[Coco] Remembering your CoCo Repacks

[gene heskett]

On 10/31/22 11:49, Bruce W. Calkins via Coco wrote:
>
>
> On 10/31/22 11:19, Allen Huffman via Coco wrote:
>>
>>> On Oct 31, 2022, at 7:32 AM, Francis Swygert via Coco 
>>> <coco at maltedmedia.com> wrote:
>>> …
>>> My main point is that with even IDE drives being hard to find, there 
>>> are still many SCSI drives available under $100 that would be 
>>> suitable for a CoCo (I checked NewEgg.com). I really liked
>>
>> I had no idea SCSI survived. I have noticed some of my USB devices 
>> identify as SCSIsomething in my Mac, so the protocol seems to be 
>> alive and well. Interesting. I wonder how much faster using a 
>> physical SCSI would be versus the modern SD card interfaces and such. 
>> Can we even use the speed? An SD card certainly has more storage than 
>> we could ever use.
>>
> SCSI has gone through several iterations. 
> <https://en.wikipedia.org/wiki/SCSI>  I have not followed 
> comparability between the generations however.  I did once connect a 
> SCSI 1 drive to my Disto hard drive interface.  It was limited to the 
> accessing the first 256 bytes of the 512 byte granules.  I never did 
> find a way to see the other half of those granules.
>
> I generally ran the system with an Adaptec SCSI-2-MFM card with 2 big 
> MFM drives.  It is still set up, but has been in storage 18 years now.
>
I still have one of those setups too.
> Bruce W.
>
Using nitros9, that is not a problem, I saw the whole 132 megs of a 
maxtor 7120S in the disto, and when I had
converted to a trinity interface that Mark sold, I could see all of both 
1 Gigabyte Seagate scsi drives after I had
retired them out of a full blown Amiga 2000.

That only using the first 256 bytes of a 512 byte formatted drives 
sector was 100% the underlying rsdos limitation.

There is one other problem that s/b mentioned re the disto 4n1 kit, the 
isolation diode is a common si diode with
its normal .65 volt voltage drop,  That drop lowered the logic one noise 
margin to about 200 millivolts, and any
drop in the 5 volts ruined what was left. Switching that diode out for a 
schotkey made a flaky system bullet proof.

That is also a lesson none of the scsi card makers for the amiga 
computers never learned. I had when I was the
CE at WDTV, to fix that in every amiga we had.  And at one point we had 
half a dozen doing graphics rendering for
commercial production.  Amigados never had a cron, so Jim Hines and I 
wrote a proper cron in Arexx, so those
computers. which were heavily used during the newscasts, were busy 
renderiing the next fawncy commercial 30 seconds
after the newscasts ended.

Then the two head guy's at commie fled to burmuda with the accounts 
receivable where nobody could touch them.
It was fun while it lasted though.


Cheers, Gene Heskett.
-- 
"There are four boxes to be used in defense of liberty:
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-Ed Howdershelt (Author, 1940)
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  - Louis D. Brandeis
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