Baslinux mailing list

[sindi keesan <keesan AT sdf.lonestar.org>]

On Thu, 15 Feb 2007, Greg Mayman wrote:

> On Wed, 14 Feb 2007 16:21:48 +0000 (UTC), sindi keesan wrote:
>
> > I tested actual speed by downloading a 1MB pdf file from a fast site.
> > Average speed 2Kbyte/sec = 16 KBit/sec
>
> 2kbytes/sec = 20 kbits/sec, as every byte has one start bit and
> one stop bit added for synchronising purposes, making a total of
> 10 bits/byte.

Thanks.  Over a 14.4Kilobits/sec connection I was getting up to 1630 
(before the serial port buffer filled up?) falling gradually to 1495 
bytes/sec upload, not 1440 bytes/sec - why?  This comes out closer to 9 
than 10.  Maybe on a longer transfer it would have been 1440 by the end.

> I remember this well from the days when we used to make our own
> 300 baud serial ports and "Kansas City" modems for bulk storing
> data on audio cassettes.

Out of what?

> .  /     \     from Greg Mayman, in Adelaide, South Australia
> .  \_,-*_/     "Queen City of The South"    34:55 S  138:36 E

I have been reading on northbridges and southbridges.  Northbridge is 
closest to the cpu.  USB and sound are on the southbridge, which is 
connected to something via a super I/O.  When the hard drive went bad 
maybe it affected the super I/O (tho new hard drives still work fine with 
the controller once you turn on prefetch and block mode).  I think the 
super I/O controls the serial port (which is acting bad).  Floppy 
controller and parallel port act okay. The USB and maybe the onboard sound 
are also bad.  The northbridge handles the faster functions.

The computer with flakey floppy controller (works in DOS, sometimes in 
linux) has a bad serial controller.  Too bad they don't put in enough ISA 
slots any more to replace problems with ISA controller cards.  Another 
computer with failing onboard IDE controller also stopped booting.  Serial 
problems don't usually seem to damage other parts of the board - must be 
lightning striking just that part of it.  So bad-serial computers stay 
fixed once you replace the serial controller.  This 1.2 GHz seems stable 
now apart from modem problems.