Talk:83Plus:BCALLs:80AB - Revision history

AndyJ at 14:53, 15 August 2007

2007-08-15T14:53:36Z

FloppusMaximus: /* Finding an app's name */

2007-08-15T01:23:50Z

‎Finding an app's name

AndyJ: Finding an app's name

2007-08-14T22:15:41Z

Finding an app's name

New page

== Finding an app's name ==

One, the page states "NZ set if not found". That is ... confusing, to say the least. Does it mean Z is reset if not found, or something else?

Two, it took me some experimenting to figure out how to find an app's name. The examples are somewhat misleading as to what values you provide when searching an app. Here's the code I use to find an app's name given its basepage:

<pre>
; a is the app's basepage
push af
ld hl,$4000
ld de,$8040 ; app name field
bcall(_FindOSHeaderSubField)
; technically the name could not be found but that will not happen
pop af
; a:hl points to the name
</pre>
[[User:AndyJ|Andy Janata]] 15:15, 14 August 2007 (PDT)

@@ Line 10: / Line 10: @@
    ld hl,$4000
    ld de,$8040			; app name field
-   bcall(_FindOSHeaderSubField)
+   bcall(_FindAppHeaderSubField)
    ; technically the name could not be found but that will not happen
    pop af
@@ Line 20: / Line 20: @@
 :Incidentally, yes, I would say it's safe to assume that every app has a name.  And it's probably safe to use this routine (or FindOSHeaderSubField) to search app headers, because that's what the OS does, but it's not 100% foolproof in the case that the field you're looking for doesn't exist.  This is because it doesn't actually stop at the program image field -- rather, when it gets to that field, it skips 70h bytes (because of the bug in [[83Plus:BCALLs:805A|GetFieldSize]]) and continues on its way.
 :[[User:FloppusMaximus|FloppusMaximus]] 18:23, 14 August 2007 (PDT)

← Older revision		Revision as of 01:23, 15 August 2007
Line 16:		Line 16:
	</pre>		</pre>
	[[User:AndyJ\|Andy Janata]] 15:15, 14 August 2007 (PDT)		[[User:AndyJ\|Andy Janata]] 15:15, 14 August 2007 (PDT)
		+
		+	:Yeah, I don't know what I was thinking when I said 8000 for the address. Sorry about that. As for Z/NZ... yeah, maybe better notation is in order. By "NZ is set" I mean that the zero flag is cleared; thus, the NZ condition is true. Most if not all of the field search routines will return with the zero flag set (Z) if they find the given field, or cleared (NZ) if they don't.
		+	:Incidentally, yes, I would say it's safe to assume that every app has a name. And it's probably safe to use this routine (or FindOSHeaderSubField) to search app headers, because that's what the OS does, but it's not 100% foolproof in the case that the field you're looking for doesn't exist. This is because it doesn't actually stop at the program image field -- rather, when it gets to that field, it skips 70h bytes (because of the bug in [[83Plus:BCALLs:805A\|GetFieldSize]]) and continues on its way.
		+	:[[User:FloppusMaximus\|FloppusMaximus]] 18:23, 14 August 2007 (PDT)