[Coco] Megaread problems

[Stephen H. Fischer]

FYI I wrote a program to create big files. It is called Filldisk and is in SHF888.dsk (zip) on my webpage.

http://home.mindspring.com/~sfischer1/ 

The source is online elsewhere. PM me if interested.

SHF

----- Original Message ----- 
From: "Dave Philipsen" <dave at davebiz.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Monday, March 27, 2017 11:15 AM
Subject: Re: [Coco] Megaread problems


> Just a note.  I'm not sure if I found a bug in NitrOS9 'copy' or not. 
> But just for snicks I tried something. I have an 8MB ramdisk named '/R0' 
> and I have a 128MB SD card partition named '/SD0'. There is plenty of 
> free space on '/SD0'.  So I tried as below to 'copy /R0@ 
> /SD0/ramdisk-image'.  This should copy the entire ramdisk to an image 
> file on the SD card.  The copy basically worked but it locked up the 
> shell I was in even after the file was supposedly written (which 
> shouldn't have taken much more than 30 seconds).  I hit 'BREAK' and 
> finally regained the shell but the copy process was still running.  I 
> killed it and 'procs' showed it was gone but the system was still being 
> bogged down with something.  I had to re-boot NitrOS9 to clear it.  When 
> I did a 'dir -e' of /SD0 I found the huge file in the directory and it 
> was the correct size (80 0000) but its attributes were null (--------) 
> and the owner was '8000'.  When I tried to delete the file I got a 214 
> error so I used ded and found the first sector of the file and manually 
> corrected the attributes and the owner so that when I did a 'dir' the 
> owner showed as '0' and the attributes showed as '--ewrewr' ($3F) and 
> then I was able to delete it. At first glance the filesystem on my SD 
> card is ok but I have't checked it all thoroughly yet.  Maybe I just 
> didn't allow enough time for the copy to finish.  Has anyone ever run 
> into such a problem before?  Has anyone ever manipulated files as large 
> as 8MB under NitrOS9?  I did create a file of slightly over 1MB in size 
> and everything seemed to be ok.
> 
> I'm going to format another SD card and play around a bit and see if I 
> can re-create the problem and find out exactly what it is.
> 
> 
> Dave
> 
> On 3/27/2017 12:44 PM, Dave Philipsen wrote:
>> I guess the problem has to do with the fact that the reference to 
>> '/DD' is just a reference to the root directory.  If you use '/DD@' 
>> then you will be referencing the raw device. Alternatively, you could 
>> create a file that is at least as large as the desired megaread and us 
>> it like this:  'megaread </dd/bigfile'.
>>
>> The error #214 is normal for trying to open/read a directory.  For 
>> instance, try 'copy /dd mydir'.  You'll get the same error.  You 
>> could, however, 'copy /DD@ mydir' in which case you'd need to make 
>> sure that the device which will hold 'mydir' is larger than the 'DD' 
>> device itself.
>>
>> Dave
>>
>>
>> On 3/27/2017 7:35 AM, Robert Gault wrote:
>>> Something very strange is going on with the version of megaread in 
>>> the current NitrOS-9 builds. The program works correctly for Dave 
>>> Philipsen and possibly everyone else. It fails for me on any system I 
>>> try.
>>>
>>> megaread 1 </DD
>>>
>>> The above should run the program for the minimum number of reads with 
>>> standard input changed to /DD. For MESS, VCC, and a 512K Coco3 the 
>>> result is error #214.
>>>
>>> megaread </DD
>>> Same error as above for the default 1024 repeats.
>>>
>>> The crc for the version under test is $A5A49C, size $7A which is 
>>> identical with the nightly build version. Attr for tested drives 
>>> indicates normal values.
>>>
>>> Robert