Re: Does having an AppleShare connection active throw off timing a bit?

["Michael J. Mahon" <mjmahon@aol.com>]

On Sep 20, 12:37 pm, sc...@alfter.DIESPAMMERSDIE.us (Scott Alfter)
wrote:
> I thought I had seen something in the past that said that if your IIGS is
> connected to a server, some cycles would get "stolen" here and there, which
> could affect timing-sensitive programs.  Is this the case?  If so, it'd
> explain the weirdness described below:
>
> I've been porting my 1-Wire code from a mix of assembly and BASIC (with the
> former being built with a native assembler) to a mix of assembly and C
> (with both cross-compiled/assembled with cc65).  The Linux box that hosts
> cc65 also has netatalk running on it.  I have a IIGS connected to the home
> LAN through a GatorBox, with my 1-Wire adapter in the 16-pin joystick port.
>
> The assembly-language bits use timing loops to create the 1-Wire signals,
> with delays ranging from 6 μs to 480 μs.  If I'm connected to the file
> server, the reset routine (which checks the 1-Wire bus to see if anything's
> connected) shoots past its window and says nothing's connected.  If I
> comment out that check to get past it, the other routines don't work any
> better.  If I slow down from 8 MHz to 1 MHz and hit Ctrl-Reset, the computer
> disconnects from the server and the 1-Wire routines start working correctly.
> (Interestingly, I can kick the speed back up to 2.8 or 8 MHz and they'll
> still work.  The accesses that the 1-Wire routines make to PB2 (the third
> fire-button input on the joystick port) must slow the machine down to 1 MHz
> for a bit.)

Are you disabling interrupts during your time-sensitive routines?

BTW, I'm surprised that a PB reference slows the machine down.  That's
not like Zip *Chip* behavior at all.  Maybe it's a IIgs thing??

-michael