkrug]

I've done some similar with an ATMEGA32 Controller.
But the input is an serial signal.
You need a free RAM space in the Controller of 512 Byte to handle a complete cluster of the sd card.
It works up to Card sizes of 1024kByte. At bigger SD Cards the Cluster size is 1024 or 2048 Bytes.
At AVR i used a free library from the internet for FAT and Card Handling.

SD Cards normally work at 3.3V, so you have to include a level shifter.

I dont know, how to simulate a Floppy with an Microcontroller.
Perhaps you can find a Library in the Internet ?

I've searched a little bit and found that:
**broken link removed**

 

[Pommie]

I did actually get a pic to appear as a USB drive about 3 years ago. Details in this thread. As you only need a small drive you could just use serial EEPROM instead of an SD card.

Mike.

 

[magnatro]

I did an interface with the SD card once suing PIC 18f4550, but the problem is, as the floppy drives are now obsolete, there is a severe short supply problem here. even for the usb ones. if i can some how make an interface which "confuse" the windows that there is a floppy drive then my requirement is fulfilled. its an odd requirement, but the time and $ for developing new software for a small need is far far greater.

 

[Ian Rogers]

If you don't want to go down the USB route.... Old speccy 128 users have a web site with hard drive interfaces, floppy interfaces AND SD interfaces....They got the SD card to act as a floppy or even a hard drive...interfaces