15 Mar
2001
15 Mar
'01
5:19 a.m.
Can anybody help this guy out? If so then reply directly to him.
---------- Forwarded message ----------
Date: Tue, 13 Mar 2001 13:09:43 -0800
From: Lincoln Spector <lincoln(a)dnai.com>
Subject: Looking for Someone with IBM PC
Hi. I'm writing an article for PC World on the 20th anniversary of the IBM
PC. I'm looking for someone with an original IBM PC (circa 1981) and DOS 1.0
on floppies.
I'm not trying to buy the computer. I would just like to talk to someone who
has one and might be willing to do a simple test on it for me.
Thank you,
Lincoln Spector
Journalist, Columnist, Humorist
510-548-3725
lincoln(a)dnai.com
www.thelinkinspector.com
15 Mar
15 Mar
7:44 a.m.
That message is two days old. In that time, we have contacted him, set up
the system needed, done the tests he wanted, done multiple followup
tests, and let the list know.
Just one remaining issue: does anyone know why the P.O.S.T. takes longer
(14 seconds) than it does with 64K (9 seconds)??
--
Grumpy Ol' Fred cisin(a)xenosoft.com
On Thu, 15 Mar 2001, Kevan Heydon wrote:
Can anybody help this guy out? If so then reply
directly to him.
---------- Forwarded message ----------
Date: Tue, 13 Mar 2001 13:09:43 -0800
From: Lincoln Spector <lincoln(a)dnai.com>
Subject: Looking for Someone with IBM PC
Hi. I'm writing an article for PC World on the 20th anniversary of the IBM
PC. I'm looking for someone with an original IBM PC (circa 1981) and DOS 1.0
on floppies.
I'm not trying to buy the computer. I would just like to talk to someone who
has one and might be willing to do a simple test on it for me.
Thank you,
Lincoln Spector
Journalist, Columnist, Humorist
510-548-3725
lincoln(a)dnai.com
www.thelinkinspector.com
8:19 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
Sorry, slipped up on my question. should read:
Just one remaining issue: does anyone know why the P.O.S.T. takes longer
WITH 16K (14 seconds) than it does with 64K (9 seconds)??
Why would MORE memory take LESS time?
--
Grumpy Ol' Fred cisin(a)xenosoft.com
8:26 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
On Thu, Mar 15, 2001 at 11:19:36AM -0800, Fred Cisin (XenoSoft) (cisin(a)xenosoft.com)
wrote:
Sorry, slipped up on my question. should read:
Just one remaining issue: does anyone know why the P.O.S.T. takes longer
WITH 16K (14 seconds) than it does with 64K (9 seconds)??
Why would MORE memory take LESS time?
More memory at the same speed, or more, faster memory?
-Rich
--
------------------------------ Rich Lafferty ---------------------------
Sysadmin/Programmer, Instructional and Information Technology Services
Concordia University, Montreal, QC (514) 848-7625
------------------------- rich(a)alcor.concordia.ca ----------------------
8:49 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
On Thu, 15 Mar 2001, Rich Lafferty wrote:
Same processor speed (4.77 MHz)
Same memory speed. Actually, same memory; 5150 dip switches permit
limiting how much of the memory the PC sees.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
Just one
remaining issue: does anyone know why the P.O.S.T. takes longer
WITH 16K (14 seconds) than it does with 64K (9 seconds)??
Why would MORE memory take LESS time?
More memory at the same speed, or more, faster memory? 
9:55 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
More memory at the same speed, or more, faster memory?
Same processor speed (4.77 MHz)
Same memory speed. Actually, same memory; 5150 dip switches permit
limiting how much of the memory the PC sees. 
18 Mar
18 Mar
5:47 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
I believe the original PC checked EVERY memory location and the later
machines checked every 10th(?) memory location.
Joe
At 02:26 PM 3/15/01 -0500, you wrote:
On Thu, Mar 15, 2001 at 11:19:36AM -0800, Fred Cisin
(XenoSoft)
(cisin(a)xenosoft.com) wrote:
Sorry, slipped
up on my question. should read:
Just one remaining issue: does anyone know why the P.O.S.T. takes longer
WITH 16K (14 seconds) than it does with 64K (9 seconds)??
Why would MORE memory take LESS time?
More memory at the same speed, or more, faster memory?
-Rich
--
------------------------------ Rich Lafferty ---------------------------
Sysadmin/Programmer, Instructional and Information Technology Services
Concordia University, Montreal, QC (514) 848-7625
------------------------- rich(a)alcor.concordia.ca ----------------------
5:51 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
A very reasonable hypothesis. But an unreasonable situation!
This was the SAME MACHINE with different amounts of the same memory!
(with repeatable results)
--
Grumpy Ol' Fred cisin(a)xenosoft.com
On Sun, 18 Mar 2001, Joe wrote:
I believe the original PC checked EVERY memory
location and the later
machines checked every 10th(?) memory location.
Joe
At 02:26 PM 3/15/01 -0500, you wrote:
On Thu, Mar 15, 2001 at 11:19:36AM -0800, Fred
Cisin (XenoSoft)
(cisin(a)xenosoft.com) wrote:
>> Sorry, slipped up on my question. should read:
>> Just one remaining issue: does anyone know why the P.O.S.T. takes longer
>> WITH 16K (14 seconds) than it does with 64K (9 seconds)??
>>
>> Why would MORE memory take LESS time? 
7:31 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
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10:25 a.m.
New subject: P.O.S.T. issue (was: Looking for Someone with IBM PC (fwd)
On Sun, 18 Mar 2001, Tony Duell wrote:
I've had a quick look at the BIOS source listings
in the TechRef, and I
can't see any reason why the POST would be slower with 16K than with 64K.
The memory check tests the RAM in 16K blocks, no matter how the DIP
switches are set. The only difference I can see is that if you have <64K
memory (on the motherboard), it doesn't check the DIP switches to look
for memory in expansion slots. But this would speed up the POST for
smaller amounts of memory, and anyway, even an 8088 doesn't take 5s for a
single conditional test :-)
One of the differences between the PC (5150) and the XT is the presence on
the PC of a DIP switch for amount of memory (the XT goes by what it finds
in POST).
Would folk with PC (5150) mind:
set the switches for 16K RAM, and time the POST.
Then set the switches for 64K RAM and time it again.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
8528
days inactive
8531
days old
9 comments
6 participants
participants (6)
-
ard＠p850ug1.demon.co.uk -
bills＠adrenaline.com -
cisin＠xenosoft.com -
kevan＠heydon.org -
rich＠alcor.concordia.ca -
rigdonj＠intellistar.net