Date   : Mon, 10 Aug 2009 07:38:48 +0100
From   : info@... (Sprow)
Subject: Level 4 FS Y2K query

In article <4A7F7246.8040600@...>,
   Rick Murray <rick@...> wrote:
> No problems anticipated. The rollover is something like 2108. I'll be 
> long-gone by then. ?

Centiseconds since 1900 epoch 5 byte time lasts until 2248.

> What worries me, however, is this little comment in the RISC OS sources:
>
>    ; Year should be >=1995, < 20
>    ; (2020 is arbitrary, but everything breaks soon after that)
>            MOV     R0, #YearCMOS+1
>            BL      Read
>            TEQ     R0, #19
>            BNE     check20
>
> [in RiscOS.Sources.Kernel.s.NewReset on lines 762 to 767]
>
> What the hell?!?!? 

Don't worry, if you scroll up you'll see it says

 [ ValidateCMOS :LAND: STB

which means that that CMOS corruption check only occurs for set top boxes.
Every set top box Acorn/Pace made will be long since in landfill by then.

> The year 2020 is too damn close to see things like 
> that in the sources.

They're referring to Unix seconds since 1970 epoch 4 byte time, that only
lasts until 2038 since it's a signed integer. All sorts of things use Unix 4
byte time, eg. on RISC OS the network stack.
Mainstream Unix is already working on changing to 64 bit time which gives
another 4 billion * 68 years.

In article <Marcel-1.53-0809212440-9eexSBG@...>,
   Johan Heuseveldt <johan@...> wrote:
> > All 8 bits of the common FS attributes have already been used up, so 
> > there's no where left to store the flag.
>
> Perhaps?

0      Local read access
1      Local write access
2      Execute only (RISC OS ADFS ignores this on read and clears on write)
3      Locked
4      Public read access
5      Public write access
6      Hidden (Filer+)
7      Application (Filer+)

Filer+ appears to be a 3rd party patch to add some extras to the desktop
filer so arguably bits 6 & 7 are unallocated,
Sprow.