consult@aucs.UUCP (02/14/87)
Sender:John Baikie
I'm writing this to see if any can tell me about the Apple //gs
and what is involved in upgrading an Apple //e to one.
Thanks
John Baikie ag0@k.cc.purdue.edu.UUCP (02/16/87)
In article <273@aucs.UUCP> consult@aucs.UUCP (John Baikie) writes: >Sender:John Baikie > > I'm writing this to see if any can tell me about the Apple //gs >and what is involved in upgrading an Apple //e to one. > John Baikie I have looked into the upgrade situation for the //e and I have come to the conclusion that it is not worth it. The upgrade (which is not available just yet- I think) costs $499. There may be a rebate of ~$100. The upgrade includes a new mother board and pan (the underside of the computer). The upgrade does NOT include a new keyboard, mouse, numeric keypad, or 3.5 inch drive. In order to totally upgrade your //e, these additional parts will probably run you up to $500+ more. On top of all that, Apple will keep the mother board from your old //e. If you had any cards that fit into the auxilliary slot of your //e you will not be able to use them on your upgraded "//gs". Many of your comunications programs will not work. I have read (although I am not entirely sure it is true) that accelerator cards will not work in the //gs. Some say that is not a problem because a //gs runs at 2.8 times the speed of the old apple, however *MY* Speedemon runs 3.5 times faster so you do lose some speed there. The bottom line is that in order to upgrade completely you will more than likely spend a good $1000.00, plus lose your //e, and be forced to shelve or sell many of your cards and programs. Since a complete //gs system retails for under $1000.00 you are better off just buying one out right and hanging on to (or selling) your current system. Perhaps some company will come out with a way to use a //e as a slave for a //gs and we will be able to "merge" the two systems to form a more powerful one (unlikely, but hey, this *IS* America!!). Frankly I am dissapointed in Apple. They are ripping us off incredibly-- especially since they keep our old mother boards. Perhaps they expect us to recoup losses by selling our "useless" cards. I don't think the market for the old cards is going to be so good anymore- especially since they are second hand. If you are really wanting to upgrade to a more powerful system, I think it would be worth your time for a few dollars more to look into some alternatives to Apple. The //gs has a lot of nice features, but it is not really state of the art (except for its sound capabilities). With today's technology and software advances, I don't see any reason for micros not to run REAL multitasking operating systems with true memory management and even virtual memory running at reasonable speeds. All these things are possible today. Why the (hobby) microcomputer industry has not caught up with the times yet is beyond me. Probably economic reasons. Personally, I love my little Apple, and I think I want to keep it just the way it is. When I feel the need to upgrade, I will buy a system that won't be outdated before I get it out of the box. Colin PS Does the //gs support multitasking??
hansen@cs.uiowa.edu.UUCP (02/25/87)
In regard to multitasking: I have looked into the problem from the micro and mini computer side of things and have come to the conclusion that for true multitasking you absolutely must have hardware protection between processes. If you don't have this, then a bug in your printer spooler crashes your editor, your neat alarm clock, your operating system master program, etc. No process has any protection from any of the others. The system is really too complex already for reliability. The attempt at running n processes at the same time without hardware protection produces n! as many opportunities for interacting bugs. The end result is that you simply can't come up with a working machine, or at least working software that is acceptable to the majority (I realize that a subset of users will be happy with this shortcoming, but even this group will become convinced the first time a bug in the computer they're down loading from in the background destroys an hour's work in the editor they wer e using in the foreground.) Thus the reason current micros don't have true multitasking is that they don't have hardware process protection. The 68000 doesn't have it, although the 68010 and 68020 do. The 6502 certainly doesn't, and thus the //gs in order to be at least reasonably compatible, doesn't either. Kurt
ralphw@ius2.cs.cmu.edu.UUCP (03/03/87)
In article <8702251007.aa07502@SPARK.BRL.ARPA> hansen@cs.uiowa.edu (Kurt Hansen) writes: >In regard to multitasking: > >I have looked into the problem from the micro and mini computer side of things >and have come to the conclusion that for true multitasking you absolutely must >have hardware protection between processes. Not strictly true, as long as you are wiling to discipline yourself and use reserve some of the capabilities of the processor or associated hardware. For example, OS-9 level 1 for the Radio Shack Color Computer (based on the Motorola 6809) is a multitasking system. >.. the reason current micros don't have true multitasking is that they don't >have hardware process protection. The 68000 doesn't have it, although the >68010 and 68020 do. The 6502 certainly doesn't, and thus the //gs in order >to be at least reasonably compatible, doesn't either. The Apple //e architecture supports bank-switching, so it is not normally possible to play with somebody else's program if it's in the other bank. So a naive form of multitasking would involve setting up a timer interrupt (say, every 60 seconds) and switching between programs in each bank. [This would be most useful with the larger bank-switched cards like the Applied Engineering or Checkmate Cards.] The trick is knowing when to switch banks without leaving the machine in an inconsistent state. If a user program tries to switch this it could wedge the machine, so Apple recommends that you don't do it. For the 65816, it will be more useful to use the segment capability to provide some limited protection. This is what allows the Minix operating system (a multitasking operating system developed by Andy Tanenbaum) to run on an IBM PC with NO hardware process protection. -- - Ralph W. Hyre, Jr. Internet: ralphw@ius2.cs.cmu.edu Phone:(412)268-{2847,3275} CMU-{BUGS,DARK} Amateur Radio: N3FGW (c/o W3VC, CMU Radio Club, Pittsburgh, PA) (was KA3PLY, will probably change calls again if/when I get Advanced.)