Just added to collection - 750Cs

[fultontech]

Just running diagnostics now.

20MB RAM
340MB HDD
2.88MB FDD
Dock I with CD-ROM

Looks like it got dropped about 1996 and put back in the bag since it wouldn't turn on. The battery contacts may be the only thing damaged and powers up just fine once the battery is removed. Update: It was just the battery.

The original install still there.
PC DOS 6.1
750Cs demo
Prodigy

I know, I know pictures. I'll make some as soon as I can.

[TrowaBarton]

I bought a 750Cs on ebay recently, haven't gotten to tinker with it much yet, wrapping up 701 stuff.
340MB drive
Bought a 32MB ram card for it.


Mine does the same thing with the battery pack installed, as soon as its connected the machine will turn off. I checked the HMM and tested, the charging system in the laptop still works, the battery's voltage is woefully low as to be expected. Has anyone dissected these to attempt rebuilding? I've rebuilt a 701 battery pack so if people are interested I'll cut this one open so we can all take a peek inside, the contacts look clean from the outside, who knows what kind of corrosion may have taken place within.

[Norway Pad]

I dissected a 360 battery pack, which from the looks of it is identical to the 750 battery pack. No leaks inside mine, so I looked into rebuilding it with standard cells. But the cells I found online would have totaled at more than $100, so I chose to put it off, as I basically boot up these old guys twice a year.

I can post pictures of my 360 battery, if you don't already cut yours open, Trowa Barton. It was actually a pain to open it, as the plastic case is pretty thick and the two parts were well joined.

[TrowaBarton]

Yeah pictures would be nice, this battery pack feels super hefty and well encased. Getting a good look at the cells inside would help decide whether or not to pursue repairs.

[fultontech]

The prior owner already opened the included battery. Let me figure out where I'm putting photos.

[fultontech]

I dissected a 360 battery pack, which from the looks of it is identical to the 750 battery pack.

The 750 has a smart battery that can be used in the 360, but the original 630 battery doesn't have the circuitry and might not work in the 750.

[TrowaBarton]

The 750 has a smart battery that can be used in the 360, but the original 630 battery doesn't have the circuitry and might not work in the 750.

While probably true, I'm more interested in seeing the cell arrangement, if the chips aren't corroded to death when I pry mine open they should hopefully work with new cells attached.

[Norway Pad]

I took some pictures today, so I might as well share them. First one is the 360 battery that I cut open. No circuitry at all, except from what seems to be a temperature sensor that is connected directly to the contact points of the battery. What I believe is the 750 battery is the black one: https://lh4.googleusercontent.com/-cgs0 ... 320_165726

The 750 has a smart battery that can be used in the 360, but the original 360 battery doesn't have the circuitry and might not work in the 750.

That might be the case, yes. When I took the picture above, I noticed that there is a red sliding switch on the top of (what I assume is) the 750 battery. Unfortunately the label is torn off, so I don't know what the switch is described as. But unless it's just a pure indicator for the user, it might indicate a circuit inside.

When we bring up the subject legacy batteries; do the two of you by any chance recognize the other batteries I have? All these came along with the 750 when I bought it. One of them is similar to the 360 battery, but no idea what the two other battery types belong to. They don't fit in any of the Thinkpads in my signature. 755? 760?

The top faces with the labels:https://lh3.googleusercontent.com/-kjrX ... 320_165707

The connectors:https://lh5.googleusercontent.com/-sJ_X ... 320_165947

[fultontech]

I'm at a client site but I wanted to chime in here before to much work got done with the reinvention of the wheel.

Without getting in to the holy war over should one or should one not mess with the battery due to fire, explosion, leaking, and hair loss - lets quickly go over how the ThinkPad batteries we are playing with here are constructed. The switch on the 750 battery is a storage switch (i.e., if you're not using/charging the battery for a month or more), to break the circuit to the little processor so the charge to the battery doesn't over draw.
The processor (smart battery) had a little program in it's memory that provided more detail to the power management software on the computer that in turn showed percentages and runtime left. The dumb batteries just show high/low. If you have the user's guides for the 360/750 it shows the difference between the display.
When the battery overdrew (which the smart battery was supposed to avoid) and/or went flat - there was no more current available to hold the little program in memory. No more smart battery. So now it's just a dumb battery, right? Well yes and no.
When these older batteries get that low there is a safety that stops them from charging or discharging - smart or dumb. Even if you replace the cells, if the circuit was tripped, it won't supply power. There are methods to "jumpstart" a tripped battery shown on the Internet, but the smart battery (750) will never be the same as it was back in 1993 direct from IBM.
Many of the referb units from 3rd parties sold on ebay back about 2000 were just jumpstarted batteries with the original cells.

[Norway Pad]

Ok, thanks. The part about the 750 battery and the purpose of the switch was useful to know.

For the rebuilding part, I actually wouldn't bother with a "smart" battery where there are electronics that can theoretically shut down the battery beyond my control. So that's why I made plans for rebuilding the dumb 360 battery. Unfortunately the cells needed were too expensive for my liking, particularly for a laptop that's never used. However I still plan to rebuild a 701C battery, as I can use regular AA cells for it, and the laptop is used from time to time.

[fultontech]

All the batteries will have that safety circuit, laptop, camcorder. You might be able to use what you already have. The jumpstart process (as seen on the internet) just overpowers the safety circuit for a second. As far as the 750 battery with the torn tag; there were different models for Europe/Asia. I've ended up with one that was to be sold/used Norway somehow.
The ThinkPad 8xx had/have a similar switch on their batteries as well.

[Norway Pad]

Ok, good to know. I'll leave the rebuilding of a 750 battery to Trowa Barton. I'll stick with my 360 and 701C batteries with no circuits whatsoever.

Funny that you ended up with a 'Norwegian' 750 battery. That's 100% identical to mine then, as this pile of batteries and the 750C are among the very few Thinkpads/parts I have ever found here in Norway.

[TrowaBarton]

Ha... thanks for the vote of confidence...


I have recently jump started some Li-Poly ultrabay batteries of the T43/R52 era, I was mildly terrified but they never got hot or anything. Their battery life was quite poor, but they did essentially work afterwards.

The fact that there are SIXTEEN?!!!!!! cells inside this battery, without measuring I would guess they are 4/5AA sized cells, I've used them before when rebuilding a Sega Nomad battery pack.

I'm not entirely sure if fultontech's statements on safety circuits apply to nimh, they are most certainly correct for lithium based batteries where explosion/fire is a real danger. While the HMM does mention the "microprocessor" it doesn't say anything about its purpose.

I'll certainly crack it open in the future when I have the time, it doesn't do any good dead.

[Norway Pad]

There are indeed 16 cells in there, and I the ones I found back then, with solder tabs, were $5-6 a piece. There might be cheaper ones to find, so feel free to share if you find some more reasonable cells for this project.

Good luck!

[fultontech]

I still love that he made a page for this very subject.

http://www.conradshome.com/thinkpad/701/battery/

[Norway Pad]

Great site! That very page was my kick to go ahead and plan for that. Luckily my 701C batteries aren't corroded, so a better starting point than his. Got the AA NiMH rechargeables not that long ago, but too little free time to actually do it..

[fultontech]

I picked up a second one for parts, it's a about a year newer so the CPU is not the same. The UPS driver dropped the box in the street right in front of me. It may have been working before it was shipped, but it goes straight into sleep mode upon boot up now. The FDD and HDD check out ok, Memory is fine. It's acting like I have the keyboard open upon power up.
Sigh. Well at least I got the PCMCIA cover

[TrowaBarton]

What kind of CPU is in it? They made 750Cs with cpus other than 33Mhz?

[Norway Pad]

The various 750 models (750, 750C, 750Cs) were offered from September 1993 to September 1994, but according to my sources only with the 486SL 33MHz CPU.

Bummer about having it dropped, and might broken, though.

[fultontech]

The various 750 models (750, 750C, 750Cs) were offered from September 1993 to September 1994, but according to my sources only with the 486SL 33MHz CPU.

Bummer about having it dropped, and might broken, though.

Sorry, sorry.

dropped one 9545-2Y6

9545-208 is fine

the screen may be what was different

[fultontech]

While the HMM does mention the "microprocessor" it doesn't say anything about its purpose.

I believe it's explained in the User's Guide. I have the 360 doc's. Let me look when I get home. It really looks like I have a lot of pictures I need to catch up on.

[fultontech]

Just to update. I am still trying to get the preload off this thing before anything else.
I got a unlicensed/unused copy of LapLink V (1992) with working/readable 720KB floppy and cables.

My intent was to copy the data to the T30 and use the USB 1.0 to move elsewhere.

Silly me. No DOS mode in WinXP. What? Just make a boot disk? Ok, couple of different ways to actually do that in XP, but how do you load the NTFS drive C partition easily? Then just use Hiren's Boot CD and the DOS utilities. OK. So that worked and I was able to run LL5 and connect the two systems. However, every attempt at actually moving data locked up the T30 after a few bytes.

Ok, it must be something in the Hiren's Boot CD DOS environment. So I wipe the T30 (since it was just the base factory install anyway) and pull out the Win98SE CD.

I forgot several things about installing a single thread OS and various hardware issues. You just don't run into the same problems in a virtual machine environment now days.

Hard disk and memory size limitations in Win98 and earlier come into play on the T30. I noticed odd behavior using fdisk on the 60GB drive, but didn't think about it. I enabled large disk support and use the whole disk. Then I started the format to the drive.
12 hours later... Error formatting drive. (It still didn't dawn on me what was going on).

Fdisk and format from the command line instead of the Win98 setup.

12 hours later. Fail. Hmmmmm maybe it's the disk... no... I just tested it a few days before. Hey, I wonder if it's that size issue like back in the old days.....

fdisk - No LBA support this time. It made a 2GB partition.
Format - no error.
Win98 install - no error.

I feel very silly. I should have remembered that.

[TrowaBarton]

I haven't popped open the drive case yet, I imagine its still 44 pin IDE inside correct? I popped my 701c drive into a USB enclosure and made a ghost image of it. I did have to make a small jumper wire to go from the 5V to ground right under it to get the drive to actually spin up, but otherwise it worked fine.

Or if you have the ultrabay hard drive adapter you could try seeing if the drive will get recognized by your T30.

[theterminator93]

I find most success in making images old disks using a USB-IDE adapter; I've done it most recently with my 701c and TransNote. I've got a few different imaging tools and all seem to work well either from a booted environment or Windows (Acronis boot disk, Windows PE with Ghost 2005, IsoBuster Pro)...

[fultontech]

I'm trying to do it with the least risk physically to the unit. It's one of the first production runs. After I get the data off the drive, I'll feel better about taking thing apart. There are a few parts of the case with damage that I want to replace and so forth.

[theterminator93]

Definitely understand that.

I couldn't quite understand from the post from earlier, are you having more luck getting data to copy off the drive using LapLink V with 98 as the host OS on your T30? I wonder if there could be any success with a DOS boot disk with Ghost alongside a DOS-supported/config.sys enabled PCMCIA NIC to copy an image over LAN...

[fultontech]

I had to put it away until next weekend.

Now that I've got Win98 on the T30 (and the USB mass storage driver installed) I'll try that before anything more drastic.

The end goal of course is to cause myself endless frustration by installing AIX 1.3 via floppy.

[TrowaBarton]

I wonder if there could be any success with a DOS boot disk with Ghost alongside a DOS-supported/config.sys enabled PCMCIA NIC to copy an image over LAN...

This is essentially what I did the first time I backed up a 701 factory image. I don't recommend trying to run ghost on a 486 though... unless you want it to run for many hours. I put the drive into an R52 and booted that from a ghost flash drive instead.

Then later on I was able to get the drive recognized in my IDE/Sata to USB dock and things were much simpler to do.

[Norway Pad]

I made a Clonezilla image of one of my 360CS systems just by removing the drive from its enclosure and connecting it to a IDE->USB adapter connected to my T60. Clonezilla recognized the drive, and created an image file like it should. Later I realized that I won't know for sure if this works before I try to put the image back on a drive and see if the machine actually boots from it. I have a couple of those old small drives, so I will try that once. Do any of you guys have experience with restoring an image like this through a IDE->USB adapter?

If it works, I have a factory IBM Win3.1 install on my 750C that I would like to preserve for the future.

[theterminator93]

Usually when I get an external adapter involved it's for making images - I've only restored an image to a USB connected HDD once. I did that with a failing hard disk image file created via IsoBuster (this was on my TransNote), then restored it to a new HDD with https://launchpad.net/win32-image-writer. Worked fine.

I usually create my images with an Acronis boot disk and save them in their compressed .tib format. When I need to restore, it's to the internal disk. However, there shouldn't be any issues restoring to any physically connected disk - regardless of the interface - with that software.