[Coco] CoCoSDC / SDC-DOS file corruption for RS-DOS?

Nick Marentes nickma at optusnet.com.au
Mon Feb 6 15:54:11 EST 2017


On 7/02/2017 5:48 AM, Allen Huffman wrote:
>> On Feb 6, 2017, at 1:00 PM, Nick Marentes <nickma at optusnet.com.au> wrote:
>>
>> I have. Are you running in double clock speed? The SDC can corrupt when writing in double clock speed.... just like a real disk controller to floppies.
>
> Wow. That truly IS real emulation.
>
> I do not recall if I used the high speed POKE in my program, since it wasn't doing anything that needed speed (just disk I/O), but I very well may have due to force-of-habit, forgetting all about the need for patches to support double speed disk access.
>
> I'll check. Thanks, Nick!
>
> Do the patch programs for RS-DOS work on SDC-DOS? I used to use DFIX.EXE (I think that was a Steve Bjork one) that would patch for 6ms and high speed and all that. I'll have to find it and give it a try.
>
> (And, for the fun of it, he also wrote a cool caching RAM disk that would copy all writes to the RAM image of the floppy. When you did a read, it came back instantly. Any future writes went to RAM and disk. I used to use it all the time. It would make the drive lights blink back and forth, and it could detect if you pulled a disk out and would know to reset the cache somehow. Good stuff.)
>
> 		-- Allen
>

Maybe this could be a suggestion to Darren for the next version of the 
SDC-DOS?

Make it work at double clock without corrupting files.

I see this as an important update. I've lost count how many files it's 
corrupted because I forget to revert to slow clock before saving. That's 
why I keep multiple DSK versions when developing.

Nick




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