esker@abaa.uucp (Lawrence Esker) (08/10/89)
In article <8566@batcomputer.tn.cornell.edu> riley@tcgould.tn.cornell.edu (Daniel S. Riley) writes: <In article <713@abaa.UUCP> esker@abaa.UUCP (Lawrence Esker) writes: <*In article <1388@bnr-fos.UUCP> protcoop@leibniz.uucp () writes: <*>that the Amiga 3000 did not use Commodore's custom chips but used some <*>'off the line' parts by other companies, for example the TI 34000 (?) <*>blitter. Let us further suppose that all of the system software looks ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ <*>the same to the programmer, i.e. all of the function calls are the same. ^^^^^^^^^^^^^^^^^^^^^^^^^^ <*>Would it not be possible for current software to work on both the new <*>hardware and the old hardware? <* ...there are alot of developers <*out there who, for whatever reasons, beleive they can get squeeze better <*performance out of the machine by doing things their own way. Look at how <*much software breaks when there have been operating system changes... <Not every feature of the machine is available in a hardware independent <fashion. Sometimes, a programmer really needs to build a custom COPPER <list, or directly manipulate the blitter registers. There are *legal* <system supported ways to do these things which are manifestly not hardware <independent, and which would break if an "Amiga" were built with <off-the-shelf parts instead of the custom ICs... I stand corrected, sort of. There are a lot of hardware dependent functions supported by the Amiga that would not have existed on a different platform. However, these are all well defined and therefore could be software simulated on the new machine, albiet inefficient. Look at the original premise outlined above. As I said in the second [deleted] part of my post, it is possible, but not practical. Much too much stuff would break for the reasons you gave. <*By the way, you touched on THE reason the Amiga is superior to all other <*computer systems on the market, including UNIX and VAX machines. The common <*programmers interface that operates every feature of the machine in a <*unilateral and upward compatible means. < <Both Unix and VMS have standard programmer interfaces. They couldn't work <otherwise--especially UNIX, which runs on a wide variety of very different <architectures (where VMS only runs on variations on the same basic VAX). I did not mean to say that UNIX and VAX do not have programmer interfaces, of coarse they must, as you outlined. However, their interfaces are for the most primative level. Upper level services, like graphics, animation, universal printer interface (via drivers) and other services just don't exist on the other machines. In UNIX, every programmer ends up with different and inconsistant user interfaces. (I hope X-Windows solves some of this.) In VAX, everything is so deeply buried in documentation and abstract interfaces, that only an expert can get things right. In MessyDOS, the wheel has to be completely re-invented for every application. Ironically, Dan's argument to my first point above provides more evidence to my second point. To quote "There are *legel* system supported ways to do these things that are manifestly not hardware supported." The key words are legal and system supported. This applies to every facet of the Amiga. I believe it to be superior. <In fact, VMS and UNIX are better because memory protection forces you to <use the standard interface--you can't twiddle the bits in the hardware <registers without shifting to a priveleged processor mode. < <-Dan Riley (riley@tcgould.tn.cornell.edu, cornell!batcomputer!riley) <-Wilson Lab, Cornell U. Better from the standpoint of profesional users, security, and muli-user environment. Worst from the standpoint game programming and the more efficient message passing by pointer. Can't please every one... And in all this discussion, we must remember the Amiga is still an infant, or should I say adolescent, compared to its older brothers. With the 68020 with MMU, or the 68030, and virtual memory support and multiple serial ports, it will be unbeatable as an adult. -- ---------- Lawrence W. Esker ---------- Modern Amish: Thou shalt not need any \ * * * ******* / computer that is not IBM compatible. \ * * * * * / \ * * * * * ***** / Sr. Hardware/ASIC Design Engineer \ * * * * * * / Allen-Bradley Communications Div. \ ******* * * ******* / Work: (313)668-2500 Home: (313)973-8561 ----------------------------- Compuserve: 76337,2524 UseNet Smart: esker@abaa.uucp or abaa!esker@itivax.iti.org UseNet Other: __!uunet!mimsy!rutgers!citi!itivax!abaa!esker Nothing left to do but :-) ;-) ;-D