[Coco] SCSI/SASI HD interfaces...

[Stephen H. Fischer]

Gene has not posted lately. He and I used real SCSI drives with the Disto controller.

When my Disto controller and the 6309 CPU failed at the same time I quickly decided to stop using my real CoCo(s).

I had to declare everything in my electronics room as electronic waste to be recycled (State law).

Lots of people would treasure everything in that room but my attempts to give stuff away stopped when everything was reported to be not working. As well as what I try to use. 

I even had for a short time a eight inch disk.

At the peak there were 8-12 electronic surplus stores local to me.

The first and the remaining one is still open and I can get it's webpage to open again.

 http://www.halted.com/

I may have more IC's with legs than they have now

SHF

P.S. Get some real SCSI drives, you will fail otherwise to use your time well.

----- Original Message ----- 
From: "Bruce W. Calkins" <brucewcalkins at charter.net>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Friday, April 03, 2015 5:54 PM
Subject: Re: [Coco] SCSI/SASI HD interfaces...


> More details on my Disto hard drive set up.
> 
> The 3-in-1 adapter provided a SASI pin out that went to a Adaptec -??4001 
> card the same width and length as a 5.25" drive.  This drive had SASI cables 
> on one end and MFM cables on the other for up to 2 MFM drives.  There are 
> some addressing pins on the SASI end too.  I eventually got two spare cards 
> and attempted to hook up a second set of two hard drives as the Disto 
> documentation indicated was possible, however I did not have success at the 
> time.  Later I got the book from Adaptec for the card and discovered that I 
> need to cut a trace on one of the cards to get two cards to address properly 
> together.  I moved about then and have not had the chance to attempt the 4 
> hard drive setup again.  (It will need a GOOD power supply to power up those 
> 4 full height 8 platter, 16 head 5.25" drivers too.)
> 
> I have been tempted to break down the system as I have 4 of the Maxtor 
> XT-2190 MFM hard drives and the asking prices listed on eBay have gotten my 
> attention a time or two.  The drives were the largest MFM drives made and 
> were popular with some early audio processing equipment.  Backing up those 
> drives generally took 12 to 18 hours each for the 2 RGB-DOS partitions and 
> DSAVEing the OS-9 partition.  The 768k Disto RAM disk pack did help smooth 
> out the RGB-DOS backups.  It would have been a dream system in 1978, but I 
> did not get most of it until after 1993.  Hopefully one of these days I'll 
> find the right "Round-Tuit" and get that 1 megabyte + 768k CoCo 3 system 
> running again.
> 
> 
> Bruce W.
> 
> ===================
> 
> 
> 
> ----- Original Message ----- 
> 
> From: "Francis Swygert"
> 
>> Date: Fri, 3 Apr 2015 03:03:35 -0400
>> From: Bill Pierce
> 
>>
>> Both Kenton and LR Tech (Owl-Ware) were scsi hard drive systems and were 
>> regularly advertised in Rainbow.
>> ============================================
>> I don't know the differences, but the Disto controllers were SASI and only 
>> supported two devices, IIRC. They used less than 50 pins, but I think a 
>> lot of the grounds were left out. IIRC SASI/SCSI used alternating grounds 
>> (25 grounds, 25 signals). Disto may have dropped some of the signal pins 
>> as well. Most of the SCSI controllers for the CoCo only supported hard 
>> drives -- not much else was ever used on a CoCo, and it was quite the 
>> unusual CoCo user that had more than two HDs connected -- most only had 
>> one.
>>
>> Frank Swygert
> 
> 
> 
> 
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