[vcf-midatlantic] Zilog System 8000

[Microtech Dart]

Correction on http://www.terrysrubberrollers.com , sorry for that bad link.

On Thu, Nov 19, 2015 at 11:18 PM, Microtech Dart <microtechdart at 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.
>
> 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.html
>
> 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 at 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 at gmail.com
>> jgevaryahu at hotmail.com
>>
>>
>
>
> --
>
> Thanks,
> -AJ
> http://MicrotechM1.blogspot.com
>



-- 

Thanks,
-AJ
http://MicrotechM1.blogspot.com