What the difference between OS 3.5 and OS 4?

[Legodude522]

As far as I can remember most apps would work with OS 3.5 and OS 4 but not below that. And the OS looked the same except for really minor touches. Was there any major difference at all?

[ahsirg]

OS 4 had expansion memory support

[Legodude522]

Huh? So did 3.5 on the Visors didn't it?

[alt236]

You had to use a memplug cartridge in visors to access external memory. It installed the necessary (proprietary) drivers and files.
It wasn't built into the OS as far as I remember.

[Legodude522]

I thought the OS was originally built with support for 2 slots for external memory. I'll have to check on that.

[philpalm]

Checking my palm inventory the Palm m505 has version 0s 4.0, the Clie s-360 has version 4.0 and the Clie sl-10 has version 4.1 (for hi-res).

The Palm IIIc is another verion of OS 3(not sure what verion) for color but maybe there are other versions for the early Tungsten models?

[alt236]

Check the wiki entry (http://en.wikipedia.org/wiki/Palm_os) it has a pretty comprehensive list of the OS changes.

[potter]

Palm OS 4.0 supported VFS (Virtual? File System), basically removable media which had a FAT file system on it, first seen on the m500. The Visors (Palms OS 3.1 & 3.5) did support removable memory (Spring Boards) however they uses the same memory structure as the internal memory of the Palm. Later there were springboards that supported removable media such as Compact Flash and SD cards, and the VFS API was ported to it. But originally the VFS APIs were the primary feature of Palm OS 4.0 not found in 3.X.

Hmm, but how did the TRGpro fit in all of this? It supported removable memory that had the FAT file system (CF cards), but pre-dated the m500 and CF springboard. Probably it had it's own FS API.