rick@ut-emx.UUCP (Rick Watson) (02/26/88)
Does anyone remember the extension made to the drive queue entry to allow drives with more than 65536 blocks? It had something to do with putting the high-order bits somewhere else, but I can't remember where. Rick Watson University of Texas Computation Center arpa: ccaw001@utadnx.cc.utexas.edu uucp: ...seismo!ut-sally!ut-emx!rick bitnet: ccaw001@utadnx span: utspan::watson phone: 512/471-8220 471-3241
rick@kimbal.UUCP (Rick Kimball) (03/01/88)
From article <978@ut-emx.UUCP>, by rick@ut-emx.UUCP (Rick Watson): > Does anyone remember the extension made to the drive queue entry > to allow drives with more than 65536 blocks? It had something to do > with putting the high-order bits somewhere else, but I can't remember where. > > Rick Watson From Inside Macintosh Volume IV page 181. Type DrvQEl = RECORD qLink: QElemPtr; { next queue entry } qType: INTEGER; { queue type } dQDrive: INTEGER; { drive number } dQRefNum: INTEGER; { driver reference number } dQFSID: INTEGER; { file-system identifier } dQDrvSz: INTEGER; { number of logical blocks } { on drive } * dQDrvSz2: INTEGER; { additional fields to handle } { large drive size } * I think this is the field you were looking for. -- Rick Kimball Software Design Group Maitland, FL 32751 (305) 660-0006 UUCP: rick@kimbal, ...codas!flnexus!kimbal!rick
ephraim@think.COM (ephraim vishniac) (03/01/88)
In article <978@ut-emx.UUCP> rick@ut-emx.UUCP (Rick Watson) writes: >Does anyone remember the extension made to the drive queue entry >to allow drives with more than 65536 blocks? It had something to do >with putting the high-order bits somewhere else, but I can't remember where. The high-order sixteen bits of the drive size were put in a word following the low-order sixteen bits (that's backwards, by 68000 standards). To distinguish drive queue elements which used this extended format, the queue element type was changed from zero to one. Ephraim Vishniac ephraim@think.com Thinking Machines Corporation / 245 First Street / Cambridge, MA 02142-1214 On two occasions I have been asked, "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?"