9fans - fans of the OS Plan 9 from Bell Labs
 help / color / mirror / Atom feed
* Re: [9fans] punched cards live
@ 2008-11-04 15:25 Eris Discordia
  0 siblings, 0 replies; 8+ messages in thread
From: Eris Discordia @ 2008-11-04 15:25 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

> i think it's a tradition at this point to use 0x20 and not 0x00 to
> fill a fixed-with signature.  ata identify device uses 0x20 to fill
> out fixed-width fields like the serial number.  i'd be interested
> where this tradition popped up.  0 would make more sense.

I risk being wrong--as always--and say it must have popped up in a normal
ASCII environment. 0x20 = 32, the ASCII code point for a simple whitespace.
BIOS routines know how to display a whitespace, or any ASCII character, in
text mode. I remember somewhere back in time I could load AL with an ASCII
character, call interrupt 0x0A service 0x0E, and have the character printed
on the screen and the cursor moved one character to the right. This was
(is?) fairly standard and time-proven. And it worked (works?) everywhere,
at least in the PC world.

--On Monday, November 03, 2008 7:06 AM -0500 erik quanstrom
<quanstro@quanstro.net> wrote:

>> This courtesy of the ACPI spec: ""RSD PTR " (Notice that this
>> signature must contain a trailing
>> blank character.)"
>>
>> So where do we get the guys who design this stuff? Can we send them
>> back? Or put them in an infinite loop in a time machine (oh wait see
>> the subject).
>
> i think it's a tradition at this point to use 0x20 and not 0x00 to
> fill a fixed-with signature.  ata identify device uses 0x20 to fill
> out fixed-width fields like the serial number.  i'd be interested
> where this tradition popped up.  0 would make more sense.
>
> - erik
>
>







^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [9fans] punched cards live
@ 2008-11-03 13:59 erik quanstrom
  0 siblings, 0 replies; 8+ messages in thread
From: erik quanstrom @ 2008-11-03 13:59 UTC (permalink / raw)
  To: john, 9fans

> It's the ACPI Secure Computing Initiative:  fixed input format == no
> buffer overflow vulnerabilities.  Long live Herman Hollerith!
>

if bios wants to own the os, using buffer overflow in acpi
seems like more effort than necessary.

- erik



^ permalink raw reply	[flat|nested] 8+ messages in thread
* [9fans] punched cards live
@ 2008-11-03  7:01 ron minnich
  2008-11-03 12:06 ` erik quanstrom
  2008-11-03 13:37 ` John DeGood
  0 siblings, 2 replies; 8+ messages in thread
From: ron minnich @ 2008-11-03  7:01 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

This courtesy of the ACPI spec: ""RSD PTR " (Notice that this
signature must contain a trailing
blank character.)"

So where do we get the guys who design this stuff? Can we send them
back? Or put them in an infinite loop in a time machine (oh wait see
the subject).

ron



^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2008-11-05 10:39 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <1CF8271E0E449545D858FAB3@192.168.1.2>
2008-11-04 16:25 ` [9fans] punched cards live David Leimbach
2008-11-05 10:39   ` Eris Discordia
2008-11-04 15:25 Eris Discordia
  -- strict thread matches above, loose matches on Subject: below --
2008-11-03 13:59 erik quanstrom
2008-11-03  7:01 ron minnich
2008-11-03 12:06 ` erik quanstrom
2008-11-03 13:29   ` Brantley Coile
2008-11-03 13:37 ` John DeGood

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).