[comp.sys.amiga.misc] Copy does a Forbid?

David.Plummer@f70.n140.z1.FIDONET.ORG (David Plummer) (03/18/91)

I aplogize for posting a message that doesn't flame another hardware 
platform in this group.  Please bear with me while I ask an actual 
question.  Maybe a Mac user wil answer me....
 
Anyway, on to the question.  I'm using the ARP Copy command to back up 
and restore my hard drive to a spare hard drive, and in order to speed 
things up, I set the BUF parameter to 2000 (approx 1M).  Now it seems to 
read/write a lot less, but I notice the screen blanker I'm using stops 
dead in between drive activity, as does the mouse pointer if you're 
using it.
 
Does this version of copy (or all copy commands) have to do a forbid 
during the copy to validate the bitmap or something?  Why would s 
standard DOS command shut down multitasking?
 
By the way, does anyone else use FaccII for their hard drives?  Any 
horror stories, or am I safe?
 
- Dave (as above or plummerd@max.cc.uregina.ca)
 



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ig29@terre (Robert Gagnon) (03/21/91)

In article <123.27E5AA36@weyr.FIDONET.ORG> David.Plummer@f70.n140.z1.FIDONET.ORG (David Plummer) writes:
>Anyway, on to the question.  I'm using the ARP Copy command to back up 
>and restore my hard drive to a spare hard drive, and in order to speed 
>things up, I set the BUF parameter to 2000 (approx 1M).  Now it seems to 
>read/write a lot less, but I notice the screen blanker I'm using stops 
>dead in between drive activity, as does the mouse pointer if you're 
>using it.

You probably have a non-DMA Hard Drive controller.  It's the process that
controls the interface that steals all CPU cycles to do its bit pushing.
For example, my TrumpCard (regular) uses a priority 10 controlling process.
Every other process freezes on the system when continuous R/W to the HD
is performed.  Yuk!  Just like a Mac ;)

Robert //
     \X/ Gagnon

David.Plummer@f70.n140.z1.FIDONET.ORG (David Plummer) (03/29/91)

 RG> In article <123.27E5AA36@weyr.FIDONET.ORG> 
 RG> David.Plummer@f70.n140.z1.FIDONET.ORG (David Plummer) writes: 
 RG> >Anyway, on to the question.  I'm using the ARP Copy command to back 
 RG> up  
 RG> >and restore my hard drive to a spare hard drive, and in order to 
 RG> speed  
 RG> >things up, I set the BUF parameter to 2000 (approx 1M).  Now it 
 RG> seems to  
 RG> >read/write a lot less, but I notice the screen blanker I'm using 
 RG> stops  
 RG> >dead in between drive activity, as does the mouse pointer if you're  
 RG> >using it. 
 RG>  
 RG> You probably have a non-DMA Hard Drive controller.  It's the process 
 RG> that 
 RG> controls the interface that steals all CPU cycles to do its bit 
 RG> pushing. 
 RG> For example, my TrumpCard (regular) uses a priority 10 controlling 
 RG> process. 
 RG> Every other process freezes on the system when continuous R/W to the 
 RG> HD 
 RG> is performed.  Yuk!  Just like a Mac ;) 
 RG>  
 
You really have to hate the way quoting wraps text like that....

Actually, I have a A590 (2091) which is (better be!) a DMA controller.  
You may be right to one extent though, since the IORequest Handler gets 
a priority of 11.  The scsi.device gets a priority of 12.  But the input 
device gets a priority of 20, so it still shouldn't lock the system up 
for that second or two.  I still don't know...



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