IBM PS/2 L40SX Laptop odd HD behavior.

[RWallmow]

So I was helping a friend with his L40SX laptop last night and we have both hit a wall on this super odd behavior. It will run and respond just fine when booted from floppy, however when booted from the HD (in this case a CF card, we tried multiple cards 128-512mb, all behave the same) as soon as the command line appears it will quit responding to keystrokes, and I assume it has hard locked since CTRL-ALT-DEL doesn't respond either. It had been working perfectly for quite some time, the HD is the only change, the old drive (which was already a modern replacement 20GB) failed, the only other PATA drive we had on hand was a 40GB (of questionable origin), but no amount of magic was able to get the L40 to even detect it. The CF cards will format and boot just fine and dandy, they process the config.sys and autoexec.bat just fine, but as soon as it hits the C:\> it goes non-responsive.

Our next test will be to try a different HD, I have some 10-20GB PATA drives at home, they were just not handy to us in our tests last night, and we really both want this thing running solid state HD so we would hopefully never have to go in and replace it again.


Also on a side note, if anyone's got any RAM that will work in this thing drop me a line ;-)

 

[Stone]

Try booting from a floppy and then turning full control over to the HD via environmental commands, e.g., SET, SHELL, etc. I'd guess it should work this way when booted from a floppy. I'd also suspect the reason it won't boot directly from the CF is a Boot Sector issue.

FWIW, I have found DOMs to be way less finicky/quirky than CF.

 

[mbbrutman]

What version of DOS did you install? What is in your CONFIG.SYS and AUTOEXEC.BAT? What is the partitioning setup?

If it made it all the way to the C prompt there probably is not a problem with the CF card, unless there is data corruption on it. To get to the C prompt the machine had to read the boot sector, execute it, find the active partition, load the hidden parts of DOS, install device drivers, and then manage to load COMMAND.COM. That's a lot of code.

When the L40SX was new hard drive capacities were very limited. To be on the safe side I partitioned my Disk-On-Module to use just 256MB of the 512MB available. You can easily go up to around 500MB without bumping into the classic BIOS CHS limits. (They start somewhere around 508MB.)

 

[RWallmow]

Try booting from a floppy and then turning full control over to the HD via environmental commands, e.g., SET, SHELL, etc. I'd guess it should work this way when booted from a floppy. I'd also suspect the reason it won't boot directly from the CF is a Boot Sector issue.

FWIW, I have found DOMs to be way less finicky/quirky than CF.

I did not try booting from disk and then turning control to HD, I will try that. From past experience with boot sector issues, I really don't think thats whats going on here, since it loads the boot sector, and even gets through processing config.sys and autoexec.bat, it only locks once its waiting on user input.

What version of DOS did you install? What is in your CONFIG.SYS and AUTOEXEC.BAT? What is the partitioning setup?

If it made it all the way to the C prompt there probably is not a problem with the CF card, unless there is data corruption on it. To get to the C prompt the machine had to read the boot sector, execute it, find the active partition, load the hidden parts of DOS, install device drivers, and then manage to load COMMAND.COM. That's a lot of code.

When the L40SX was new hard drive capacities were very limited. To be on the safe side I partitioned my Disk-On-Module to use just 256MB of the 512MB available. You can easily go up to around 500MB without bumping into the classic BIOS CHS limits. (They start somewhere around 508MB.)

We tried MS-DOS 5.0 and 6.22, both acted exactly the same. Config.sys had "device=himem.sys" and autoexec.bat just had "@echo off". I later edited autoexec to launch Windows 3.1 setup (stored on the CF card) and it launched it fine, however it would still not respond to any single keystroke, including CTR-ALT-DEL.

I know the L40sx has limited capacities, I don't think that's what we were hitting here, we tried some 128mb and 512mb CF cards, and each time it was able to "fdisk" and "format c: /s" more or less the whole capacity of them, but I suppose we could try making like a 20mb partition or something and see what it does with just that.

 

[mbbrutman]

I just powered up my L40SX to take a look at my CONFIG.SYS and AUTOEXEC.BAT.

I'm running PC DOS 6.3. I have HIMEM.SYS in m CONFIG.SYS file; nothing else is really interesting.

You might try adding STACKS=0,0 to your CONFIG.SYS file. MS DOS tries to install its own keyboard interrupt routines, which might not be compatible with the machine. By setting STACKS=0,0 you disable this feature of MS-DOS, leaving keyboard handling to the built-in BIOS routines. This trick is necessary on the PCjr when running later versions of DOS; MS-DOS might not know about the L40SX and causing a similar problem.