Hi computer history enthusiasts, I hope that it is ok that I signed on to your list. I am from germany and I'm looking for information about the Zilog System 8000. I know that you owned at least one in the past. I don't know if you still have it, but I hope so :) Bit more about what the background of my question is: - I own a Zilog System 8000/21 but neither do I have a harddrive for it nor do I have a working tapedrive or any tape medias. - A friend of mine also got a Zilog System 8000/21 lately but his harddrive is broken (heads do not find track 0), and his tape drive capstan went to "gum". He got a noriginal Zilog ZEUS (Zilogs UNIX) tape media but with the broken drives no way of backing it up or retrieve at least its contents. - Today I found out, that another enthusiast from a local university also has a System 8000/32 (newer than /21 with SMD harddisks) in the uni museum. He has a dying harddrive, a working tape drive but no media. You see... lots of "missing", "dying" and so on.... I wonder in what condition your System 8000 is. In the past (2009 and 2012 iirc) I had contact with Jeff Jonas. He was trying to back up the tapes you guys have for the system. But iirc his problem was also, that the capstan of your System 8000s tape drive went literally to fluid.... I wonder if there is any status update? We really could need those tape images and it looks like there are not much System 8000s around any one - and even less installation medias. Beware - even if the tape might fit into a regular QIC-11 Tape drive - its encoding is MFM - so far from any QIC standard. It will only work with the original Tape drive from the System 8000. Please be extremly cautionous with the tape medias. They might be the only ones left still be readable... who knows.... Before you try anything - try it with unimportant tapes many times before you risk the Zilog tape. Backing up over serial can not be recommended as the tape will fetch data more then 10th as fast as the SIO can pump it to a remote machine. This will lead to a permanent stop/start mode the tape will work in resulting in maximum stress for the Zilog tape. I would _not_ recommend this. You see - I'm quite careful when it comes to your tape, but still seeking out for any posibility to aquire a dump of it somehow. Any information about "my" S8000? Feel free to look it up at http://www.pofo.de/S8000/ Regards, Oliver!
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that you owned at least one in the past. I don't know if you still have it, but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
I had an Everex Pentium-S with 8 megs of RAM wander into my life the other day. It has DOS 6.22 installed and seems to be in wonderfully clean condition. It came out of an audiologist’s office, apparently, and has maintenance stickers on it as late as 2014. I don’t have any of the gadgets for hearing testing that it interfaces with, but the computer itself. Does this have any value to anyone on the list? I’m trying to decide if it’s going to the scrap pile at the dump.
Evan Koblentz via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that you owned at least one in the past. I don't know if you still have it, but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Ok, I'll look forward to that - hoping that it will happen some day ;) Just remember the tapes are quite rare and need be handled with care. Your tape drive has also a capstan which went to goo over the past 30 years, so please do not just put them into the drive without fixing that first. Otherwise the tapes and their contents will be gone forever.... Regards, Oliver
Speaking of rare QIC tapes, I've undertaken quite an effort to read previously unreadable or unknown QIC tapes: https://youtu.be/BfKUJmPSam0 Soon, I'll do a video demonstration of the programs I wrote which read the data from the logic analyzer captures. I'm pretty excited about the success of this project. Also, maybe on topic here, I was also dialoguing with MattisLind from Sweden about preserving some rare Zilog 8000 Zeus OS tapes, where he doesn't have any hardware that will read them. http://bit.ly/1PxqcNW He asked if I was going to come to any of the Infoage/MARCH events such as Festivus, and that's where we left the conversation off. It would be a shame if he came with the tapes all the way from Sweden, and I missed him. On Tue, Nov 17, 2015 at 1:55 AM, Oliver Lehmann via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that
you owned at least one in the past. I don't know if you still have it, but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Ok, I'll look forward to that - hoping that it will happen some day ;)
Just remember the tapes are quite rare and need be handled with care. Your tape drive has also a capstan which went to goo over the past 30 years, so please do not just put them into the drive without fixing that first.
Otherwise the tapes and their contents will be gone forever....
Regards, Oliver
-- Thanks, -AJ http://MicrotechM1.blogspot.com
Hi, yeah - had also contact with Mattis in the past about his tapes. He also currently no way in backing up his tapes. Even if the tapes are fit into QIC-11 tape drives, just remember that no regular QIC tape will be able to read them. They are MFM encoded. Here you'll find the manual of the drive used in the S8000 http://www.bitsavers.org/pdf/dei/CMTD-3400S2_4tk6400bpi_1979.pdf Attached you'll find a text file I gathered from somewhere stating that it is the service manual of the drive. You'll see that its "features" are a bit of from QIC standard - it was made in a time where QIC wasn't that popular. But maybe you're backing up strategy with a logic analyzer does not care about all that? I wonder how the recorded data could be then possibly restored on other tapes to create a copy for example? Microtech Dart <microtechdart@gmail.com> wrote:
Speaking of rare QIC tapes, I've undertaken quite an effort to read previously unreadable or unknown QIC tapes:
Soon, I'll do a video demonstration of the programs I wrote which read the data from the logic analyzer captures.
I'm pretty excited about the success of this project.
Also, maybe on topic here, I was also dialoguing with MattisLind from Sweden about preserving some rare Zilog 8000 Zeus OS tapes, where he doesn't have any hardware that will read them.
He asked if I was going to come to any of the Infoage/MARCH events such as Festivus, and that's where we left the conversation off. It would be a shame if he came with the tapes all the way from Sweden, and I missed him.
On Tue, Nov 17, 2015 at 1:55 AM, Oliver Lehmann via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that
you owned at least one in the past. I don't know if you still have it, but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Ok, I'll look forward to that - hoping that it will happen some day ;)
Just remember the tapes are quite rare and need be handled with care. Your tape drive has also a capstan which went to goo over the past 30 years, so please do not just put them into the drive without fixing that first.
Otherwise the tapes and their contents will be gone forever....
Regards, Oliver
--
Thanks, -AJ http://MicrotechM1.blogspot.com
Correct, my read process would not care what the format is, it would capture the data pulses regardless. It would then be up to the programs that I write in order to decode the format into data. It's a lot of work, but very rewarding when it is successful. Once the data pulses are properly captured, then they can be converted into the original bits at any time, once the format is decoded properly. A monumental task, at least it has been for me so far, but it seems to be working out quite well for all of the formats that I've tackled so far. I have not yet tackled MFM on QIC cartridges like this, so it sounds like a very interesting challenge, but it seems doable. I'm browsing the manual now, very good information. I'm seeing a 4-track system, with the track order <http://bitsavers.informatik.uni-stuttgart.de/pdf/dei/CMTD-3400S2_4tk6400bpi_1979.pdf#page=23> being the same as the Kennedy 6450, for which I have tapes, but no drive: http://microtechm1.blogspot.com/2015/09/kennedy-6450-tape-drive-data-format.... Anyway, I've successfully turned the pulses on all of those tracks into data with my programs, with only a few block errors that I'm working on painstakingly correcting. I see the MFM discussed between PDF pages 38-40 <http://bitsavers.informatik.uni-stuttgart.de/pdf/dei/CMTD-3400S2_4tk6400bpi_1979.pdf#page=38>. Section 4.5.1 seems to tell me exactly how to write my program to read this (as far as the data pulse interpretation). I'll need to look at that again later. So far this looks like a really good manual with lots of good technical data on the format. I wish I would have started my project with a manual that is this thorough or well organized. As far as transferring the data pulses to new tapes, well, I haven't built anything to do this yet, but it seems to me to be fairly straightforward to accomplish this. This is something I've wanted to do for myself for some time now. There are so many variables, and I'd have to tackle them one by one. This is actually something that I've discussed building with the assistance of Jim Drew, creator of the SuperCard Pro for floppy disks, and something I hope that I can accomplish in the not-so-distant future. Thanks for keeping this stuff alive. Maybe someday I can help you archive these very scarce and nearly extinct data/programs. More later, I hope. This is quite interesting for me, but I must sleep now. Check back with me soon on this, if you like, please. Thanks for the discussion, -AJ http://MightyFrame.com http://MicrotechM1.blogspot.com On Tue, Nov 17, 2015 at 2:25 AM, Oliver Lehmann via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Hi,
yeah - had also contact with Mattis in the past about his tapes. He also currently no way in backing up his tapes.
Even if the tapes are fit into QIC-11 tape drives, just remember that no regular QIC tape will be able to read them.
They are MFM encoded.
Here you'll find the manual of the drive used in the S8000 http://www.bitsavers.org/pdf/dei/CMTD-3400S2_4tk6400bpi_1979.pdf
Attached you'll find a text file I gathered from somewhere stating that it is the service manual of the drive. You'll see that its "features" are a bit of from QIC standard - it was made in a time where QIC wasn't that popular.
But maybe you're backing up strategy with a logic analyzer does not care about all that? I wonder how the recorded data could be then possibly restored on other tapes to create a copy for example?
Microtech Dart <microtechdart@gmail.com> wrote:
Speaking of rare QIC tapes, I've undertaken quite an effort to read
previously unreadable or unknown QIC tapes:
Soon, I'll do a video demonstration of the programs I wrote which read the data from the logic analyzer captures.
I'm pretty excited about the success of this project.
Also, maybe on topic here, I was also dialoguing with MattisLind from Sweden about preserving some rare Zilog 8000 Zeus OS tapes, where he doesn't have any hardware that will read them.
He asked if I was going to come to any of the Infoage/MARCH events such as Festivus, and that's where we left the conversation off. It would be a shame if he came with the tapes all the way from Sweden, and I missed him.
On Tue, Nov 17, 2015 at 1:55 AM, Oliver Lehmann via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that
you owned at least one in the past. I don't know if you still have it,
but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Ok, I'll look forward to that - hoping that it will happen some day ;)
Just remember the tapes are quite rare and need be handled with care. Your tape drive has also a capstan which went to goo over the past 30 years, so please do not just put them into the drive without fixing that first.
Otherwise the tapes and their contents will be gone forever....
Regards, Oliver
--
Thanks, -AJ http://MicrotechM1.blogspot.com
-- Thanks, -AJ http://MicrotechM1.blogspot.com
On 11/17/2015 04:44 AM, Microtech Dart via vcf-midatlantic wrote:
As far as transferring the data pulses to new tapes, well, I haven't built anything to do this yet, but it seems to me to be fairly straightforward to accomplish this.
As QIC tapes have now started to die faster than the drives, this is probably becoming moot. It might make more sense to develop emulators for the drives themselves, to get the bits into the machines. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
Yes, exactly what I was thinking about trying to do myself, eventually. I've discussed this very thing with both David Gesswein (maker of the MFM emulator http://www.pdp8online.com/mfm/mfm.shtml ) and Jim Drew ( Maker of the SuperCard Pro http://www.cbmstuff.com/proddetail.php?prod=SCP ) Their experience in successfully building readers and emulators of hard drives and floppy disks/drives is something I would need to draw upon when I am ready to tackle that level of the project. I'm curious if anyone else has heard of this being attempted as of yet? On Tue, Nov 17, 2015 at 1:53 PM, Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/17/2015 04:44 AM, Microtech Dart via vcf-midatlantic wrote:
As far as transferring the data pulses to new tapes, well, I haven't built anything to do this yet, but it seems to me to be fairly straightforward to accomplish this.
As QIC tapes have now started to die faster than the drives, this is probably becoming moot. It might make more sense to develop emulators for the drives themselves, to get the bits into the machines.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
-- Thanks, -AJ http://MicrotechM1.blogspot.com
I intend a phaseout for all my stuff after I copy two things: BSD/OS and SCO Sent from my iPhone
On Nov 17, 2015, at 11:53, Dave McGuire via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/17/2015 04:44 AM, Microtech Dart via vcf-midatlantic wrote: As far as transferring the data pulses to new tapes, well, I haven't built anything to do this yet, but it seems to me to be fairly straightforward to accomplish this.
As QIC tapes have now started to die faster than the drives, this is probably becoming moot. It might make more sense to develop emulators for the drives themselves, to get the bits into the machines.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
(All my QIC I mean) I appear to have finally settled on DLT. ;) Sent from my iPhone
On Nov 17, 2015, at 19:24, Cory Smelosky via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I intend a phaseout for all my stuff after I copy two things:
BSD/OS and SCO
Sent from my iPhone
On Nov 17, 2015, at 11:53, Dave McGuire via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/17/2015 04:44 AM, Microtech Dart via vcf-midatlantic wrote: As far as transferring the data pulses to new tapes, well, I haven't built anything to do this yet, but it seems to me to be fairly straightforward to accomplish this.
As QIC tapes have now started to die faster than the drives, this is probably becoming moot. It might make more sense to develop emulators for the drives themselves, to get the bits into the machines.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
On 11/16/2015 4:16 PM, Evan Koblentz via vcf-midatlantic wrote:
I hope that it is ok that I signed on to your list. I am from germany Welcome!
and I'm looking for information about the Zilog System 8000. I know that you owned at least one in the past. I don't know if you still have it, but I hope so :) We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Note I've been told QIC tapes of this age most likely (95% chance) have to be "baked" to prevent them from turning to mush against the drive heads. (I'm not 100% sure how the baking process is gone about, but I believe it requires disassembling the cartridge and removing the tape spool, and wrapping the tape around a special metal spindle, then heating it to a certain temperature for a few hours. I could be way off here.) Also, to recover the data from these tapes, given the drive capstans (and cartridge capstans?) always seem to turn to goo and we're not sure if the z80-based interface card works or not... Would it make more sense to get any old QIC drive that is sufficiently old enough to be hackable but has intact rollers, and (after baking the tapes) use an FPGA development board and some breadboarded analog amplifier magic to directly control the QIC motor and tap the QIC drive heads for the 4 tracks, and either record them as analog waveforms at a high samplerate, or log time-deltas (in 50mhz clocks) between flux transitions? Then decode the resulting flux stream entirely in software. 50mhz may be extreme overkill, its possible digital sampling at 192khz or twice that may be fast enough, I don't really know... I could have sworn someone on this list, or in another similar list (classiccmp?) had already worked out a setup for decoding tapes just like this... -- Jonathan Gevaryahu jgevaryahu@gmail.com jgevaryahu@hotmail.com
Jonathan, I like your thinking! Actually, I've already done something that works well for a lot of what you mention. Please watch this YouTube video I created for my Universal QIC tape reader. https://youtu.be/BfKUJmPSam0 I've read a number of different head/track configurations with this, by finding the tracks of the 9 that overlap with the 4, and choosing the correct direction on my manual switch control. Very much a trial-and-error process to get there. This has worked very well for me on the handful of odd-format tapes that I have read so far. One of those formats is a really weird 4-track format, and here's my page on the breakdown of that, and how I read that 4-track with my 9-track reader. http://microtechm1.blogspot.com/2015/09/kennedy-6450-tape-drive-data-format.... I hope these resources inspire you for a solution to save this data! Also, about the drive-wheel turning to goo, all of the drive wheels in my drives did this, and I've had them all replaced by Terry's Rubber Wheels ( http://terrysrubberwheels.com ), so using a good rebuilt wheel is very important in my opinion. Many here have also rebuilt their own drive wheels. I do have experience baking these tapes now. (Not nearly as much as others here, though). I hope to create a YouTube video for that in the next few days, because that's one of the things I would have found extremely helpful when starting to learn about QIC tape restoration. My success with that was me putting into practice advice I've received from many who post here regularly. But, until I create that YouTube video, please see these posts, which give a lot of good instruction on the matter. The advice in these posts is exactly what I followed, which gave me success: http://bit.ly/2176PiI The internal tape belt/band is an issue as well, which probably should be replaced after the old one was removed for tape baking. I have created 2 videos on that as well, and linked the discussions of those more experienced than I on that topic, which inspired my processes, below each video. 1) https://youtu.be/70PDHfdbsvY 2) https://youtu.be/Ku1lKY-2mGs I hope this helps! -AJ On Thu, Nov 19, 2015 at 10:46 PM, Jonathan Gevaryahu via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/16/2015 4:16 PM, Evan Koblentz via vcf-midatlantic wrote:
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that
you owned at least one in the past. I don't know if you still have it, but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Note I've been told QIC tapes of this age most likely (95% chance) have to be "baked" to prevent them from turning to mush against the drive heads. (I'm not 100% sure how the baking process is gone about, but I believe it requires disassembling the cartridge and removing the tape spool, and wrapping the tape around a special metal spindle, then heating it to a certain temperature for a few hours. I could be way off here.)
Also, to recover the data from these tapes, given the drive capstans (and cartridge capstans?) always seem to turn to goo and we're not sure if the z80-based interface card works or not... Would it make more sense to get any old QIC drive that is sufficiently old enough to be hackable but has intact rollers, and (after baking the tapes) use an FPGA development board and some breadboarded analog amplifier magic to directly control the QIC motor and tap the QIC drive heads for the 4 tracks, and either record them as analog waveforms at a high samplerate, or log time-deltas (in 50mhz clocks) between flux transitions? Then decode the resulting flux stream entirely in software. 50mhz may be extreme overkill, its possible digital sampling at 192khz or twice that may be fast enough, I don't really know...
I could have sworn someone on this list, or in another similar list (classiccmp?) had already worked out a setup for decoding tapes just like this...
-- Jonathan Gevaryahu jgevaryahu@gmail.com jgevaryahu@hotmail.com
-- Thanks, -AJ http://MicrotechM1.blogspot.com
Correction on http://www.terrysrubberrollers.com , sorry for that bad link. On Thu, Nov 19, 2015 at 11:18 PM, Microtech Dart <microtechdart@gmail.com> wrote:
Jonathan, I like your thinking!
Actually, I've already done something that works well for a lot of what you mention. Please watch this YouTube video I created for my Universal QIC tape reader.
I've read a number of different head/track configurations with this, by finding the tracks of the 9 that overlap with the 4, and choosing the correct direction on my manual switch control. Very much a trial-and-error process to get there. This has worked very well for me on the handful of odd-format tapes that I have read so far. One of those formats is a really weird 4-track format, and here's my page on the breakdown of that, and how I read that 4-track with my 9-track reader.
http://microtechm1.blogspot.com/2015/09/kennedy-6450-tape-drive-data-format....
I hope these resources inspire you for a solution to save this data!
Also, about the drive-wheel turning to goo, all of the drive wheels in my drives did this, and I've had them all replaced by Terry's Rubber Wheels ( http://terrysrubberwheels.com ), so using a good rebuilt wheel is very important in my opinion. Many here have also rebuilt their own drive wheels.
I do have experience baking these tapes now. (Not nearly as much as others here, though). I hope to create a YouTube video for that in the next few days, because that's one of the things I would have found extremely helpful when starting to learn about QIC tape restoration. My success with that was me putting into practice advice I've received from many who post here regularly.
But, until I create that YouTube video, please see these posts, which give a lot of good instruction on the matter. The advice in these posts is exactly what I followed, which gave me success:
The internal tape belt/band is an issue as well, which probably should be replaced after the old one was removed for tape baking. I have created 2 videos on that as well, and linked the discussions of those more experienced than I on that topic, which inspired my processes, below each video.
1) https://youtu.be/70PDHfdbsvY
2) https://youtu.be/Ku1lKY-2mGs
I hope this helps!
-AJ
On Thu, Nov 19, 2015 at 10:46 PM, Jonathan Gevaryahu via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/16/2015 4:16 PM, Evan Koblentz via vcf-midatlantic wrote:
I hope that it is ok that I signed on to your list. I am from germany
Welcome!
and I'm looking for information about the Zilog System 8000. I know that
you owned at least one in the past. I don't know if you still have it, but I hope so :)
We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Note I've been told QIC tapes of this age most likely (95% chance) have to be "baked" to prevent them from turning to mush against the drive heads. (I'm not 100% sure how the baking process is gone about, but I believe it requires disassembling the cartridge and removing the tape spool, and wrapping the tape around a special metal spindle, then heating it to a certain temperature for a few hours. I could be way off here.)
Also, to recover the data from these tapes, given the drive capstans (and cartridge capstans?) always seem to turn to goo and we're not sure if the z80-based interface card works or not... Would it make more sense to get any old QIC drive that is sufficiently old enough to be hackable but has intact rollers, and (after baking the tapes) use an FPGA development board and some breadboarded analog amplifier magic to directly control the QIC motor and tap the QIC drive heads for the 4 tracks, and either record them as analog waveforms at a high samplerate, or log time-deltas (in 50mhz clocks) between flux transitions? Then decode the resulting flux stream entirely in software. 50mhz may be extreme overkill, its possible digital sampling at 192khz or twice that may be fast enough, I don't really know...
I could have sworn someone on this list, or in another similar list (classiccmp?) had already worked out a setup for decoding tapes just like this...
-- Jonathan Gevaryahu jgevaryahu@gmail.com jgevaryahu@hotmail.com
--
Thanks, -AJ http://MicrotechM1.blogspot.com
-- Thanks, -AJ http://MicrotechM1.blogspot.com
By the way, the DEI drive has a Controller and Codec board as shown on page 19 in http://bitsavers.informatik.uni-stuttgart.de/pdf/dei/CMTD-3400S2_4tk6400bpi_... So you already get NRZ Data out of it. You could just "select" the tape and then let the tape read the whole tape at once and record the NRZdata incl. clock..... Oliver Jonathan Gevaryahu via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/16/2015 4:16 PM, Evan Koblentz via vcf-midatlantic wrote:
I hope that it is ok that I signed on to your list. I am from germany Welcome!
and I'm looking for information about the Zilog System 8000. I know that you owned at least one in the past. I don't know if you still have it, but I hope so :) We have it, but we haven't done much with it. Perhaps at our next repair event. We have workshops here every few months.
Note I've been told QIC tapes of this age most likely (95% chance) have to be "baked" to prevent them from turning to mush against the drive heads. (I'm not 100% sure how the baking process is gone about, but I believe it requires disassembling the cartridge and removing the tape spool, and wrapping the tape around a special metal spindle, then heating it to a certain temperature for a few hours. I could be way off here.)
Also, to recover the data from these tapes, given the drive capstans (and cartridge capstans?) always seem to turn to goo and we're not sure if the z80-based interface card works or not... Would it make more sense to get any old QIC drive that is sufficiently old enough to be hackable but has intact rollers, and (after baking the tapes) use an FPGA development board and some breadboarded analog amplifier magic to directly control the QIC motor and tap the QIC drive heads for the 4 tracks, and either record them as analog waveforms at a high samplerate, or log time-deltas (in 50mhz clocks) between flux transitions? Then decode the resulting flux stream entirely in software. 50mhz may be extreme overkill, its possible digital sampling at 192khz or twice that may be fast enough, I don't really know...
I could have sworn someone on this list, or in another similar list (classiccmp?) had already worked out a setup for decoding tapes just like this...
-- Jonathan Gevaryahu jgevaryahu@gmail.com jgevaryahu@hotmail.com
On 11/16/2015 04:13 PM, Oliver Lehmann via vcf-midatlantic wrote:
Bit more about what the background of my question is:
- I own a Zilog System 8000/21 but neither do I have a harddrive for it nor do I have a working tapedrive or any tape medias. - A friend of mine also got a Zilog System 8000/21 lately but his harddrive is broken (heads do not find track 0), and his tape drive capstan went to "gum". He got a noriginal Zilog ZEUS (Zilogs UNIX) tape media but with the broken drives no way of backing it up or retrieve at least its contents. - Today I found out, that another enthusiast from a local university also has a System 8000/32 (newer than /21 with SMD harddisks) in the uni museum. He has a dying harddrive, a working tape drive but no media.
You see... lots of "missing", "dying" and so on....
Hello Oliver, I think you and I discussed Zilog System 8000 stuff many years ago. I had a Model 31 for a long time, back in the late 1980s. It was a great system. Its only real drawback was the lack of networking capability. I still miss that system, but I sold it before I became old and sentimental. I currently have a Model 21, but its hard drive has failed (it's the SMD version) and the tape drive roller has predictably turned to goo. I will address the roller problem at some point, when I start to dig into the system. Otherwise the system comes up and executes its ROM-based code. It is very important that ZEUS install tapes be preserved. They are, as you have observed, nearly impossible to find. This was the "largest" application for the Z8000 processor architecture, and it's exactly the application it was designed for...it was used in lots of other places but couldn't really "shine" in those areas. For example, I have an EDAX system on my electron microscope that uses a Z8000 running ROM-based code as a coprocessor for number crunching. The Z8000 has significant strengths for multitasking and timesharing applications, and ZEUS on the System 8000 family is, to my knowledge, the only place it was taken advantage of. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
Dave McGuire via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Hello Oliver, I think you and I discussed Zilog System 8000 stuff many years ago.
Yes indeed - I remember your name :) So it goes up to 7 locations I know of where S8000s are still around... 3 in .de 1 in .se 1 in .uk 2 in .us (you and MARCH) I know of 3 tape sets. One in .se, one in .uk and the one MARCH has. And I searched the internet in the past 6 years carefully. If I didn't missed someone else - thats it... either someone got some in a dark cellar and keeping it a secret or there aren't just much S8000s left in the world ;)
participants (7)
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Cory Smelosky -
Dave McGuire -
David Hoelzer -
Evan Koblentz -
Jonathan Gevaryahu -
Microtech Dart -
Oliver Lehmann