The IBM Thinkpad 700c is an iconic machine. We've covered the journey to this machine in detail elsewhere but in brief, IBM had a long and chequered history developing portable machines, and were always behind the times, selling 'me too' machines which had no unique standout features. As IBM USA continued to stumble, IBM Japan had successfully developed a series of notebook machines along with some flourishing unique features such as a stunning 10.4" TFT display which would fit into a notebook.
After the PS/2 note N51 adopted the international MCA architecture, IBM managed to pull in all it's resources and release a truly stunning notebook - the PS/55 C52 was re-branded with the previously failed-tablet's Thinkpad brand name and sported a distinctive red dot to replace a cumbersome mouse.
Also as we have said before, aside from the Trackpoint II, none of the features were strictly brand new, but they had been miniturised to the point everything could fit into a briefcase, combined and optimised for what mobile users needed.
Around this time, there were other Thinkpads - there was a monochrome STN Thinkpad 700, along with the Zenith-manufactured 300, embers of the Japanese-influences notes and seperate IBM design were seen in the note 425 and similar Thinkpad 350, but they were all essentially pretenders to the Thinkpad brand, which went on to evolve into many more successful black machines with a red dot.
After 30 years, time has not been kind to the 700c. There are four main factors to be careful about:
1) There is a small barrel 'bridge' battery inside, meant to maintain power whilst the main battery is swapped. This fails, leaks and corrodes.
2) The hinges become very stiff along with the black plastic becoming very brittle. This causes the bases of the hinges to snap and break.
3) Due to the unique MCA architecture in the 700c, you cannot use IDE devices so if the HDD fails, a replacement can be difficult.
4) If the CMOS battery has failed and the machine's settings have gone, it's likely you will need an IBM reference disk to restore the machine to working order.
Inside
I deconstructed a 700c, which wasn't too bad, but you have to keep tabs on exactly what screw came from where, and lay out what you remove in order so you can work back in reverse.
The only elecrolytic capacitors on the main system were 3 on the DC/DC board:
I've replaced 1 with a tantalum and the other two with new electrolytic. The only one which was leaking was a surface mount 47u one.
You need a reference disk to setup the system once you have replaced the CMOS clock battery.
Ok, we're in business. Set the clock, ran all the tests, the ESDI drive is fritzed..... ideas?!
I read that PS/2 ESDI isn't what everyone else called ESDI, so I guess until some really fanatatic nerdy person decides to either emulate or adapt specifically PS/2 ESDI, this machine is stuck with floppies!
The ESDI drives are made by IBM, of course, in a removable cradle that was only used in the 700 & 720. The N33sx, N51sx/slc, and CL57sx would probably have used the same basic ESDI drives, albeit permanently mounted rather than in removable cradles. Both the N51 and CL57 were also MicroChannel machines.
Remove Power-On Password (700, 700C)
To disable the ThinkPad 700, 700C power-on password, do the following:
1. Power-off the computer.
2. Remove the battery pack and the bottom cover.
3. Locate the password-override connector on the system board. (See 'System Board')
4. Install a jumper between the two pins at position 1.
5. Power-on the computer and wait until the POST ends.
Remove the jumper from the password-override connector when service is completed.
To get more 700/700C info, get this and also this.
Restoring One of Many
I've been trying to make a usable machine, which is difficult given that the hinges become so stiff, they snap the case.
3550 Expansion Unit
The IBM 3550 Expansion Unit is a docking station specifically designed for the IBM ThinkPad 700 and 700C laptops. It provides a way to connect SCSI devices, external displays (VGA), and other peripherals like keyboards and mice. The 3550 also includes serial and parallel connectors, offering a more desktop-like experience for these early ThinkPads.
Brief Description of Announcement, Charges, and Availability
The IBM 3550 Expansion Unit Model 001 provides desktop capability and expansion for the PS/2 (R) Model N51 SLC (TM) system. The unit accepts the N51 SLC using a simple docking procedure.
Releasing the system unit from the station is also easy.
Standard features include:
- Two full-size, 16-bit Micro Channel (R) slots
- One half-high bay supporting a 5.25-inch or 3.5-inch SCSI device
- Universal AC power supply
- SCSI on planar with an internal connector
- External ports
- SCSI
- Serial/Parallel
- Keyboard
- Pointing device
- VGA
- System unit battery charging capability
- Cover lock
- Key controlled power
- Security hook to attach cable or chain
- Display stand.
Planned Availability Date: November 27, 1992.
(R) Registered trademark of International Business Machines
Corporation.
(TM) Trademark of International Business Machines Corporation.
IN BRIEF . . .
o Provides expansion capability to the PS/2 Model N51 SLC (note, I think this is a mistype and should say C52/700/700C)
o Satisfies the mobile user's requirement for desktop capability in
a notebook system
o Protects users' investment in supported IBM peripherals
o Easy connection and removal of system unit
o Simplified cable management of connected peripheral equipment
o Optional Optical Drive Bezel Kit (#3780, 49G2670)
This feature is required when installing the internal
Rewritable Optical Drive (#0162, 6450162).