IBM Thinkpad 240

• Intel Celeron 300 / 366 / 400MHz
• 64MB PC66 RAM onboard + 1 SODIMM socket (maximum of 192MB, or 230MB - with low density modules)
• Intel 440DX chipset
• NeoMagic 128XD 2MB video
• ESS Solo-1 sound
• 1x PCMCIA/Cardbus, 1x Parallel, 1x Serial, 1x IRDA, 1x USB, Line-in/Mic-in/Headphone out
• IBM Floppy connector
• Thinkpad 240 Hardware Reference Manual

Bought December 2024 with a cracked screen (which I knew about). Fortunately it is all working, as tested via the VGA output:

From the Thinkpad 240 Hardware Reference Manual:

There are two models of LCD panel used with the ThinkPad 240: LCD Type A and LCD Type B. Check the last five letters of the unit's serial number you are servicing to determine the model.

LCD Type A:
All ThinkPad 240 computers that have serial numbers whose last five alphanumeric characters are “00001” to “YZZZZ” are fitted with Type A panels.
Note: The number range is from 00001 to 99999, and the letter range is from AAAAA to YZZZZ.

LCD Type B:
All ThinkPad 240 computers that have serial numbers whose last five letters are “ZAAAA” to “ZZZZZ” are fitted with Type B panels.
The servicer need only check the fifth letter from the end.
If the fifth letter from the end is “0 — Y” (inclusive), then the LCD panel is Type A. If the fifth letter from the end is “Z”, then the LCD panel is Type B.

tldr; The screens are not swappable between Type A and Type B systems. It is the entire lid that is needed.

Swapping the entire 240X LCD assembly + cover does indeed work:

The ESS 1946 Solo-1E is a PCI sound chip that is Soundblaster Pro compatible. It is the last variation from ESS which contained their excellent ESFM technology for great-sounding FM music. Everything after this (both the ESS Allegro and ESS Maestro parts) sounds very poor in comparison.

This did take me a while to figure out, as I was trying to configure the ESS chip not to use the standard MPU401 port (since my Roland SCP-55 MIDI card also wanted it). I initially tried to disable the use of that port by the ESS drivers, but on doing so it would block access to the IBM keyboard! So, if you do have a Thinkpad 240 AND a Roland SCP-55, do not configure the ESS .ini file to disable MPU401, but instead move it to a different port (e.g. 0x300 instead of the standard 0x330>

You need the following three files to configure the ESS card fully:

• ESSOLO.SYS - loaded in config.sys
• ESSOLO.COM - loaded in autoexec.bat
• ESSOLO.INI - configuration file to set resources used

If the ESS card is configured correctly it should not leave behind a driver or TSR in memory (at least in real mode - YMMV with EMM386). Note that ESSOLO.INI is a binary file and needs to be edited with a hex editor

BYTE POSITION / MEANING
00: Sound Blaster IO (20 = 220, 40 = 240)
01: Sound Blaster IO (02 = 2xx (Cannot be changed))
02: DMA (00, 01, 03)
03: DMA (Not used and don't change, default 00)
04: FM Address (Default is 88 for 388h (Cannot be changed))
05: FM Address (Default is 03 for 388h (Cannot be changed))
06: IRQ (05, 07, 09, 10 (0A), 11-14 (0B-0E, serialized IRQ only))
07: IRQ (Not used and do not change, default 00)
08: Gameport Address (Default 01 for 201h (Cannot be changed)))
09: Gameport Address (Default 02 for 2xxh, change this to anything else to disable the Gameport)
0A: MPU401 Address (Default 30 for 330h, can be 00, 20, 30, 40)
0B: MPU401 Address (Default 03 for 3xxh, change this to anything else to disable MPU401)
0C: DDMA/TDMA/SB-Link (00 (DDMA), 01 (TDMA), 02 (SB-Link aka PC/PCI, set to this if using SB-Link connector on board))
0D: DDMA/TDMA/SB-Link (Not used and don't change, default 00)
0E: Not Used
0F: Not Used

Note: definition of ESSOLO.INI taken from: https://www.vogons.org/viewtopic.php?t=79832

It seems that on the Thinkpad 240 IBM wired up the ESS Solo-1E in PC/PCI mode, which gives it the highest level of compatibility possible.

Drivers and config for my ESS configuration (Address: 0x220, Interrupt: 5, DMA: 1, MPU: 0x300, Game Port: Disabled, DMA mode: PC/PCI), of course you should also set a BLASTER line in autoexec.bat (e.g. SET BLASTER=A220 D1 I5 T4):

• ess.zip

The PCMCIA chipset in the Thinkpad 240 is supported by Cardsoft drivers, and is available via

DEVICEHIGH=C:\DRIVERS\CARDSOFT\CARDXTND.SYS
DEVICEHIGH=C:\DRIVERS\CARDSOFT\SSCBTI.SYS /numada:1 /ada1skts:1
DEVICEHIGH=C:\DRIVERS\CARDSOFT\CS.SYS
DEVICEHIGH=C:\DRIVERS\CARDSOFT\CSALLOC.EXE

Here is a copy of the IBM-distributed Cardsoft drivers for the Thinkpad 240, extracted from the floppy-disk .exe they use, and compressed into a simple .zip:

• cardsoft.zip

Fastvid: FASTVID.EXE 011 2 F5000000

Benchmarks using 3DBench 1.0c and various slowdown techniques.

Using a combination of the SETMUL utility and the IBM PS2 Speed option:

1. Although reported as 61.7fps, this was in reality much, much slower. More likely single-digit fps speeds. Possible bug in the benchmark?
2. Reported as 35.3fps, but was actually much, much slower.
3. Although the lowest possible value set by the PS2 tool, 'FixedMin' seems to result in a processor clock equal to 'FixedMedium'.

Using a combination of the CPUSPD utility, along with SETMUL:

1. Using the PS2 Speed utility, to access states at T6 and below, you must have set PS2 SPEED FIXEDMEDIUM or less. If the PS2 tool has been set to FIXEDMAX the new state will not stick.

This gives the following approximate speed levels: