Thinkpad R40 woes \ VOGONS

Thinkpad R40 woes

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First post, by trozx

Posted on 2025-06-20, 16:17

trozx Offline

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Rank: Newbie
Posts: 18
Joined: 2021-10-08, 20:51

Greetings,

The aforementioned machine is pretty neat, but I'm having a few issues I hope someone has experience with.

1) The dang IDE controller appears to be stuck in PIO mode - across multiple OSes. Win98 and Linux. I checked the BIOS for any related settings. Nada. In Win98 the DMA box is checked under the HDD in dev manager, but any serious HDD activity (lots of tiny/random reads) slows the machine to an absolute crawl. Under Linux, same story. Updated drivers. Updated BIOS. No change. Next step is to swap out the HDD. Maybe the drive controller is faulty and forcing the system to PIO? Suggestions?

2) The system is booting from BIOS with 638KB of conv. memory. By the time you get to DOS it has dropped to 636KB. This reminds of boot sector viruses from back in the day. The autoexec.bat and config.sys are empty. What the heck?! Is this normal for a R40? I dont think so. I'll run Memtest86, but I'm not expecting any surprises.

The attachment 638KB.jpg is no longer available

Bad hardware? Bad caps? Viruses? Oh my...

Maybe more trouble than it's worth.

Reply 1 of 3, by onethirdxcubed

Posted on 2025-06-20, 16:35

onethirdxcubed Offline

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Joined: 2025-05-30, 00:19

I'm pretty sure that the 2k of missing memory is from ACPI tables loaded by the BIOS.

Reply 2 of 3, by Masaw

Posted on 2025-06-23, 03:34

Masaw Offline

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Joined: 2022-10-22, 04:44

could be a symptom of a boot sector virus infection allocating a portion of RAM during its resident process.
you can try my portable antivirus software, it can detect and remove a handful of common boot sector viruses.
just run it under dos not dos box under windows to be effective

Last edited by Masaw on 2025-06-26, 00:14. Edited 1 time in total.

VCheck+ Portable Antivirus for DOS
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======

Reply 3 of 3, by trozx

Posted on 2025-06-25, 16:36

trozx Offline

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Rank: Newbie
Posts: 18
Joined: 2021-10-08, 20:51

Masaw wrote on 2025-06-23, 03:34:

could be a symptom of a boot sector virus infection allocating a portion of RAM duing it's resident process.
you can try my portable antivirus software, it can detect and remove a handful of common boot sector viruses.
just run it under dos not dos box under windows to be effective

Thanks for that - I checked, nothing detected.

I'm thinking onethirdxcubed might be right about the ACPI tables. I found a POST photo from some other R40 owner, and the conv. RAM is also 638KB. This trips up some software that checks for memory managers that shouldn't be present (during it's operation), and aren't running! I wonder why IBM decided to eat up previous conv. memory for something like ACPI? Alas, the computer was designed to run WindowsXP, so I guess DOS was becoming a thing of the past.

As a side note, I remember some older HP desktop computers used a common Abit or Asus motherboard vs developing their own, and you could flash the OEMs BIOS to the board and do away with HP's crap. Of course laptops are a different game and I doubt that is possible here. One other thing were BIOS editors from back in the day. You could unlock the *hidden* items OEMs didn't want you tinkering with. Other manufacturers had a keyboard combo that would unlock hidden items, but I don't know of any for IBM Thinkpads.

As an update to my first issue: Replacing the original HDD seemed to fix my PIO vs DMA issue. Performance is greatly improved. I can work with this.

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