rs54@cunixf.cc.columbia.edu (Richard Sucgang) (05/19/91)
I am unsure about this but: Is it possible to write a program so coded that it will specifically run only with a 68000 chip, and not t on any of the later generation chips? I suppose Motorola has built in early generation emulators, but I am unsure. -rich Richard Sucgang : Dept. of Anatomy and Cell Biology Columbia University (sucgang@cuhhca.hhmi.columbia.edu; de slime god rs54@cunixf.cc.columbia.edu)
sjhg9320@uxa.cso.uiuc.edu (Maximum Slackness ) (05/19/91)
rs54@cunixf.cc.columbia.edu (Richard Sucgang) writes: >I am unsure about this but: >Is it possible to write a program so coded that it >will specifically run only with a 68000 chip, and not t >on any of the later generation chips? The instruction sets for the MC68XXX series are pretty much entirely forward compatible, but you can always tell which chip you're using by checking the Status Registers or, if you're running under the Mac OS, by making a quick call to SysEnvirons (Pre-System 7) or Gestalt. Once you've checked which chips are there, just exit to shell if you've returned a result you don't want. Any chance you're doing this to support an emulator? -- ______________________________________________________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
es1@cunixb.cc.columbia.edu (Ethan Solomita) (05/19/91)
In article <1991May18.190505.21579@ux1.cso.uiuc.edu> sjhg9320@uxa.cso.uiuc.edu (Maximum Slackness ) writes: >rs54@cunixf.cc.columbia.edu (Richard Sucgang) writes: > >>I am unsure about this but: >>Is it possible to write a program so coded that it >>will specifically run only with a 68000 chip, and not t >>on any of the later generation chips? > >The instruction sets for the MC68XXX series are pretty much entirely >forward compatible, but you can always tell which chip you're using >by checking the Status Registers or, if you're running under the Mac OS, >by making a quick call to SysEnvirons (Pre-System 7) or Gestalt. >Once you've checked which chips are there, just exit to shell if you've >returned a result you don't want. > >Any chance you're doing this to support an emulator? >-- >______________________________________________________________________________ >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I can't quite fathom WHY he would want to do this, but all the emulators I know of support 030s just fine. -- Ethan The constitution isn't perfect, but it's better than what we have now.
blm@6sceng.UUCP (Brian Matthews) (05/20/91)
In article <1991May18.180250.20204@cunixf.cc.columbia.edu> rs54@cunixf.cc.columbia.edu (Richard Sucgang) writes: |I am unsure about this but: |Is it possible to write a program so coded that it |will specifically run only with a 68000 chip, and not t |on any of the later generation chips? data values: byte 0, 1 text moveq &1, %d0 lea values - 1, %a0 long 0x10300200 ; mov.b 0(%a0,%d0.w*2),%d0 At this point, d0 contains 1 on a 68020 or higher, and 0 on a 68010 or lower. I'll leave it up to the reader to figure out why this works (look at how the scale factor is encoded on 020s). If you're doing this on a Mac, you can use SysEnvirons to find out what kind of processor you're running on. -- Brian L. Matthews blm@6sceng.UUCP
rs54@cunixf.cc.columbia.edu (Richard Sucgang) (05/20/91)
To those of you who wonder about the question on the 68000 specific instructions...it isn't because *I* want to write the program...I someone explained to me that an old game of his won't run on the newer machines, giving a message that it requires the old 68000 chip. Sort of didn't make sense...I suspected the ROMs or System... -rich Richard Sucgang : Dept. of Anatomy and Cell Biology Columbia University (sucgang@cuhhca.hhmi.columbia.edu; de slime god rs54@cunixf.cc.columbia.edu)
sjhg9320@uxa.cso.uiuc.edu (Idiot Savant ) (05/20/91)
rs54@cunixf.cc.columbia.edu (Richard Sucgang) writes: >To those of you who wonder about the question on the 68000 specific >instructions...it isn't because *I* want to write the program...I >someone explained to me that an old game of his won't run on the newer >machines, giving a message that it requires the old 68000 chip. >Sort of didn't make sense...I suspected the ROMs or System... Usually its the Sound Manager Stuff or an absolute requirement for specific memory addresses being free that seems to hang up all the games I loved on the SE and had to dump when I upgraded to a IIci. (Reach for the Stars, The Ancient Art of War, Dark Castle...) -- ______________________________________________________________________________ Internet: scott@scotty.life.uiuc.edu AppleLink: ISware ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~