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matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10984

Posted: 07:02pm 24 Feb 2026

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One of the oddities of MMbasic is that filesnames on the A: drive are case sensitive. Nothing else is. This means that HELLO.bas is different to hello.bas is different to hello.BAS etc. Filenames on the B: drive are not case sensitive and doing something like copying a directory from A: to B: which contains both "HELLO.bas" and "Hello.BAS" will probably result in one of them going missing.
Unless anyone strongly objects, I propose to remove the case sensitivity of LFS on the A: drive.
Is this OK?

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 8587

Posted: 07:11pm 24 Feb 2026

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I'm all in favour.

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

circuit
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Joined: 10/01/2016
Location: United Kingdom
Posts: 297

Posted: 07:45pm 24 Feb 2026

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I agree - a sensible approach.

bfwolf
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Joined: 03/01/2025
Location: Germany
Posts: 176

Posted: 09:47pm 24 Feb 2026

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How do you plan to do that? I don't recall seeing a configuration switch like "IGNORECASE" when I used LittleFS in a project, and I just checked again and couldn't find anything about it in either the documentation or the source code.

One possible solution would be a dynamic option that converts all path names from MMBasic to lowercase before passing them to LittleFS.

But existing files with mixed case would then be invisible/inaccessible.

All in all, changing that is a delicate matter!

The oddity is actually inherent in FATFS, which only supports "ignorecase". I think I saw somewhere that NTFS can also be case-sensitive. Case sensitivity is standard for Unix filesystems anyway.

Regards, bfwolf.

phil99

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Joined: 11/02/2018
Location: Australia
Posts: 3030

Posted: 10:27pm 24 Feb 2026

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Quote But existing files with mixed case would then be invisible/inaccessible.

Presumably the introduction of this would involve a firmware update that will erase A:, as some previous ones have, so there won't be any existing files.

Quote Case sensitivity is standard for Unix filesystems anyway.

And that is fine as it does so consistently, but on the Pico there is inconsistency.
In MMBasic and B: case is ignored so a change makes sense.

As for the method of changing it another possible solution, with the aid of Claude, may be to change LittleFS itself, rather than the interface to it.
Converting all path names from MMBasic to lowercase before passing them to LittleFS may require a place to store the names with case intact to match the way B: behaves.
For the user interface it displays the original character cases. A hidden file that mirrors the FAT / ToC but with cases preserved might work.

No doubt Peter will find the best method.
.
Edited 2026-02-25 10:36 by phil99

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