Talk:83Plus:BCALLs:51CA - Revision history

Dan Englender at 18:17, 20 May 2005

2005-05-20T18:17:39Z

FloppusMaximus at 17:49, 20 May 2005

2005-05-20T17:49:28Z

Dan Englender at 07:39, 20 May 2005

2005-05-20T07:39:51Z

Dan Englender at 07:31, 20 May 2005

2005-05-20T07:31:31Z

Dan Englender: Really wacky help hook entry point.

2005-05-20T07:30:44Z

Really wacky help hook entry point.

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So.... I'm a little confused by this entry point. From what I can tell it does the following:
1) Compares the 2nd and 3rd bytes of the the currently loaded help hook with the value 1802h
2) If it matches, it makes a 16bit number out of the 4th and 5th bytes of the currently loaded help hook.
3) It subtracts from 0214h that previously read 16bit value.
4) It returns, restoring all registers other than F.

1802 is jr $+4, which is enough to skip over the value that's being compared to 0214. So it seems like it's checking the help hook for a certain ID. Why, and what installs the help hook that this routine is looking for is a mystery to me though. If anyone has any more info please add.

← Older revision		Revision as of 18:17, 20 May 2005
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	:I haven't looked at the Catalog Help hook at all -- but given that it was written by the same people who wrote the localizers, I wouldn't be at all surprised if it crashed when asked to give help on the new 84+ functions. So perhaps putting this signature in your hook identifies it as 84+-compliant? Note that 14h = 20d; so this could be interpreted as 'this hook is fully compliant with OS 2.20.' [[User:FloppusMaximus\|FloppusMaximus]] 10:49, 20 May 2005 (PDT)		:I haven't looked at the Catalog Help hook at all -- but given that it was written by the same people who wrote the localizers, I wouldn't be at all surprised if it crashed when asked to give help on the new 84+ functions. So perhaps putting this signature in your hook identifies it as 84+-compliant? Note that 14h = 20d; so this could be interpreted as 'this hook is fully compliant with OS 2.20.' [[User:FloppusMaximus\|FloppusMaximus]] 10:49, 20 May 2005 (PDT)
		+
		+	::Good thinking. I looked closer into the OS, and it does in fact use this as a version check. If the hook reports a version of at least 2.20 then it accepts the hook automatically. If not, then it only passes data to the hook if it is pre 2.20 compatible. Guess that means I have to type this up into a real page now... --[[User:Dan Englender\|Dan Englender]] 11:17, 20 May 2005 (PDT)

← Older revision		Revision as of 17:49, 20 May 2005
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	Note: It's not the catalog help app's hook. --[[User:Dan Englender\|Dan Englender]] 00:39, 20 May 2005 (PDT)		Note: It's not the catalog help app's hook. --[[User:Dan Englender\|Dan Englender]] 00:39, 20 May 2005 (PDT)
		+
		+	:I haven't looked at the Catalog Help hook at all -- but given that it was written by the same people who wrote the localizers, I wouldn't be at all surprised if it crashed when asked to give help on the new 84+ functions. So perhaps putting this signature in your hook identifies it as 84+-compliant? Note that 14h = 20d; so this could be interpreted as 'this hook is fully compliant with OS 2.20.' [[User:FloppusMaximus\|FloppusMaximus]] 10:49, 20 May 2005 (PDT)

← Older revision		Revision as of 07:39, 20 May 2005
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	1802 is jr $+4, which is enough to skip over the value that's being compared to 0214. So it seems like it's checking the help hook for a certain ID. Why, and what installs the help hook that this routine is looking for is a mystery to me though. If anyone has any more info please add.		1802 is jr $+4, which is enough to skip over the value that's being compared to 0214. So it seems like it's checking the help hook for a certain ID. Why, and what installs the help hook that this routine is looking for is a mystery to me though. If anyone has any more info please add.

−	(In case it wasn't obvious - this requires 2.30 minimum OS version) --[[User:Dan Englender\|Dan Englender]] 00:31, 20 May 2005 (PDT)	+	(In case it wasn't obvious - this requires 2.30 minimum OS version)
		+
		+	Note: It's not the catalog help app's hook. --[[User:Dan Englender\|Dan Englender]] 00:39, 20 May 2005 (PDT)

← Older revision		Revision as of 07:31, 20 May 2005
Line 6:		Line 6:

	1802 is jr $+4, which is enough to skip over the value that's being compared to 0214. So it seems like it's checking the help hook for a certain ID. Why, and what installs the help hook that this routine is looking for is a mystery to me though. If anyone has any more info please add.		1802 is jr $+4, which is enough to skip over the value that's being compared to 0214. So it seems like it's checking the help hook for a certain ID. Why, and what installs the help hook that this routine is looking for is a mystery to me though. If anyone has any more info please add.
		+
		+	(In case it wasn't obvious - this requires 2.30 minimum OS version) --[[User:Dan Englender\|Dan Englender]] 00:31, 20 May 2005 (PDT)