Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > alt.folklore.computers > #216133

Re: Remembering the HP-2000/A timeshare midnight rollover

Show all headers | View raw

On Thu, 31 Dec 2020 19:03:41 GMT, Charlie Gibbs
<cgibbs@kltpzyxm.invalid> wrote: 

> On 2020-12-31, David LaRue <huey.dll@tampabay.rr.com> wrote:
> 
>> Hello,
>>
>> During High School we had access to an HP-2000/Access timeshare
>> system.  I found that the system time wrapped oddly on New Year.  It
>> rolled over to December 32 of the same year.  The System Operator had
>> to manually update the date at the start of the new year.
>>
>> Were there other systems that didn't handle December to January
>> rollovers? 
> 
> Hell, early versions of MS-DOS didn't even handle midnight rollover
> reliably.  A 10-line BASIC program that shows date and time whenever
> either one changes would produce output with various combinations of
> some, all, or none of the following, depending on version, machine,
> and probably phase of the moon:
> 
> 12-24-1985 23:59:58
> 12-24-1985 23:59:59
> 12-24-1985 24:00:00
> 12-24-1985 00:00:00
> 12-25-1985 00:00:00
> 12-25-1985 00:00:01
> 
> Been there, done that, wrote nasty code to deal with it.
> 
> Fred Brooks, in _The Mythical Man-Month_, describes the decision to
> omit code that handled February 29 in leap years, to save 100 bytes.
> 
I tried searching for this and I got

https://chryss.eu/tag/software/
<Quote>
according to Brooks, who had been one of the the project’s managers in 
the 1960s, a typical second system. And to support his claim that it was 
overblown and wasteful, he offers this example:

For example, OS/360 devotes 26 bytes of the permanently resident date-
turnover routine to the proper handling of December 31 on leap years 
(when it is Day 366). That might have been left to the operator.
</Quote>


>> Happy 2021 everyone!
> 
> Same to you.
> 



-- 
Bah, and indeed, Humbug.

Back to alt.folklore.computers | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Remembering the HP-2000/A timeshare midnight rollover David LaRue <huey.dll@tampabay.rr.com> - 2020-12-31 13:21 +0000
  Re: Remembering the HP-2000/A timeshare midnight rollover Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-12-31 19:03 +0000
    Re: Remembering the HP-2000/A timeshare midnight rollover "Kerr-Mudd,John" <notsaying@127.0.0.1> - 2021-01-07 21:56 +0000

csiph-web