ThinkPad PC Card Boot?

I have several 1990s ThinkPad laptops which all have PCMCIA slots. Some have a built-in CD-ROM and no floppy drive, and no support for CD booting. It would be rather useful to boot them from PCMCIA ATA cards, and the BIOS looks like it supports that. But in most cases it just doesn’t work. Does anyone have relevant experience?

Here’s what I tried so far. I have a ThinkPad 560X which does boot from PCMCIA ATA devices. The BIOS basically treats the card as a regular hard disk. As long as the card has appropriate MBR, partition table, and bootable operating system, it works great. I successfully booted a Toshiba ATA flash card and an IBM 1GB Microdrive (in a CF to PC Card adapter).

The same cards refused to boot in a ThinkPad 760XL and 765D. The BIOS boot device configuration is the same as on the 560X but it just doesn’t work. Unfortunately there does not appear to be any way to diagnose what is going on.

I found this IBM document which suggests that booting from PCMCIA ATA cards should be generally supported by 300/500/600/700 series ThinkPads. But the document also contains this ominous sentence: “Actual customer use of ATA devices as boot drives has been extremely infrequent.”

The nice table on thinkwiki has far too many question marks to be very useful, unfortunately. The 76x ThinkPads aren’t even listed. The table does confirm that the 560X is known to work.

So what’s the deal? Is PCMCIA boot simply broken on many ThinkPads, even though the BIOS offers it as an option? Am I doing something wrong? Are there only specific BIOS revisions that work, and/or specific devices? The Internet is silent, at best showing questions but no answers.

For obvious reasons, if this worked it would be rather useful—a bootable PC Card in the 500 MB to 1 GB range can contain all the tools one needs, is very portable, and in the case of Microdrives can be easily hooked up to a modern system. Superior to floppy booting in every way, especially when many of these laptops don’t even have a floppy drive built in and need either an external one or a dock.

Update: ThinkPad 755C (486 DX4-75) with BIOS from 10/14/1994 can boot from some PCMCIA ATA devices. It boots from my Toshiba 640MB flash ATA PC Card and from two different CF cards (500MB and 1GB) in a CF to PCMCIA adapter. A 1GB IBM Microdrive (which worked in the 560X) did not work on the 755C.

A slightly older 6/14/1994 BIOS on a different 755C (DX2-50) works as well. Worth noting that on the 755C it is clearly visible that the PCMCIA activity indicator lights up several times during POST. Unfortunately the 76x/77x series laptops have no such indicator.

Late Update: ThinkPad 755CDV (Pentium 75) with BIOS from 01/18/1996 works even better. It can boot from the Toshiba PCMCIA ATA flash card, from a 1GB Microdrive, from the 500MB and 1GB CF cards, and from a Maxtor MXL-105 PCMCIA hard disk. In other words, every PCMCIA ATA device I tried worked.

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21 Responses to ThinkPad PC Card Boot?

  1. Trowa Barton says:

    I’ve been meaning to test out a WD SiliconDrive II 4GB CF card with my older ThinkPads, model SSD-C04G-4500. It was a free drive that was going to go in the trash.

    I’ve got a ThinkPad 701C, 750Cs, and a 560 (not x) that I’ve wanted to test it out in.

    I expect that I’m bound to get it stuck inside one of the machines if its even remotely insert-able in the first place.

    I’ll let you know what kind of reactions I get from them. I know that they are all essentially a generation or two before your test subjects.

  2. S Duggan says:

    It’s not just you. I tried this with my 600E, which supposedly also supports booting from PCMCIA if the Easy Setup screens are anything to go by. No go. Maybe booting from PCMCIA might be limited to supported IBM peripherals – Token Rings or external PCMCIA optical drives.

    The article you linked to talks about low level formatting using utilities provided, which I haven’t used as I only have old cards, which have been formatted umpteen times already, so this may be part of the reason – OSes might see and read the card due to drivers loaded but the more basic BIOS might not. There is also this “If all the above are done properly, and the card still does not work, it is either defective or incompatible.”
    which has echoes of the fussy nature of the 701 with regard to CF cards.

    Annoying, as it would be useful for a couple of my Thinkpads and this feature is something I use extensively on my old PowerBooks, which either suffer from flaky optical drives, or for which I don’t want to burn yet another temporary use CD.

  3. Michal Necasek says:

    If you have a CF card then you can use a CF to IDE adapter (hopefully you have something to plug that into) and make certain that the drive is really bootable.

    From experience I know that depending on how they were used, PCMCIA ATA devices may have a perfectly good partition table but not a suitable boot loader code in the MBR and/or no active partition. The utility mentioned takes care of that. Or, with CF to IDE adapters, good old FDISK /MBR, setting the active partition, and running FORMAT /S takes care of it.

    Anyway, in my case I know the card is good and that it really is bootable. There could be some additional magic I’m missing… or the BIOSes are just buggy.

  4. Michal Necasek says:

    The 750Cs won’t offer PCMCIA boot (my 750C does not, essentially identical machine). The 560 might. The 701 is different from everything else so no guesses. But I’m interested in your results.

  5. Jason says:

    you need a card that is an ATAPI card. IIRC the Iomega Clik PCMCIA PC Card was one such card. I remember NetBSD picking it up on one of those MIPS Windows CE handhelds from a long long long time ago.

  6. Trowa Barton says:

    I don’t appear to have any CF to PCMCIA adapters, so it’ll take a few days before I can report anything.

  7. Michal Necasek says:

    That’s very unlikely for the ThinkPads that don’t do ATAPI booting at all. The IBM document I referenced also clearly talks about ATA (not ATAPI) devices.

    That said, the ThinkPad documentation is extremely vague. PCMCIA booting is mentioned in the manuals but there’s no hint of what might or might not be expected to work. My 760E/760ED/760EL manual explicitly mentions that it’s possible to load an OS from a PC Card, but no details are given. The ThinkPad 370C manual (but I have no 370C) even suggests how to modify CONFIG.SYS if OS/2 is booted from a PC Card so that it could load the PCMCIA drivers without blowing away the boot drive.

  8. Tux2000 says:

    Just guessing: As far as I remember, CF cards can identify either as fixed media (i.e. harddisk) or as removable media. Most identify as removable. It’s just one bit in the ATA register set, and there are tools to change that bit. My guess is that the picky BIOS versions insist on booting from a “real hard drive”, i.e. fixed media, so you would need to toggle that bit.

  9. Michal Necasek says:

    Hmm, do you know of some existing tool that shows the state? That could be worth checking, and could indeed explain why some CF cards work and some don’t. Unfortunately the problem with the ThinkPads that refuse to boot from anything I threw at them is going to be something else.

  10. Andreas Kohl says:

    I only know of dump_cis and dump_cisreg from linux pcmcia-cs for reading. It’s not only simply setting a bit, also checksum has to be modified. CIS description is included in Appendix B of PC Card specification. It could also be a problem of CHS vs. LBA mapping.

  11. Michal Necasek says:

    According to the original CF+ spec (1.4, 2.0) they all identify as removable. The CF+ 3.0 spec adds an option to pretend that a CF+ device is non-removable magnetic storage. But… that all post-dates the ThinkPads we’re talking about by quite a few years. Also, the spec hints that in PCMCIA mode (what I’m trying to use) the original Word 0 value in Identify Device command should be used anyway (that’s where the Removable bit lives). Only True IDE mode ought to allow the CF cards to behave more like regular IDE disks.

    I’ll have to try to find the PCMCIA ATA spec though. It is possible that when modern CF cards differ from the older ones the ThinkPad BIOS could be confused/unhappy.

  12. S Duggan says:

    Looking further into the issue with my TP600E, it seems the 6xx series only supported booting from external CD ROM via PCMCIA. That would explain the lack of love for the CF to PCMCIA adapter. Coincidentally, I pulled the trigger on an IBM PCMCIA CD drive yesterday only because it came with a floppy cable and drive for the 701. Will be interesting to see if this at least works.

    On the TP forums, someone claimed to have booted DOS from a CF card on a 701 but it only worked with FreeDOS. MSDOS would apparently not play ball. Still, it seems to suggest that it is possible with the Butterfly, if not the workhorse 600.

  13. Trowa Barton says:

    I tried a couple times to report back.. not sure if the comments got lost in the void…

    My TP560 did boot off my CF card in the PCMCIA slot, my 750Cs and 701C didn’t appear to have any options to select it as a boot device.

  14. Michal Necasek says:

    That’s TP560 plain, right? No X or Z. So those seem to work pretty well. I wonder what’s wrong with the 760 TPs.

    The 750C definitely doesn’t have the option, even with the latest (1996) BIOS. Haven’t checked my 701C yet but if you say it’s not there I’m sure you’re right.

  15. Trowa Barton says:

    Yes plain 560. The 701 doesn’t even have a boot menu section in the bios.

  16. S Duggan says:

    The 701 has a simple toggle for boot priority. From what I can remember the default is ‘Smart’ and I think the other option is hard drive. Smart would suggest the bios probes for other bootable media before looking at the hard drive.

  17. Trowa Barton says:

    Yes, it has Smart and Conventional, I pulled out the HDD and it couldn’t find anything to boot from.

  18. Pingback: Removable CF Card, or Not | OS/2 Museum

  19. T Mark says:

    Found this site after dusting off my TP560, type 2640-50A. The hard drive is missing, but now I’m hopeful that maybe I can get it to run with a CF card…

    Should any PCMCIA to CF card reader work, or are there some that are better than others ? If anyone could recommend a particular model or ebay link, that would be great.

  20. Michal Necasek says:

    The adapters are purely mechanical (the equivalent of an extension cable). If it’s not outright broken, any adapter will work.

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