Path: utzoo!utgpu!water!watmath!clyde!att!ihnp4!cbmvax!carolyn From: carolyn@cbmvax.UUCP (Carolyn Scheppner CATS) Newsgroups: comp.sys.amiga.tech Subject: Re: Chip RAM Message-ID: <4266@cbmvax.UUCP> Date: 15 Jul 88 00:49:57 GMT References: <3150@polya.Stanford.EDU> <6428@well.UUCP> <2242@sugar.UUCP> <735@applix.UUCP> <11717@agate.BERKELEY.EDU> <2327@antique.UUCP> <737@applix.UUCP> <2333@antique.UUCP> <4790@killer.UUCP> Reply-To: carolyn@cbmvax.UUCP (Carolyn Scheppner CATS) Organization: Commodore Technology, West Chester, PA Lines: 34 In article <4790@killer.UUCP> ltf@killer.UUCP (Lance Franklin) writes: >Speaking of Chip RAM...just out of curiosity, does LoadSeg ever span CHIP and >FAST ram when loading hunks? I.E. if I check the starting address of a >structure to see if it's in CHIP or FAST ram, am I assured that the end of >that structure will also be in the same ram, assuming it's all in the same >chunk (a given, I think). Since CHIP and FAST ram are in separate memlists, you don't have to worry about any loaded segment spanning CHIP and FAST ram. And since a structure must be contiguous memory (else the offsets to its members would not work), you should never have to worry about a structure being split between 2 segments or two allocations. >Oh, another thought...with the possibility, in the future, of machines with >1 meg of CHIP ram, where do I go to find out the actual end of CHIP ram on >any given machine. The Exec MemList (ExecBase->MemList) is an exec List. It's lh_Head is the first MemHeader structure (whose ln_Succ is the next, etc). One of the MemHeaders has the attribute bit for MEMF_CHIP set in its mh_Attributes. That's the CHIP memory MemHeader structure. Its member mh_Upper is the high address (+1) of the last byte. Note that there may actually be a bit more chip ram that this Upper value because the system stack may be at the top of chip ram. See the exec/memory.h include file. -- ========================================================================== Carolyn Scheppner -- CATS Commodore Amiga Technical Support PHONE 215-431-9180 UUCP ...{uunet,allegra,rutgers}!cbmvax!carolyn "Toto, somehow I don't think we're in Kansas anymore" - Dorothy ==========================================================================