Swordfish

Well, I'm not sure what the issue is you're seeing.
I just created a 12000 byte file and read it using SD.ReadByte() in a loop until EOF, and it worked for me.

This with SD_OPTIMIZE = true, 18F27K40, clock=64, MSSP1, SPI clk = spiOscDiv4 (16MHz), and an SD card formatted as FAT32

G'day Guys

My apologies for not getting back to this sooner, ive been extremely busy over the xmas break with other projects.
Jerry i have tracked down my issue with the SD card reading and it was (as i pretty much suspected) my fault. My program includes a timer Interrupt and inside the Int routine was a call to another sub routine. The sub routine was very simple and i did not think to include the required context saving.. It wasn't until i read the help file on interrupts that it became clear how important it is..
I now have that sorted out 100%..

I do have some other questions regarding Interrupts, but i'll start a new thread for that..

Many thanks and Happy New year!

Lee

just to follow up... SDFileSystem (SDFS) 4.1.9 is included in the latest SF UPDATE 3_1_2023, so no need to download the 418 zip file

See using SDFileSystem with PPS (18FxxQ71 example) for details.