Re: Now have a 8280 formatted 8" disk (success!)

----- Original Message ----- 
From: "Rob Clarke" <crock@clarke-family.org.uk>
To: <cbm-hackers@musoftware.de>
Sent: Wednesday, February 15, 2017 6:31 PM
Subject: Re: Now have a 8280 formatted 8" disk (success!)


> Woo-hoo! It works. :-)
> 
> Following Mike S's comment I made my punched hole a bit bigger and now 
> it's formatting successfully, but wow it is slow! It takes around 12 
> minutes and 40 seconds to complete, so several times longer than a 1541. 
> It  seems to be a 2 pass format process. The first pass is quite fast, 
> taking about 20 seconds to step through the 77 tracks, but the second 
> pass is very slow, taking around 9 seconds per track. I seem to remember 
> reading somewhere that tha BAM maps out bad sectors, so I'm guessing 
> that the second pass is checking for bad sectors. When it completes the 
> second pass, the head steps backwards and forwards several times before 
> finally finishing.
> 
> Also, it takes a very long time the first time you read the directory 
> with the head stepping several times, but whern it does I get:
> 
> 0 "test disk            " 99 3a
> 
> 3946 blocks free.
> 
> So the main finding from this is that it must be a double sided disk, if 
> you use a single sided, it will fail with a read error.
> 
> cheers, Rob
> 
> 
> On 15/02/2017 22:54, Mike Stein wrote:
>> ----- Original Message -----
>> From: "Rob Clarke" <crock@clarke-family.org.uk>
>> To: <cbm-hackers@musoftware.de>
>> Sent: Wednesday, February 15, 2017 3:41 PM
>> Subject: Re: Need an 8280 formatted 8" disk (progress!)
>>
>>
>>> ...The 8280 needs double sided disks, as it explicitly says
>>> "Double sided diskettes must be used and must be formatted with the
>>> HEADER command before using for system operation. "at the beginning of
>>> section 4 on the CBM_8280_Specifications.pdf document on your site Bo.
>> Yeah, what confused me was this spec, also on Bo's site:
>>
>> http://www.zimmers.net/cbmpics/dlieee2.html
>> Model    : 8280
>> Type     : Dual 8" Floppy Disk
>> Media    : Single Sided, Double Density
>> Capacity : 1024K per disk, or 2048K total
>> Interface: IEEE-488
>> Dos      : CBM DOS 3.0
>> Notes    : Huuuuuugggggggeeee!!!!> I tried last night to cut my own index hole using a google
>>> image of a double sided disk as a measurement reference, but failed. :-(
>> Maybe try making it a little larger in case it's misaligned a bit? Size is not really critical as long as the index sensor can see the LED.
>>
>>> Mike S., the drives in my 8280 are TM848-2's, which are the double sided
>>> ones but which are *not* MPU controlled, like the 828-1E and 828-2E.
>> That's what I assumed from looking at Andre's picture, but the specs and users manual on Bo's site are for the 848-E.
>>
>> Good luck!
>>
>> m
>>
>>
>>> cheers, Rob
>>>
>>>
>>> On 15/02/2017 21:01, Mike Naberezny wrote:
>>>> On 2/15/17 11:20 AM, Bo Zimmerman wrote:
>>>>> The disk also has a write-protect tab on the bottom-right of the
>>>>> disk, near
>>>>> where the read/write exposure strip is.  Came right out of the damn
>>>>> box that
>>>>> way.  Could the write-protect logic on 8" disks be opposite to 5.25"?
>>>>> That is,
>>>>> write is enabled when the tab is covered, and disabled when exposed?
>>>> Yes.  The write protect notch on 8" disks has the opposite behavior of
>>>> 5.25" disks.  I recently repaired a CGRS Microtech PEDISK II 8" disk
>>>> system for PET.  I had to work through the same issues with the index
>>>> hole location and write protect notch.
>>>>
>>>> Now that my PEDISK II system is working, I can provide a known good 8"
>>>> single sided, soft sectored, single density (FM) formatted disk with
>>>> 77 tracks, 26 sectors per track, and a 128 byte sector length.  Disks
>>>> from my system have been successfully read on another.  The filesystem
>>>> is not be compatible with CBM drives but the disk can be used to test
>>>> sector read and write.
>>>>
>>>> Regards,
>>>> Mike
>>>>
>>>
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> 
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