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ThinkPad 770: Error reading Drive Z, possible drive lettering off?

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armanicollezioni
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ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#1 Post by armanicollezioni » Sun Jan 06, 2019 9:21 pm

I have this problem when trying to factory reset it with the 770 Factory Restore disc. I was able to format the hard drive, but the part after that is what throws me off, and I get the error.

The thing is, when I go back into DOS, I see the drive lettering is off, too, as I see the CD-Drive is marked as "A:", which is reserved for the floppy drive, and I can't seem to redirect to Drive Z, as it does not exist, however C: and D: do exist.

How do I fix this?

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#2 Post by Thinkpad4by3 » Sun Jan 06, 2019 9:42 pm

That means that it is recognizing the CD-ROM drive as a boot device of a floppy. It can work like that and the CD-ROM is just in compatibility mode or DOS doesn't know its not on a CD-ROM. If you have an external floppy...boot from that and use drive letter R: I believe to access the CD-ROM and load it. I remember that I couldn't boot from a W95 disc but not sure about the repair disc.
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The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#3 Post by armanicollezioni » Sun Jan 06, 2019 9:48 pm

Thinkpad4by3 wrote:
Sun Jan 06, 2019 9:42 pm
That means that it is recognizing the CD-ROM drive as a boot device of a floppy. It can work like that and the CD-ROM is just in compatibility mode or DOS doesn't know its not on a CD-ROM. If you have an external floppy...boot from that and use drive letter R: I believe to access the CD-ROM and load it. I remember that I couldn't boot from a W95 disc but not sure about the repair disc.
I do have an ext. FDD, but how do I boot from it? Do I just change the boot order to the FDD first?

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#4 Post by Thinkpad4by3 » Sun Jan 06, 2019 11:02 pm

If you have a floppy disc in the drive...it should auto boot to there but putting it higher in the boot order is a good idea too.
Thinkpad4by3's Law of the Universe.

The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#5 Post by Bondi » Mon Jan 07, 2019 4:20 am

As they say, if nothing helps read the users' manual.
According to UM there should also be a recovery diskette. I guess it's created using some program from the CD.
Here is the manual for more details http://greyghost.mooo.com/pccbbs/mobiles/770esup.pdf
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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#6 Post by armanicollezioni » Thu Jan 17, 2019 11:43 pm

Thinkpad4by3 wrote:
Sun Jan 06, 2019 9:42 pm
That means that it is recognizing the CD-ROM drive as a boot device of a floppy. It can work like that and the CD-ROM is just in compatibility mode or DOS doesn't know its not on a CD-ROM. If you have an external floppy...boot from that and use drive letter R: I believe to access the CD-ROM and load it. I remember that I couldn't boot from a W95 disc but not sure about the repair disc.
I tried with my external drive, I did with no floppy and then I tried putting in a blank floppy, it just gave me a non-system disk error in return, it never gave me a command prompt. ;(

However I noticed that I can exit through a DOS prompt within the recovery CD, and I did so. I don't know what to do even; it seems my disc drive is drive C???? My external drive is also B. Apparently, A is reserved for a non-existent floppy drive. Very strange.
Last edited by armanicollezioni on Thu Jan 17, 2019 11:54 pm, edited 1 time in total.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#7 Post by Thinkpad4by3 » Thu Jan 17, 2019 11:52 pm

Then you have to format the floppy disk with the "format A:" command
Thinkpad4by3's Law of the Universe.

The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#8 Post by armanicollezioni » Thu Jan 17, 2019 11:57 pm

Thinkpad4by3 wrote:
Thu Jan 17, 2019 11:52 pm
Then you have to format the floppy disk with the "format A:" command
Should I just make my external floppy drive A:, and do format B (B is my ext. floppy drive)? I keep getting a "write protect error" when doing format A: for some reason. I'm sorry for all the questions, I've never ever had to do this before.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#9 Post by Thinkpad4by3 » Thu Jan 17, 2019 11:58 pm

armanicollezioni wrote:
Thu Jan 17, 2019 11:57 pm
Thinkpad4by3 wrote:
Thu Jan 17, 2019 11:52 pm
Then you have to format the floppy disk with the "format A:" command
Should I just make my external floppy drive A:, and do format B? I keep getting a "write protect error" when doing format A: for some reason. I'm sorry for all the questions, I've never ever had to do this before.
That means the little movable notch on the floppy disk AFAIK is open. Make sure that it is either closed or open or opposite of what it is now,
Thinkpad4by3's Law of the Universe.

The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#10 Post by armanicollezioni » Fri Jan 18, 2019 12:02 am

Thinkpad4by3 wrote:
Thu Jan 17, 2019 11:58 pm
armanicollezioni wrote:
Thu Jan 17, 2019 11:57 pm

Should I just make my external floppy drive A:, and do format B? I keep getting a "write protect error" when doing format A: for some reason. I'm sorry for all the questions, I've never ever had to do this before.
That means the little movable notch on the floppy disk AFAIK is open. Make sure that it is either closed or open or opposite of what it is now,
The notch wasn't open, but when I reversed it I just got a "General Protection Error." idk it's weird.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#11 Post by armanicollezioni » Fri Jan 18, 2019 12:07 am

Thinkpad4by3 wrote:
Thu Jan 17, 2019 11:58 pm
armanicollezioni wrote:
Thu Jan 17, 2019 11:57 pm

Should I just make my external floppy drive A:, and do format B? I keep getting a "write protect error" when doing format A: for some reason. I'm sorry for all the questions, I've never ever had to do this before.
That means the little movable notch on the floppy disk AFAIK is open. Make sure that it is either closed or open or opposite of what it is now,
Ok, so this is what I figured out, these are the partition letters:

CD-ROM Drive: A:\
External FDD: B:\
Hard drive: C:\

And when I eject the recovery CD or any CD, the drive is no longer recognized. I don't even know what's going on at this point aaaaaaaaaaaaaaaaaaaa it's so weird

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#12 Post by Thinkpad4by3 » Fri Jan 18, 2019 12:10 am

I told you the fact that MS-DOS sees the boot drive as A: no matter what the actual media is. I've burned MS-DOS boot disk to a HDD and it still boots under A:, as the floppy version of DOS is not the same as the installed copy...just on how it recognizes the boot drive.

Then B: is the floppy since usually when 1 drive is present A: and B: direct to the same but DOS sees the boot media as A: so the floppy gets B naturally as it sees its own boot media as another floppy.

And C: obviously is the main HDD.

Now is it clear?
Thinkpad4by3's Law of the Universe.

The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#13 Post by armanicollezioni » Fri Jan 18, 2019 12:26 am

Thinkpad4by3 wrote:
Fri Jan 18, 2019 12:10 am
I told you the fact that MS-DOS sees the boot drive as A: no matter what the actual media is. I've burned MS-DOS boot disk to a HDD and it still boots under A:, as the floppy version of DOS is not the same as the installed copy...just on how it recognizes the boot drive.

Then B: is the floppy since usually when 1 drive is present A: and B: direct to the same but DOS sees the boot media as A: so the floppy gets B naturally as it sees its own boot media as another floppy.

And C: obviously is the main HDD.

Now is it clear?
Got it.

Tried to format again with a different disc in the CD-Drive, and I thought I got success, but I got "Extended Error 19." Don't know what this means.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#14 Post by Thinkpad4by3 » Fri Jan 18, 2019 12:29 am

armanicollezioni wrote:
Fri Jan 18, 2019 12:26 am
Got it.

Tried to format again with a different disc in the CD-Drive, and I thought I got success, but I got "Extended Error 19." Don't know what this means.

Umm...you can't do that. When a CD is in MS-DOS as a readable device, it is NOT a writable device. It may as well be a ROM for all intents and purposes...hence CD-ROM.

You can only format floppies and HDDs through DOS. AFAIK there is no way to write to CDs in DOS outside of 3rd party (likely proprietary) tools as DOS was long since irrelevant when CD burning was around.
Thinkpad4by3's Law of the Universe.

The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#15 Post by armanicollezioni » Fri Jan 18, 2019 12:41 am

Thinkpad4by3 wrote:
Fri Jan 18, 2019 12:29 am
armanicollezioni wrote:
Fri Jan 18, 2019 12:26 am
Got it.

Tried to format again with a different disc in the CD-Drive, and I thought I got success, but I got "Extended Error 19." Don't know what this means.

Umm...you can't do that. When a CD is in MS-DOS as a readable device, it is NOT a writable device. It may as well be a ROM for all intents and purposes...hence CD-ROM.

You can only format floppies and HDDs through DOS. AFAIK there is no way to write to CDs in DOS outside of 3rd party (likely proprietary) tools as DOS was long since irrelevant when CD burning was around.
I honestly don't know what to do at this point.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#16 Post by Thinkpad4by3 » Fri Jan 18, 2019 1:04 am

First thing you should do is get a good night sleep.

Second...determine what you want to do. I recommend you get a CF card for an HDD for a total cost of 10$ and you will save a load of headache. Then you can set a VM(virtual machine) to a virtual hard disk(VHD) the size of the CF card(<8gb) and install the recovery disk using the VM. Then burn the VHD you created using the VM on the CF card, pop in the 770 and play!

Given you don't want to do that...I want you to try and find a floppy disc....anything that will go in the external floppy drive and try to do format A: . If you can find a USB floppy drive...plug it into a modern PC and make a bootable floppy. Due note that allbootdisks.com doesn't have working IMG burner apps. bootdisks.com or .org(I forget...just google it) has good ones that work with USB floppies...or better find a machine with a floppy drive.

Don't get frustrated and give up just yet...you will get a working (factory restored) OS on there...that's what were here for :D
Thinkpad4by3's Law of the Universe.

The efficiency of two screens equally sized with equal numbers if pixels are equal. The time spent by a 4:3 user complaining about 16:9 is proportional to the inefficiency working with a 16:9 display, therefore the amount of useful work extracted is equal.

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#17 Post by Bondi » Fri Jan 18, 2019 3:05 am

I recently made a factory recovery for my 755CD. The CD drive did not want to read the recovery disk after the hot-swap, so I did everythin g on a different laptop whch had both FDD and CD drive. And afterwards just moved the HDD back to 755CD. Worked perfectly.
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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#18 Post by fultontech » Fri Jan 18, 2019 4:01 pm

As I recall, on the 770x CDs the first thing was to load a virtual floppy in memory that was a subdirectory on the CD. That would be A:
Then the config.sys and autoexec.bat in A; would set the CD-ROM drive to something and the hard drive to something else, (I recall Z:, R:, and M: but don't quote me)
Then other batch files were called that unzipped and copied files to the hard drive after it was formatted and partitioned.
On the Win98 recovery CD set that went out, there was a bad file in one of the zip files from IBM for Yahoo or something else that wasn't cared about. The install/restore would fail, and you had to finish the restore by manually bypassing the one file at the command line.

Once you booted from the hard drive or a floppy though, the drive letters would be normal.
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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#19 Post by armanicollezioni » Tue Jan 22, 2019 2:17 pm

Thinkpad4by3 wrote:
Fri Jan 18, 2019 1:04 am
First thing you should do is get a good night sleep.

Second...determine what you want to do. I recommend you get a CF card for an HDD for a total cost of 10$ and you will save a load of headache. Then you can set a VM(virtual machine) to a virtual hard disk(VHD) the size of the CF card(<8gb) and install the recovery disk using the VM. Then burn the VHD you created using the VM on the CF card, pop in the 770 and play!

Given you don't want to do that...I want you to try and find a floppy disc....anything that will go in the external floppy drive and try to do format A: . If you can find a USB floppy drive...plug it into a modern PC and make a bootable floppy. Due note that allbootdisks.com doesn't have working IMG burner apps. bootdisks.com or .org(I forget...just google it) has good ones that work with USB floppies...or better find a machine with a floppy drive.

Don't get frustrated and give up just yet...you will get a working (factory restored) OS on there...that's what were here for :D
Okay, I found a bootable Norton Floppy Disk which my parents had about 20-something years ago, and it seems like it worked, as now my ext. FDD is drive A:. However, I can not format A:, as I get a "write protection error" while trying to format...

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Re: ThinkPad 770: Error reading Drive Z, possible drive lettering off?

#20 Post by armanicollezioni » Tue Jan 22, 2019 2:19 pm

fultontech wrote:
Fri Jan 18, 2019 4:01 pm
As I recall, on the 770x CDs the first thing was to load a virtual floppy in memory that was a subdirectory on the CD. That would be A:
Then the config.sys and autoexec.bat in A; would set the CD-ROM drive to something and the hard drive to something else, (I recall Z:, R:, and M: but don't quote me)
Then other batch files were called that unzipped and copied files to the hard drive after it was formatted and partitioned.
On the Win98 recovery CD set that went out, there was a bad file in one of the zip files from IBM for Yahoo or something else that wasn't cared about. The install/restore would fail, and you had to finish the restore by manually bypassing the one file at the command line.

Once you booted from the hard drive or a floppy though, the drive letters would be normal.
I got none of those drive letters when I put in my bootable floppy, it was either D: or E: but it said nothing was there.

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