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Start Manager Q&As

Technote OS 520 December 1992

Revised by: Developer Support Center September 1993
Written by: Developer Support Center December 1992

This Technical Note contains a collection of archived Q&As relating to a specific topic--questions sent the Developer Support Center (DSC) along with answers from the DSC engineers. Current Q&A's can be found on the Macintosh Technical Q&A's web site.

SetTimeout refers to device specified by SetDefaultStartup

Date Written: 4/2/91

Last reviewed: 6/14/93

SetTimeout lets you specify the number of seconds the system will wait for the internal hard disk to respond (Inside Macintosh, oluVolume V, page 356). Is this only for a SCSI device at ID=0 or is this the device specified by the SetDefaultStartup call? Can I assume that SetTimeout and SetDefaultStartup are supported if the machine type returned by SysEnvirons is greater than a Macintosh Plus? Is there a better way to determine if these calls are supported?

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SetTimeOut is for the internal device, whose ID must be zero.

Growable Macintosh system heap does not affect startup process

Date Written: 9/17/90

Last reviewed: 6/14/93

Now that the system heap is growable, what are the new restrictions on the installation and booting that must be observed to ensure that the specs of a 2 MB Macintosh can be met with no perceived performance impairment?

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Changes to the startup process have little or no effect on the system heap size issues. The system heap was already growable during patch installation on most of Apple's machines. The change was to make the growing work the same way on the Macintosh Plus and SE as on all the other machines. There are no new implications for system heap size, except that Apple can remove the code in the patches that grow the system heap explicitly (previously needed for the Plus and SE), because all Apple machines now have the automatic growing code active during patch loading. Note that the system heap continues to grow while 'INIT' resources from the system file and from extensions are loaded, and while applications are run (thanks to code from the Process Manager).

Macintosh GetTimeout and SetTimeout documentation fix

Date Written: 5/3/89

Last reviewed: 11/21/90

GetTimeout and SetTimeout aren't working as documented. What's wrong?

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The Inside Macintosh Volume V documentation for the obscure routines GetTimeout and SetTimeout is wrong. The routine selector for InternalWait is passed in A0, NOT on the stack. The assembler macros and Pascal and C "glue" routines for MPW 2.0 based on this information are also incorrect.

The problem was fixed in MPW 3.0. The following macros are defined in Traps.a for MPW 3.0:

MACRO
_GetTimeOut
MOVEA.W #0,A0
_InternalWait
ENDM

MACRO
_SetTimeOut
MOVEA.W #1,A0
_InternalWait
ENDM

The return value from GetTimeOut is in D0.

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