29 Aug
2005
29 Aug
'05
7:28 p.m.
Hi everyone!
I have an old Portable PC that I put a 2MB memory card in, along with an EGA
card, sound card, and some other stuff. I'm doing my best to max it out.
Anyway, I'm having some trouble with hard disks. I have two hard disk
controllers: a Seagate ST02 SCSI/Floppy controller, and a Juko Labs D16-X
IDE controller. Now both of these cards work okay, except they recognize
some strange sizes for the disks. The only disk that seems to show up
correctly is a Quantum LP105S...the others I tried, all bigger than a gig,
are either not recognized, or recognized with the wrong size. This is also
the case with the IDE controller - everything is recognized at 10MB. I
purchased an LBA PRO card for my machine hoping to overcome the large disk
size problem, but all it does is freeze the machine...however, if I remove
the 8088 and replace it with a NEC V20, I get the banner for the hard disk
drive card, and THEN the machine freezes.
So my questions are:
1. Does anyone know a good solution for putting a large drive in an XT,
while still leaving it an XT?
2. Should I leave the V20 in? I've heard it has compatibility issues with
some programs, but I'm not solid on my information.
Regards,
Julian
29 Aug
29 Aug
4:25 p.m.
Hi everyone!
I have an old Portable PC that I put a 2MB memory card in, along with an EGA
card, sound card, and some other stuff. I'm doing my best to max it out.
Anyway, I'm having some trouble with hard disks. I have two hard disk
controllers: a Seagate ST02 SCSI/Floppy controller, and a Juko Labs D16-X
IDE controller. Now both of these cards work okay, except they recognize
some strange sizes for the disks. The only disk that seems to show up
correctly is a Quantum LP105S...the others I tried, all bigger than a gig,
are either not recognized, or recognized with the wrong size. This is also
the case with the IDE controller - everything is recognized at 10MB. I
purchased an LBA PRO card for my machine hoping to overcome the large disk
size problem, but all it does is freeze the machine...however, if I remove
the 8088 and replace it with a NEC V20, I get the banner for the hard disk
drive card, and THEN the machine freezes.
So my questions are:
1. Does anyone know a good solution for putting a large drive in an XT,
while still leaving it an XT?
2. Should I leave the V20 in? I've heard it has compatibility issues with
some programs, but I'm not solid on my information.
Regards,
Julian
This particlar can't handle this large due to decoding issues or
capacity issues (1GB is too large for 8088 than needed), either the
XT is a shoddy clone the TTL timings is not right if using a firmware
add on to handle large IDE capacities.
The SCSI is best for this if stuck with 8088. Otherwise keep under
500MB with IDE, not even 540, have to be under 500. Is the portable
standard XT or baby AT layout? Go with 286 or 386DX then everything
else will work as described. There are many 286 and 386 boards that
has XT mounting holes layouts. Choose carefully, there are so many
junk out there.
Cheers, Wizard
30 Aug
30 Aug
12:37 p.m.
On Mon, 2005-08-29 at 23:25 +0000, jpero at sympatico.ca wrote:
The SCSI is best for this if stuck with 8088.
Otherwise keep under
500MB with IDE, not even 540, have to be under 500. Is the portable
standard XT or baby AT layout? Go with 286 or 386DX then everything
else will work as described. There are many 286 and 386 boards that
has XT mounting holes layouts. Choose carefully, there are so many
junk out there.
Has anyone tried interfacing a CF card to 8-bit IDE? ATA IDE to CF
cards exist, aside from the practical reason that very few people would
buy such a thing, why not XT-IDE to CF adapter?
I guess the BIOS would have to be added to such an adapter.
CF cards are closer in size to what the old machines work with, and they
are generally cheap.
-- John.
12:47 p.m.
I actually have one of these adapters, but have yet to try it because I need
a CF card. Maybe when I get some extra cash I'll try it.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of John R. Hogerhuis
Sent: Tuesday, August 30, 2005 2:38 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: XTs and large hard disks
On Mon, 2005-08-29 at 23:25 +0000, jpero at sympatico.ca wrote:
The SCSI is best for this if stuck with 8088.
Otherwise keep under
500MB with IDE, not even 540, have to be under 500. Is the portable
standard XT or baby AT layout? Go with 286 or 386DX then everything
else will work as described. There are many 286 and 386 boards that
has XT mounting holes layouts. Choose carefully, there are so many
junk out there.
Has anyone tried interfacing a CF card to 8-bit IDE? ATA IDE to CF cards
exist, aside from the practical reason that very few people would buy such a
thing, why not XT-IDE to CF adapter?
I guess the BIOS would have to be added to such an adapter.
CF cards are closer in size to what the old machines work with, and they are
generally cheap.
-- John.
1 Sep
1 Sep
10:25 a.m.
On Tue, 2005-08-30 at 14:47 -0500, Julian Wolfe wrote:
I actually have one of these adapters, but have yet to
try it because I need
a CF card. Maybe when I get some extra cash I'll try it.
Browse here from time to time, or subscribe:
http://www.freeafterrebate.info/index.php?topic=hardware
Typically < 256Meg compact flash cards go for "free after rebate" all
the time.
I assume the adapter you have is ATA IDE to CF, not XT-IDE?
-- John.
30 Aug
30 Aug
4:26 p.m.
Hi everyone!
I have an old Portable PC that I put a 2MB memory card in, along with an EGA
card, sound card, and some other stuff. I'm doing my best to max it out.
Anyway, I'm having some trouble with hard disks. I have two hard disk
controllers: a Seagate ST02 SCSI/Floppy controller, and a Juko Labs D16-X
IDE controller. Now both of these cards work okay, except they recognize
some strange sizes for the disks. The only disk that seems to show up
correctly is a Quantum LP105S...the others I tried, all bigger than a gig,
are either not recognized, or recognized with the wrong size. This is also
the case with the IDE controller - everything is recognized at 10MB. I
purchased an LBA PRO card for my machine hoping to overcome the large disk
size problem, but all it does is freeze the machine...however, if I remove
the 8088 and replace it with a NEC V20, I get the banner for the hard disk
drive card, and THEN the machine freezes.
So my questions are:
1. Does anyone know a good solution for putting a large drive in an XT,
while still leaving it an XT?
2. Should I leave the V20 in? I've heard it has compatibility issues with
some programs, but I'm not solid on my information.
Regards,
Julian
This particlar can't handle this large due to decoding issues or
capacity issues (1GB is too large for 8088 than needed), either the
XT is a shoddy clone the TTL timings is not right if using a firmware
add on to handle large IDE capacities. The SCSI is best for this if stuck with 8088.
Otherwise keep under
500MB with IDE, not even 540, have to be under 500. Is the portable
standard XT or baby AT layout? Go with 286 or 386DX then everything
else will work as described. There are many 286 and 386 boards that
has XT mounting holes layouts. Choose carefully, there are so many
junk out there.
The problem with this is that the keyboard interface changed between the
XT and AT. And you pretty much have to stick with the original XT
keyboard on a 5155...
-tony
29 Aug
29 Aug
7:39 p.m.
...
2. Should I leave the V20 in? I've heard it has
compatibility issues with some programs, but I'm not solid on
my information.
There may be some exceptions, but I never had any problems. It was supposed
to be somewhat faster so I suppose some programs might have shown timing
dependency problems.
Gil
Regards,
Julian
8:19 p.m.
On 8/29/05, Wolfe, Julian <ISC277 at clcillinois.edu> wrote:
Hi everyone!
I have an old Portable PC that I put a 2MB memory card in, along with an EGA
card, sound card, and some other stuff. I'm doing my best to max it out.
Anyway, I'm having some trouble with hard disks. I have two hard disk
controllers: a Seagate ST02 SCSI/Floppy controller, and a Juko Labs D16-X
ST02 uses NCR 53C90A I think. I think maybe the seagate bios only
support 6 byte commands, thus limit the disk size to 1GB. It is not
53C90A's fault. It is not easy to find a bootable 8 bit SCSI card. I
once had two. one was HB_A8 card, the other I forgot the brand. I
could not recall how big the disk sizes they supported.
IDE controller. Now both of these cards work okay,
except they recognize
some strange sizes for the disks. The only disk that seems to show up
correctly is a Quantum LP105S...the others I tried, all bigger than a gig,
are either not recognized, or recognized with the wrong size. This is also
the case with the IDE controller - everything is recognized at 10MB. I
purchased an LBA PRO card for my machine hoping to overcome the large disk
size problem, but all it does is freeze the machine...however, if I remove
the 8088 and replace it with a NEC V20, I get the banner for the hard disk
drive card, and THEN the machine freezes.
So my questions are:
1. Does anyone know a good solution for putting a large drive in an XT,
while still leaving it an XT?
2. Should I leave the V20 in? I've heard it has compatibility issues with
some programs, but I'm not solid on my information.
Regards,
Julian
8:35 p.m.
Wolfe, Julian wrote:
1. Does anyone know a good solution for putting a
large drive in an XT,
while still leaving it an XT?
IDE with "540MB" (actual capacity is less) drives or less, if you can find an
IDE card that works. I have two (different brands) but sadly I haven't found
time to try them yet in my model 5150. Only other solution is SCSI, something
I have had extremely unlucky progress with (boards with BIOSes won't POST;
boards that need drivers don't have the damn drivers bundled with the board;
etc.) However, I believe my experience with 8-bit SCSI on XT is uncommon
compared with the other gentlemen here.
2. Should I leave the V20 in? I've heard it has
compatibility issues with
some programs, but I'm not solid on my information.
The V20 can enable some ill-behaved programs to work as it implements the "SHL
register,immediate" 80186 opcode, and this opcode is sometimes the *only* used
opcode used in "286-only" programs. I was able to run programs claiming they
needed a 286 on my AT&T PC 6300 (Olivetti M24 8086 clone) after I upgraded it
to an NEC V30.
HOWEVER, the V20 and V30 expand the prefetch queue from 4 bytes to 6 bytes (the
source of their speedup) and this screws with timing-sensitive programs such as
games, copy-protected diskette copiers, and turnkey stuff like robot
controllers, etc. from the early 1980s.
I'm going to go out on a limb and assume that you're expanding your convertable
so that it can play most IBM PC games from the 1980s. :-) Based on my
experience in that context, the V20 will cause the following behavior compared
to a factory original 8088:
- 88% of games will run just fine, unaffected by the V20
- 5% of games will run smoother/better due to the small speedup of the V20
- 5% of games will run too fast to be enjoyable
- 2% of games will not run at all
Games are a good example to flush out this kind of behavior because they were
usually programmed as close to the hardware as possible to achieve the best
performance; also, many copy-protection schemes are timing-based and may fail
if the CPU speed is not what is expected.
If I have incorrectly assumed your intentions, please let me know as I'm dying
with curiousity :-)
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
30 Aug
30 Aug
12:23 a.m.
I'm maxing out the machine for the sake of maxing out the machine.
The portable is a semi-rare beast; it's an XT in a wierd portable
case. I actually bought it as a machine to diagnose car problems
with via the DIACOM software, but I got rid of the car I was using it
on! now it's an experimentation box. I already did the 640K mod to
the mainboard, bought a 2MB EMS card, I have a 1.44MB floppy
controller that works as long as only the MFM disk is in the
system...it won't work with the IDE controller I have, OR the Seagate
ST02.
What do I have for software on it that I actually USE?
PC-DOS 2000
Wordperfect 5.1
Lotus 1-2-3 2.1
Quicken 6.0 for DOS
Windows 3.0
IBM PC Storyboard
All the Watcom TCP/IP tools I can find
Overland Data Tools for DOS (for backing the thing up to 9 track
tape, HAHA)
Oh...and I play a few games on it...yes. ;)
I do testing for the MS-DOS Turbo C port of Sarien with it, to make
sure it runs on 8088/8086.
So to say the machine is "lightly used" would be totally wrong. I
beat the silicon out of it.
On Aug 29, 2005, at 10:35 PM, Jim Leonard wrote:
Wolfe, Julian wrote:
1. Does anyone know a good solution for putting a
large drive in
an XT,
while still leaving it an XT?
IDE with "540MB" (actual capacity is less) drives or less, if you
can find an IDE card that works. I have two (different brands) but
sadly I haven't found time to try them yet in my model 5150. Only
other solution is SCSI, something I have had extremely unlucky
progress with (boards with BIOSes won't POST; boards that need
drivers don't have the damn drivers bundled with the board; etc.)
However, I believe my experience with 8-bit SCSI on XT is uncommon
compared with the other gentlemen here.
2. Should I leave the V20 in? I've heard it
has compatibility
issues with
some programs, but I'm not solid on my information.
The V20 can enable some ill-behaved programs to work as it
implements the "SHL register,immediate" 80186 opcode, and this
opcode is sometimes the *only* used opcode used in "286-only"
programs. I was able to run programs claiming they needed a 286 on
my AT&T PC 6300 (Olivetti M24 8086 clone) after I upgraded it to an
NEC V30.
HOWEVER, the V20 and V30 expand the prefetch queue from 4 bytes to
6 bytes (the source of their speedup) and this screws with timing-
sensitive programs such as games, copy-protected diskette copiers,
and turnkey stuff like robot controllers, etc. from the early 1980s.
I'm going to go out on a limb and assume that you're expanding your
convertable so that it can play most IBM PC games from the
1980s. :-) Based on my experience in that context, the V20 will
cause the following behavior compared to a factory original 8088:
- 88% of games will run just fine, unaffected by the V20
- 5% of games will run smoother/better due to the small speedup of
the V20
- 5% of games will run too fast to be enjoyable
- 2% of games will not run at all
Games are a good example to flush out this kind of behavior because
they were usually programmed as close to the hardware as possible
to achieve the best performance; also, many copy-protection schemes
are timing-based and may fail if the CPU speed is not what is
expected.
If I have incorrectly assumed your intentions, please let me know
as I'm dying with curiousity :-)
--
Jim Leonard (trixter at oldskool.org) http://
www.oldskool.org/
Want to help an ambitious games project? http://
www.mobygames.com/
Or check out some trippy MindCandy at http://
www.mindcandydvd.com/
4:02 a.m.
At 09:28 PM 8/29/05 -0500, you wrote:
Hi everyone!
I have an old Portable PC that I put a 2MB memory card in, along with an EGA
card, sound card, and some other stuff. I'm doing my best to max it out.
Anyway, I'm having some trouble with hard disks. I have two hard disk
controllers: a Seagate ST02 SCSI/Floppy controller, and a Juko Labs D16-X
IDE controller. Now both of these cards work okay, except they recognize
some strange sizes for the disks. The only disk that seems to show up
correctly is a Quantum LP105S...the others I tried, all bigger than a gig,
are either not recognized, or recognized with the wrong size. This is also
the case with the IDE controller - everything is recognized at 10MB. I
purchased an LBA PRO card for my machine hoping to overcome the large disk
size problem, but all it does is freeze the machine...however, if I remove
the 8088 and replace it with a NEC V20, I get the banner for the hard disk
drive card, and THEN the machine freezes.
So my questions are:
1. Does anyone know a good solution for putting a large drive in an XT,
while still leaving it an XT?
2. Should I leave the V20 in? I've heard it has compatibility issues with
some programs, but I'm not solid on my information.
I used a V20 in my old Sanyo and never had a compatiblity problem except
that certain games ran faster and were difficult to control. FWIW.
Joe
Joe
Regards,
Julian
7053
days inactive
7055
days old
10 comments
9 participants
participants (9)
-
ard＠p850ug1.demon.co.uk -
fireflyst＠earthlink.net -
gilcarrick＠comcast.net -
ISC277＠CLCILLINOIS.EDU -
jhoger＠pobox.com -
jpero＠sympatico.ca -
rigdonj＠cfl.rr.com -
trixter＠oldskool.org -
vax9000＠gmail.com