[Coco] bug in Basic09

[Gene Heskett]

On Saturday 12 August 2006 06:54, Bob Devries wrote:
>People, I've come across a bug in Basic09 that is related to our Y2K
>problem.
>
>It is the DATE$ function.
>If I issue the command:
>
>PRINT DATE$
>
>in my Basic09 programme, it returns:
>:6/08/12 20:50:00
>
>It *should* either return:
>
>106/08/12 20:50:00
>or
>06/08/12 20:50:00
>or
>2006/08/12 20:50:00
>
>Has anyone looked at patching Basic09 (and RunB) to deal with this issue?
>
There are some 'fixed' clocks and date display utils about, I even wrote 
one of them.  But basic09 and runb were never fixed.  The problem is the 
the era for os9 starts with the year 1900, and no one when that code was 
being written, had any idea there would still be working systems in the 
years>1999.

The size of the year in the date packet the system maintains is a byte 
only, which limits the year to 1900+255 in range.  We haven't exceeded 
that (yet, and I won't be around when we do), but no provision was ever 
made to handle that binary to decimal conversion where the year was 
>99decimal.

ISTR in my own fixes, I used 1999 as a breakpoint, subbing 100decimal from 
values>63hex, and then fixed the date utility so it added 100decimal if 
the result of that subtraction was <1970.  But fixing that date utility 
didn't of course fix the basic09 or runb internal versions.

The clock module itself doesn't care if the year byte goes greater than 
64hex (year =100+1900=2000), so its as happy as a clam clear up to dec 31 
2155, at which point it will simply roll over to 00hex as there's no check 
for a carry there.  At that point, the fixed date utils will be wrong 
until 1970 rolls around again 70 years later.  By then I have serious 
doubts there will be any functioning coco/os9 systems left, nor anyone who 
might care.

Dissing basic09 or runb would be quite a project in itself, and I have no 
idea if its ever been done.  Once dissed, then one would search thru the 
dis to find the os9 f$gettim call and begin editing it there.  If a good 
dis already exists, then this would be 80% easier.

To Boisy, does such a beast exist in your archives?  Maybe after 7 years of 
this, someone might be able to effect a fix?

>--
>Regards, Bob Devries, Dalby, Queensland, Australia
>
>Isaiah 50:4 The sovereign Lord has given me
>the capacity to be his spokesman,
>so that I know how to help the weary.
>
>website: http://www.home.gil.com.au/~bdevasl
>my blog: http://bdevries.invigorated.org/

-- 
Cheers, Gene
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