Advanced Hack Usage
Some of you astute folks might have noticed a potential issue when running hacks. What happens if two hacks try to hook into the same system routine? Actually, it's exactly this situation which makes extensions managers necessary. When multiple hacks try to hook into the same routine, the manager chains them together like a bucket brigade, with each hack passing on parameters to the next one in the chain. This keeps the hacks in harmony, with only the last one calling the original system routine directly.

While usually a nifty solution, this can sometimes cause problems if the order of the hacks in the chain is significant. For instance, if one of the hacks is a replacement hack, it must be the last one in the chain because it won't call any hacks following it in the queue. This happens when trying to run FindHack with TealMagnify, the software magnifying glass. Both hook into the system "Find" command. TealMagnify brings up a magnifying window when you tap on the silkscreened "find" button. It also has another "find" button inside its window to allow "passing through" for an actual search operation. In normal use, this allows the silkscreened button to be used for two purposes: to start the magnifying glass, or perform a search operation. When using FindHack and TealMagnify together, TealMagnify must be first in the list because FindHack does not have a "pass-through" button. It wouldn't make sense for it to have one, as you'd normally never want to perform a standard system search if FindHack's enhanced search is available.

Conflicts between hacks or between a hack and an application can also occur. Sometimes, this is due to limited resources shared between the two parties. Other times, a conflict arises because two hacks are trying to accomplish tasks which are mutually exclusive. In either case, fixing the problem, if it is even possible, often requires modification of the programs. Fortunately, TealMaster has exclusive tools to avoid both problems. For hack-order problems, its priority setting allows the order of hacks to be specified explicitly. For conflicts, its application profile mapping feature allows hacks to be automatically turned on and off depending on the current application. By turning off hacks that are not needed, chances of encountering a conflict are minimized.

The major cause of hack conflicts, however, is exhaustion of stack memory. As converted in Issue #2, stack memory is a special section of all available memory reserved by Palm OS. All hacks must share this "stack" with each other and the current application. When the available stack runs out, the result is typically a spectacular system crash. The program TealMemBrain can be used to prevent such problems. A hack itself, TealMemBrain can be set to allocate more memory to the stack, increasing stability and preventing stack-based problems.

Where to Find Hacks
Hacks can be found on all Palm OS software download web sites. Handango and PalmGear H.Q. list some 300 of these system extensions. Some of the programs mentioned in this article were:

TealMaster ($9.95, www.tealpoint.com/softmstr.htm)
TealEcho ($11.95, www.tealpoint.com/softecho.htm)
TealLaunch ($11.95, www.tealpoint.com/softlnch.htm)
TealGlance ($11.95, www.tealpoint.com/softglnc.htm)
TealMagnify ($11.95, www.tealpoint.com/softlens.htm)
TealMemBrain ($11.95, www.tealpoint.com/softmemb.htm)
FindHack ($10, www.perso.wandoo.fr/fpillet/)
Afterburner (freeware, www.gavini.com)
printHack (prerelease, www.paulcomputing.com)

@Teal Mobile
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