30 Sep
2002
30 Sep
'02
6:37 p.m.
Got a question...
I have just received an original IBM PC; actually, 2
of them (one had to be parted out). I still haven't
checked the BIOS date, but the machine does have an
origianl Intel 8088 and the power supply appears to be
the original design. Here is the crux of the
problem...
I want to refit the machine with a 720 KB 3 1/2"
drive. This was a fairly easy mod that we used to
perform on XT's, but it seems to have problems finding
the drive. Anybody out there have any experience with
this?
Robert
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30 Sep
30 Sep
6:59 p.m.
I have just received an original IBM PC; actually, 2
[...]
I want to refit the machine with a 720 KB 3 1/2"
drive.
Ugh! Am I the only one that finds this idea completely
repugnant?
The whole point of having an original 5150 is that it is
*original*. If you want a PC with a 3.5" drive, you
can find those *anywhere*.
1 Oct
1 Oct
12:56 a.m.
Don't be such a racist :-)
You cannot always have software on 5.25 drives, or 5.25 drives on your ATX
box. Is it so bad to be able to use a 3.5'' floppy on an old system? it's
not necessary a sacrilege to use an old system, otherwise useless (without
any software)
Ugh! Am I the only one that finds this idea
completely
repugnant?
The whole point of having an original 5150 is that it is
*original*. If you want a PC with a 3.5" drive, you
can find those *anywhere*.
12:51 a.m.
use a power cable splitter to get the proper power plug, then a flat cable,
with IDC connector instead the edge connector. I believe you could use a
3.5'' 1.44 drive right away (I did with a very very very old PC compatible).
I think it should be better to have the 3.5'' as a second device.
I have just received an original IBM PC; actually, 2
of them (one had to be parted out). I still haven't
checked the BIOS date, but the machine does have an
origianl Intel 8088 and the power supply appears to be
the original design. Here is the crux of the
problem...
I want to refit the machine with a 720 KB 3 1/2"
drive. This was a fairly easy mod that we used to
perform on XT's, but it seems to have problems finding
the drive. Anybody out there have any experience with
this?
Robert
4:55 a.m.
On Mon, 30 Sep 2002, Robert Little wrote:
Got a question...
I have just received an original IBM PC; actually, 2
of them (one had to be parted out). I still haven't
checked the BIOS date, but the machine does have an
origianl Intel 8088 and the power supply appears to be
the original design. Here is the crux of the
problem...
I want to refit the machine with a 720 KB 3 1/2"
drive. This was a fairly easy mod that we used to
perform on XT's, but it seems to have problems finding
the drive. Anybody out there have any experience with
this?
Did you set the dipswitches for number of drives?
There is literally NO difference between the PC and XT for installing a
floppy drive. What EXACTLY do you mean by "problems finding the
drive"? What DOS error message do you get? What Int13h error number do
you get?
If you are concerned about maintaining the pristine "original" nature of
it, then install the drive as the third or fourth (external) drive. The
original PC and XT disk controllers had a DC37 connector for that. OR,
find one of the "rare" IBM original 3.5" retrofit kits with the big
faceplate.
If you want MS/PC DOS support of it, then you need to use version 3.20 or
above, and use DRIVER.SYS. (DRIVPARM is present in both MS-DOS, and
PC-DOS (undocumented), but does not work properly with those original IBM
BIOSes) Some OEM versions of 2.11 supported 3.5" drives, but those were
custom versions, and MODE.COM, etc. may not be right for it. OR, use
third party drivers, such as John Henderson's (Tall Tree systems)'
JFORMAT. , or Manzanita, or, ...
--
Grumpy Ol' Fred
8:07 a.m.
New subject: DRIVPARM
A quick puzzle:
When IBM came out with PC-DOS 3.20 (the first version to support 720K
3.5"), it documented DRIVER.SYS, but did not mention DRIVPARM.
MS-DOS did document DRIVPARM.
(NOTE: some OEM versions of 2.11 had direct support of 720K, often INSTEAD
of 360K)
When using MS-DOS on "real" IBM PC, XT, AT, and PS/2, DRIVPARM would
produce "unrecognized command in CONFIG.SYS".
When using PC-DOS on "real" IBM PC, XT, AT, and PS/2, DRIVPARM would
produce "unrecognized command in CONFIG.SYS".
When using PC-DOS on "real" generic clones, DRIVPARM would
work.
When using MS-DOS on "real" generic clones, DRIVPARM would
work.
When I put copies of the IBM BIOS into a generic clone, DRIVPARM would no
longer work.
Although I can't claim that my sample was enough to be truly certain, it
certainly implies that DRIVPARM was incompatible with the IBM BIOS.
The error message that was produced does not seem to be accurate as to
what the problem was.
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
8:20 a.m.
New subject: DRIVPARM
Please correct me if I am wrong, but on the IBM PC motherboard there should
be some jumpers or a dip switch array. Am I wrong? could anybody provide me
with the functionality of these jumpers or switches?
A quick puzzle:
<....>
Although I can't claim that my sample was enough
to be truly certain, it
certainly implies that DRIVPARM was incompatible with the IBM BIOS.
The error message that was produced does not seem to be accurate as to
what the problem was.
8:39 a.m.
New subject: PC SWITCHES (was: DRIVPARM
On Tue, 1 Oct 2002, Voyager wrote:
Please correct me if I am wrong, but on the IBM PC
motherboard there should
be some jumpers or a dip switch array. Am I wrong? could anybody provide me
with the functionality of these jumpers or switches?
On the PC, there are TWO switch packs. One for memory size, and one for
various option, including number of drives, 8087 installed, etc.
On the XT, there is ONE switch pack, and memory is determined during POST.
Int 11h maps the switches into AX.
Int 12h reports the amount of RAM.
1, 7, 8 are the number of drives
2 is co-processor (half are set wrong)
3, 4 is RAM on motherboard
5, 6 is monitor type
--
Grumpy Ol' Fred cisin(a)xenosoft.com
9:44 a.m.
New subject: PC SWITCHES (was: DRIVPARM
Thanks!
But, could you please give me more details on the ON-OFF and meaning? for
example the 1,7,8 is for the number of drives. Up to 8 drives?
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <cctalk(a)classiccmp.org>
Sent: Tuesday, October 01, 2002 11:40 PM
Subject: PC SWITCHES (was: DRIVPARM
On Tue, 1 Oct 2002, Voyager wrote:
> Please correct me if I am wrong, but on the IBM PC motherboard there
should
> be some jumpers or a dip switch array. Am I
wrong? could anybody provide
me
with the
functionality of these jumpers or switches?
On the PC, there are TWO switch packs. One for memory size, and one for
various option, including number of drives, 8087 installed, etc.
On the XT, there is ONE switch pack, and memory is determined during POST.
Int 11h maps the switches into AX.
Int 12h reports the amount of RAM.
1, 7, 8 are the number of drives
2 is co-processor (half are set wrong)
3, 4 is RAM on motherboard
5, 6 is monitor type
--
Grumpy Ol' Fred cisin(a)xenosoft.com
11:29 a.m.
New subject: PC SWITCHES (was: DRIVPARM
On Wed, 2 Oct 2002, Voyager wrote:
Thanks!
But, could you please give me more details on the ON-OFF and meaning? for
example the 1,7,8 is for the number of drives. Up to 8 drives?
FOUR drives.
Switch 1 was whether or not there were any drives (probably actually
whether it should attempt to boot from floppy), and 7 and 8 set how
many.
More detail than that will have to wait until sometime when I have the
technical reference manual handy.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
11:48 a.m.
New subject: PC SWITCHES (was: DRIVPARM
On Tue, 1 Oct 2002, Fred Cisin (XenoSoft) wrote:
On Wed, 2 Oct 2002, Voyager wrote:
There is a small program, the PC Magazine System Checkout Utility,
called STATUS.COM which should answer many of your questions as well
as show you the "status" of your machine's switch settings. I would
guess that it is still around on the web somewhere that google can
find it. If not, I can email it to you.
- don
Thanks!
But, could you please give me more details on the ON-OFF and meaning? for
example the 1,7,8 is for the number of drives. Up to 8 drives?
FOUR drives.
Switch 1 was whether or not there were any drives (probably actually
whether it should attempt to boot from floppy), and 7 and 8 set how
many.
More detail than that will have to wait until sometime when I have the
technical reference manual handy.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
12:03 p.m.
New subject: PC SWITCHES (was: DRIVPARM
On Tue, 1 Oct 2002, Don Maslin wrote:
On Tue, 1 Oct 2002, Fred Cisin (XenoSoft) wrote:
It has one problem though. It is confused as to OFF and ON!!!
- don
On Wed, 2 Oct 2002, Voyager wrote:
There is a small program, the PC Magazine System Checkout Utility,
called STATUS.COM which should answer many of your questions as well
as show you the "status" of your machine's switch settings. I would
guess that it is still around on the web somewhere that google can
find it. If not, I can email it to you.
- don Thanks!
But, could you please give me more details on the ON-OFF and meaning? for
example the 1,7,8 is for the number of drives. Up to 8 drives?
FOUR drives.
Switch 1 was whether or not there were any drives (probably actually
whether it should attempt to boot from floppy), and 7 and 8 set how
many.
More detail than that will have to wait until sometime when I have the
technical reference manual handy.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
12:25 p.m.
New subject: PC SWITCHES (was: DRIVPARM
On Tue, 1 Oct 2002, Don Maslin wrote:
> There is a small program, the PC Magazine System
Checkout Utility,
> called STATUS.COM which should answer many of your questions as well
> as show you the "status" of your machine's switch settings. I would
> guess that it is still around on the web somewhere that google can
> find it. If not, I can email it to you.
It is presumably just doing an INT 11h and parsing the bits of AX.
I used to assign that as homework to my assembly language classes.
That gave excellent practice with using AND, SHR, etc.
But the switch settings no longer provide reliable info.
Hmmmm. maybe I should assign reading the CMOS and displaying the
information that it represents.
It has one problem though. It is confused as to OFF
and ON!!!
Each of the switches is switched to "open" for "YES". Therefore,
"logical
ON" became "electrical off"
One of the first rounds of IBM's "Guide to Operations" had it backwards
for the setting for the "Math coprocessor present" switch! That resulted
in half of the machines being set wrong.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
11:31 a.m.
New subject: PC SWITCHES (was: DRIVPARM
http://www.rci.rutgers.edu/~preid/pcxtsw.htm
IBM PC
Switch block 1, near center of board:
* Switch 1
* off = Boot from floppy
* ON = Don't boot from floppy (goes to Cassette BASIC in ROM)
* Switch 2
* off = 8087 Math Chip installed
* ON = 8087 NOT installed
* Switch 3,4
* ON,ON = One bank of memory
* off,ON = Two banks
* ON,off = Three banks
* off,off = Four banks
* Switch 5,6
* off,off = MDA (or Hercules) Video
* off,ON = 40 column CGA
* ON,off = 80 column CGA
* ON,ON = No video or special (EGA, VGA)
* Switch 7,8
* ON,ON = 1 floppy drive
* off,ON = 2 flops
* ON,off = 3 flops
* off,off = 4 flops
Switch block 2, near power supply:
Switches 1, 2, 3, 4, 5 = Total memory installed
* Memory installed - sw1 2 3 4 5
* 16K = ON ON ON ON ON
* 32K = ON ON ON ON ON
* 48K = ON ON ON ON ON
* 64K = ON ON ON ON ON
* 96K = off ON ON ON ON
* 128K = ON off ON ON ON
* 160K = off off ON ON ON
* 192K = ON ON off ON ON
* 224K = off ON off ON ON
* 256K = ON off off ON ON
* 288K = off off off ON ON
* 320K = ON ON ON off ON
* 352K = off ON ON off ON
* 384K = ON off ON off ON
* 416K = off off ON off ON
* 448K = ON ON off off ON
* 480K = off ON off off ON
* 512K = ON off off off ON
* 544K = off off off off ON
* 576K = ON ON ON ON off
* 608K = off ON ON ON off
* 640K = ON off ON ON off
* Switches 6, 7, 8
* Always off
Jeffrey H. Ingber (jingber(a)ix.netcom.com)
On Tue, 2002-10-01 at 17:40, Voyager wrote:
Thanks!
But, could you please give me more details on the ON-OFF and meaning? for
example the 1,7,8 is for the number of drives. Up to 8 drives?
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <cctalk(a)classiccmp.org>
Sent: Tuesday, October 01, 2002 11:40 PM
Subject: PC SWITCHES (was: DRIVPARM
On Tue, 1 Oct 2002, Voyager wrote:
> Please correct me if I am wrong, but on the IBM PC motherboard there
should
> be some jumpers or a dip switch array. Am I
wrong? could anybody provide
me
with the
functionality of these jumpers or switches?
On the PC, there are TWO switch packs. One for memory size, and one for
various option, including number of drives, 8087 installed, etc.
On the XT, there is ONE switch pack, and memory is determined during POST.
Int 11h maps the switches into AX.
Int 12h reports the amount of RAM.
1, 7, 8 are the number of drives
2 is co-processor (half are set wrong)
3, 4 is RAM on motherboard
5, 6 is monitor type
--
Grumpy Ol' Fred cisin(a)xenosoft.com
8118
days inactive
8118
days old
13 comments
6 participants
participants (6)
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cisin＠xenosoft.com -
donm＠cts.com -
eric＠brouhaha.com -
jingber＠ix.netcom.com -
robert_little_2000＠yahoo.com -
voyager＠hol.gr