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2

Light pens (Gibsen light pens for example) also need video sync so used slot 7.


4

Looking over the Apple II expansion card pinout, it seems it's largely just the pins of the 6502 plus some +12V supplies and such. Yes, and no. The unique point about the Apple II bus is that basic address decoding is done externally to the card. This saves quite some circuitry. Generally speaking, though, is there any reason any other 6502 machine, ...


1

I believe the major factors, besides just the electrical characteristics of the bus, are: Standardization of access to each slot, such that each is guaranteed certain resources that cannot conflict with other slots/cards. This is something the Apple ][ provided, and 6502 systems without slots didn't. Built-in and aftermarket software support that is ...


2

Figured it out. I consulted the now-expired patent (US4601018) on the RAMWorks, which indicates that the card has the bank select register at not only C073, but C071, C075, and C077 as well. Changing my card to respond to these four addresses solved the problem with ProTERM, and the AE stuff still works as well. So evidently some applications are using these ...


4

I am restoring a couple of Apple II machines. I would like to add an external 3.5" floppy drive, but they are prohibitively expensive. Well, you're in for an even higher price tag, as you would need either need an Apple II 3.5 SuperDisk Controller (Apple Part number: A0076LL) Blue Disk Controller While the first gives you compatibility with most Apple ...


1

It's the same floppy drive, but you need a different controller card. The Apple 5.25" floppy implemented the controller largely in software---that was the big Woz invention, while the IBM PC 5.25" was implemented largely in hardware. You could probably build your own controller if you can find the schematics. But you're better off trying to find one on eBay,...


7

The question seams to be based on the assumption that the Atari 800 slots are somehow not 'real' slots. Similar it implies that the mentioned "70's FCC regulations" were some kind of incredible strict. But the Atari slots do carry everything needed for expansion. And making a system to fit FCC Part 15 regulation wasn't some dark art, but could be rather ...


4

Per Apple IIc ROM Versions: Memory Expansion IIc (ROM version 3) ... The new motherboard added a 34-pin socket for plugging in memory cards irectly, which allowed for the addressing of up to 1 megabyte of memory using Slinky-type memory cards. ... So you're correct that the expansion cards are Slinky-style. Following up on that, I also found a ...


2

The official way to access either RAM is due the so called 'Protocol Converter'. A call convention, introduced with the IIc disk port. The IIc disk port was the first enabled to hanabled to handle multiple peripherals over one bus. Protocol Converter interface is much like Prodos' MLI and allows to access block or character devices in an abstract way. At ...


3

Some auxiliary RAM cards put the bank select register anywhere in the range C070-C07F. In general this interferes with analogue input reset since original II times. But on the IIe (and IIc) as well with IOU management (Double-HiRes), as they use $C07E/7F and $C077/78 (only IIc). $C074 was as well reserved by Applied Engineering for the Transwarp - after all,...


2

The Apple Super Serial card did come with a metal back plate for the DB25 connector, which was clamped to the interior conductive coating on the plastic cases of later revisions of the Apple II+ and the Apple IIe. IIRC, circa 1981, the Apple II+ with Disk drives and a Super Serial Card plugged in was tested for compliance with FCC Part 15 RFI/EMI ...


6

Why was Apple unable to comply with the limits when e.g. Atari managed it? Purely through engineering that Apple was unwilling to carry out. I have added a relatively detailed explanation of this to the Atari 8-bit article on the wikipedia. The long-and-short is that it wasn't the slots themselves that were the problem, but providing some sort of ...


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