Originally Posted by ArkM

Is it so hard job to correct obvious errors: you get compiler messages on wrong function arguments: fread and fwrite want POINTERS to target/source data areas (&d - not d, &b - not b))!

Use code tag properly:
[code=c]
source
[/code]

Never use dangerous gets function: it does not check target buffer size. Use fgets instead of gets:

Help with Code Tags

c Syntax (Toggle Plain Text)

fgets(fn,sizeof fn,sdtin);

fgets(fn,sizeof fn,sdtin);

With gets you program crashed if the file name length is greater than 49.

Don't forget to append carriage return:

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c Syntax (Toggle Plain Text)

printf("\nFile saved\n");

printf("\nFile saved\n");

Avoid using of non-standard function flushall().