[sevensor]

> why 8.3 filenames

Why is that, exactly? I grew up in that era, I remember when floppies were actually floppy, and I've been well into computers ever since, but I don't believe I could tell you why. If I had to guess, I'd guess that FAT used a fixed number of bytes for each filename.

[northwest66]

Yep you got it. My first actual PCs (I don't count the Apricot PCs haha) were DOS 3.3, and I still remember the transition away from 33MB partitions although it's so long ago I can't remember if that came in with DOS 4.0 (abort abort!) or 5. I thought I was so cool having a PC with drives A B C D E F G H I.

[u801e]

I had a 486 PC with a 100 MB hard drive running Dos 5.x (can't recall the minor version). The hard drive was definitely a single partition.

[FranOntanaya]

Oh man, rich kids had a D: drive. The rest of us had to make do with A: and C:

[skookumchuck]

It was 6.3 before that. The PDP-10 system :-)

[kbob]

I don't know about PDP-10s. DEC's PDP-11 operating systems used a character set called RAD-50, short for radix (octal) 50, for filenames and various other purposes.

The (decimal) 40 characters were A-Z, 0-9, and four punctuation characters -- I don't remember which. Three characters could be stored in a 16 bit word, so a 6.3 filename required 3 words or 6 bytes. The '.' separator was not stored, of course.

The implementers of CP/M or one of those early PC OSes copied the idea but not the encoding and picked 8.3 as a slightly more usable size. Floppy drives were relatively capacious (!) so bigger filenames were reasonable.

The only reason I know this PDP-11 trivia is that end users could recompile the RT-11 kernel to save space, and DEC distributed the OS sources to enable that. The distributed version was written in assembler and had had comments stripped, so it wasn't quite like reading the Lions book, but you could read it if you really wanted to.

[HankB99]

Didn't that include a ';' and version number too? (Or was that later - RSX-11M on a PDP 11/23)

[skookumchuck]

I think that was later.

[jclulow]

It did.