IBM Thinkpad T43

Specs

• Intel Pentium-M 1.86GHz
• ATI X300 GPU with 64MB
• 15“ 1024×768 screen
• 2x DDR2-SODIMM slots (this came fitted with 2x 512MB DDR2-400 modules, 2GB is maximum)
• 2.5” PATA/IDE drive
• 2x USB 2
• vga OUT
• Parallel
• PS2 keyboard/mouse
• 10/100/1000 Ethernet
• Modem
• 3.5mm headphone out
• 3.5mm microphone in
• 1x Expresscard slot
• 1x Cardbus slot
• CDRW/DVD drive in Ultrabay module

The T43 is available in a variety of screen sizes and resolutions. Typically the inverter, cable and LCD panel all need to be from the same size/resolution series:

• Ultrabay Slim SATA HDD Adapter: adds a 2.5” SATA bay (includes PATA to SATA chip). Part numbers 40Y8725, 45J7901, 45J7902, 26R9246, 26R9247
• Ultrabay Slim PATA HDD Adapter: adds a 2.5“ PATA/IDE bay. Part numbers 62P4554, 41U3148, 41N5661, 41N5660

• 6 Cell, 4.8Ah: 92P1087, 92P1089, 92P1091
• 9 Cell, 7.2Ah: 92P1077, 92P1073, 92P1069

Good Points

• Relatively good condition - limited amount of wear / scratches to case
• Nothing smashed or cracked

Bad Points

• Stuck GPU/CPU fan - Partial fix, below Replacement fan unit fitted
• Discharged BIOS battery - 20-30 minutes worth, which is okay for a 20 year old laptop
• Missing hard drive / PATA only drives - Fitted a WDC WD120BEVE
• Backlight/inverter aged - Replaced screen with new-old-stock

The proper way to repair the noisy fan would be to replace it with a new part. In this case I didn't know if the machine was in a fully working state so I went the hack route…

First I soaked the fan bearings in isopropyl alcohol to clean out any residual oil/grease - the fan wouldn't turn when the machine first arrived. After getting the fan spinning freely again by hand I then drilled several small holes through the plastic central hub and carefully dripped in some lubricating oil. This clearly isn't the best way to solve the problem, and the sleeve bearing really isn't design to be serviced, however it did work, and the fan spins freely, though with a little vibration from the god-knows-how-long-it-has-been-seized bearings, and is somewhat less-than-annoying in terms of sound level.

If the machine all checks out, then it may be worth replacing the fan with a new part.

[Update September 2025] After using the laptop on and off for games for a month or so it seems reliable and does what I wanted, so I found and ordered a new-old-stock fan unit from Aliexpress. It was less than £5 including shipping and only needed the old fan to be prised off the heatsink. Much quieter and no vibration any more. Perfect.

The original panel had a distinct red tint on first start, for maybe 15-20 seconds, it was also fairly dim - even at maximum brightness. All symptoms that point to the backlight / CCFL failing, or not having much life left:

Replaced the old screen and backlight with a new-old-stock panel of the same type and it looks as good as new:

• IBM T43 Hardware Manual
• BIOS - Last official BIOS v1.29
• Platform Controller s/w - Last official Platform Controller software v1.06
• DOS PS2 utilities - DOS PS2 configuration utility for T4x series (LCD control, speed, brightness, fan control etc)
• Broadcom ODI packet drivers for DOS - compatible with MTCP and other DOS packet-driver utilities
• Thinkpad PCMCIA / Card Services - compatible with the T43

In addition, there is a patched version of BIOS v1.29 which codes out the whitelist of IBM-approved hard disks, and gets rid of the annoying “Press F1 / ESC to continue” message and double-beeps that occur on every reboot if you have a non-IBM approved hard drive

• BIOS - Patched BIOS v1.29

If BIOS and/or platform controller software is not up to date, the order to install them is BIOS then Platform Controller.

• Use VSBHDA - audio support is detected as ICH6. The volume controls (up, down, mute) above the keyboard work regardless of software, so this is useful for games in DOS.

• Use Cutemouse - detects Trackpoint nub and buttons (works fine). The lower Touchpad and buttons do not appear to respond in DOS.

• No native DOS packet drivers, but you can use the B57.COM ODI driver and then the ODIPKT shim to make the ethernet controller work with DOS packet-driver aware applications (e.g. MTCP)

The ODI drivers should be loaded as follows:

LSL.COM
B57.COM
ODIPKT.COM

You will need to configure NET.CFG as below:

Link Driver B57
        envelope type ETHERNET_II

• Disable USB ROM Floppy/CDROM boot support to claim back a portion of upper memory.
• Disable Network PXE ROM support to claim back a portion of upper memory.

With both ROM extensions above disabled, use D000 as the EMS page frame in EMM386/JEMMEX.

You can seem to use B000-B7FF with JEMMEX for a small amount of UMB memory - though be aware this disables support for really old monochrome DOS games. There are no other regions available.

The entry to config.sys looks like this:

device=c:\drivers\jemmex\jemmex.exe frame=d000 i=b000-b7ff
dos=high,umb
fileshigh=20
buffershigh=10

The T43 has a PCMCIA/Cardbus (up to Type-II size) socket (just one, the upper socket is a variant of PCI-Express and not compatible with PCMCIA/Cardbus cards). IBM/Lenovo provide drivers to enable this in DOS, but they have a major limitation - it only appears to enable the PC Card sockets in PCMCIA mode (i.e. 16bit) and not in Cardbus (i.e. 32bit PCI).

This means that if you have Cardbus cards and DOS drivers for them, then they will not work.

Normal PCMCIA cards and DOS drivers do appear to work (verified with DLink DFE670 10/100 NIC and Roland SCP-55 MIDI card).

Under other operating systems with proper Cardbus drivers (Win9x, 2000, XP, etc) or in Linux, the Cardbus functionality seems to work perfectly.

If using PCMCIA services in DOS, you must exclude the D000-D7FF range from EMM386, JEMM or any other memory manager.

1. Ran in incompatible video mode

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