I'm a little confused. I read that the Apple /// was intended to eventually replace the Apple II line, but allowed limited Apple II+ "emulation" to encourage users to switch, but inhibit further expansion on the platform. Bad move on Apple's part. Now the Apple /// used the 6502B chip, a faster variant of the Apple II's 6502, but still basically the same 8-bit 6502 processor at the heart of the II. So where exactly did the "emulation" come into play?
The hardware, specifically memory control and several other I/O aspects were different on the /// than the II. The emulation code (actually collaboration between hardware and software) conspired to make the machine look, feel, and smell like a 48k II+ with several of the hardware resources marshalled - like the internal drive was mapped to "slot" 6, the serial port was mapped to "slot" 7, and so on, even though the /// only had four physical slots.
It seems to me, the /// ran Apple II software no differently than on an Apple II+. I understand one was required to boot into the Apple II mode, likely very similarly to the way one must boot into Boot Camp in order to run Windows on an Intel Mac. Likewise, not all of the Mac hardware is available to the PC, but otherwise, Windows runs on the Intel chip natively. At least that's how it all looks to me.
That's actually a pretty good assessment.
Now we come to the Apple IIGS. [...] It strikes me as the same thing as Classic under OS X, where the PPC emulates the 68K instructions, but otherwise has access to all of the hardware enhancements the latest technology offers.
I suppose this could be considered emulation, but it is all really handled in hardware. So, not quite the same as the Classic situation.
So, back to my original question: does the Apple /// actually have more in common with a real Apple II than the IIGS which carries the Apple II name?
The /// was closer technologically (and temporally) to the II than the GS, not just down to the instruction set of the CPU.
In other words, if one never used the features of the Apple ///, wouldn't it run identically to an Apple II, right down to the same processor?
Well, yes, but some hardware chicanery is going on to make it appear identical to an Apple II.
Granted at the time, the Apple /// was priced a little high to be little more than an Apple II+, however, it did come with a built-in drive. Otherwise, what was the actual difference?
Big hunks of bank-switched memory. More CPU speed. Flexibility to be both a II and a ///. A numeric keypad.
Cursor control buttons that moved the cursor faster if you pressed them harder. (Seriously.)
Wasn't "emulation" a term that in fact only meant the /// limited the available hardware, thereby emulating the fewer functions of the Apple II+?
I suppose you could look at it that way. It marshalled /// resources in a way that made them appear like a II.
Some thoughts from another forum:
"What's the difference betwee Apple II+.IIGS. IIe, IIc. and ///?"
