Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!husc6!bbn!uwmcsd1!ig!agate!ucbvax!decwrl!nsc!voder!apple!dan From: dan@Apple.COM (Dan Allen) Newsgroups: comp.sys.mac.hypercard Subject: Re: Global variables from XCMD/XFCN Message-ID: <12600@apple.Apple.COM> Date: 21 Jun 88 17:55:06 GMT References: <4432@zodiac.UUCP> Reply-To: dan@apple.apple.com.UUCP (Dan Allen) Organization: Apple Computer Inc, Cupertino, CA Lines: 17 In article <4432@zodiac.UUCP> pkahn@ads.com (Phil Kahn) writes: >Problem is, the Language Guide states that XCMD/XFCN cannot use global >variables. Though globals are sloppy, they are sometimes justified. >For example, I want to drive a digitizer board from hypercard. There >is board base address and status information that is best kept global >without explicit reference from hypercard. How can I do this? Or do >I need to pass pointers back to hypercard. Since hypercard wants >strings, I'd have to coerce to string and back to pointer on the next >call. It seems this would only work for pointers to scalars. I can't >see how pointers to records/structs would work from the hypercard side. XCMDs currently do not have their own A5 World, which means that they do not have a jump table (no code segmentation) and they do not have global data. Sorry. Dan Allen Apple Computer