IBM ThinkPad 755CSE

Another ThinkPad from IBM, good quality laptop with color LCD and 486DX4/100MHz processor. 10.4" passive LCD allowed to display colors in 640x480 resolution. There was 8MB of RAM onboard, expandable. Hard disk was 350, 540 or 810MB in different variants. This notebook also has IBM MWave sound device and modem, PCMCIA and infrared.


Manufacturer IBM

Origin USA
Year of unit 1994?
Year of introduction 1994?
Type Laptop, PC
CPU 80486DX4, 100MHz
RAM 24MB (8MB On board, expandable by cards)
Floppy Disk 3.5", 1.44MB
Hard Disk Originally 810MB
Other media None
Graphics and display: VGA, color passive LCD
Sound: PC Speaker, embedded speaker (MWave sound card)
Keyboard and pointing device: Compact keyboard with most function keys.

TrackPoint pointing device

OS: MS-DOS, Windows 3.x, Windows 9x, maybe NT 4.
If you have >=16MB RAM I recommend Win95.

Power supply:


Male proprietary connector. Single goldpin connectors fit well.

1 - S???
2 - +20V DC
3 - GND
4 - G???
You can leave 1 and 4 unconnected

I/O:  - Serial port
 - Parallel port
 - DB9 video out
 - Dock connector
 - 2 PCMCIA slots
 - PS/2
 - Speakers and mic connector
 - Phone line for modem
 
 
 
 
 
 
Possible upgrades: Memory, PCMCIA, dock
Additional peripherals:  Port replicator

It's a ThinkPad. ThinkPads have GUI BIOS setup, as a system of mouse-driven icons, they usually have some diagnostics onboard. Battery is usually CR2032 or similar in heat shrink sleeve with cables. ThinkPads are not laptops with problems.

About flashing BIOS, you must have a 100% charged battery, what is not possible if you have old one. There's a risky method to cheat battery controller to think battery is fully charged.

Interesting fact: ThinkPads 755 were used during space missions: information was present in IBM web site (archived)

Drivers - As IBM support does not cover old ThinkPads anymore and existing pages redirects to random sites with partial driver patches, I have to put files mirrored from ?now-defunct? IBM's PCBBS here. These files are taken from PCBBS mirrror taken in 2000.

Installing OS/2 Warp in 755
Upgrading to Windows 95
ThinkPad 755 tips
ThinkPad 755CX User's guide
Hardware Manual (external link)
IBM BIOS update 1.44 [README] [WARNING! Flashing may damage your computer!]
Utility disks
Diagnostic disk [README]
[DOS/W3X/OS2] PCMCIA disk [README]
[WINNT] Power management driver [README]
[WINNT] MWave patch for NT4 [README]
[WINNT] ThinkPad Features [README]
[WINNT] MWave with 336.K support: Disk1 Disk2
[WINNT] Infrared drivers [README]
[WIN98] MWave APM patch for Win98 [README]
[WIN] IR/Parallel/Serial transfer tool Disk1 Disk2
[WIN95, 98]MWave disconnection patch [Readme]
[WIN3x,9x,NT] MWave MIDI driver PART1, PART2, PART3, PART4 [samples and such stuff]
[WIN9x] MWave sound drivers: DISK1, DISK2, DISK3, README
[WIN95] MWave Windows QuickTime patch: Patch, README
[WIN9x] MWave APM patch for Windows - described in document LWIK-3ZASUM, fixes modem-related hangs
[WIN3x] MWave sound drivers: DISK1, DISK2, DISK3, README
[WIN3x] Video drivers [README] [WIN9x should have this driver]
[OS2] MWave MIDI driver  PART1, PART2, PART3
[OS2] MWave for OS/2: Disk1 Disk2
[OS2] MWave power management patch [README]
[OS2] MWave driver
[OS2] Dock drivers
[OS2] Video drivers [README]

To install sound you need MWave driver, to use MIDI you need separate driver which installs required samples.