--- "Andrew, a Mac Freak" <[EMAIL PROTECTED]> wrote: > >Lately I've noticed the cursor jumping around as I attempt to type > in > >Appleworks, Word, iData and Z-write 1.3.1. If I highlight a phrase > and > >attempt to type in new information, the cursor will often stay put > for a > >character or two, then jump somewhere else in the text. If I'm not > watching, > >I can make a real mess of things before I have a chance to undo > the damage. > >I have thrown away the keyboard prefs (along with finder prefs, > for good > >measure) several times without any apparent effect. This is > happening on a > >PTP 250 with plenty of RAM and OS 9.1. Any suggestions? > > > >cwr > > What Mac do you have? Have you tried to replace your > mouse/keyboard > and/or cleaned them? A broken mouse could be the source of the > problem. > -- > -- > Andrew, a Mac Freak
In Windows and Linux, a jumpy, skipping cursor is usually a sign of the wrong driver, not enough memory or an I/O conflict. In Macs if you have a PCI based Mac, a jumpy, skipping cursor is usually an indication that you aren't properly implementing SCSI direct memory access. This is if you have a PCI based Mac. To help prevent the cursor problem you should ensure the following: Your data is aligned on 8-byte block boundaries. Since the DMA hardware can't do odd transfers, it must perform programmed I/O to handle at least part of the transfer if the data isn't aligned. Your physical memory buffer is contiguous (which you ensure by calling LockMemoryContiguous). Otherwise, the DMA transfer will have to be broken up; this will especially be a problem if virtual memory is turned on. Also, if you have disconnects enabled in your device or driver, it's possible that the transfer is getting broken up and some VBL activity is occurring. The bottom line is that you don't want a SCSI disconnect to occur during your transfer. __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
