Re: Multitasking apple II

[Roger Johnstone <rojaws@orcon.net.nz>]

In <20040917152504.17374.00000785@mb-m27.aol.com> Michael J. Mahon wrote:
> Roy wrote:
> 
>>Softswitch by Roger Williams did this on a IIgs.
> 
> But did anyone do it on a //e with a RamWorks-type
> or a "slinky"-type card?

It could be done. You would have to trap the reset interrupt vector, 
since this is the only interrupt a stock Apple II can generate from the 
keyboard. Then you would need a safe place in main memory to hold a 
small program that would switch banks, or at least switch to another 
bank with the main switching program in it.

The two problems are that most programs trap the interrupt vector 
themselves and there is no such thing as safe memory on an Apple II ;o) 
I understand Softswitch uses a classic desk accessory which solves both 
problems.

A simple hardware card like the copy cards that had an interrupt button 
on them would make things a lot easier.

-- 
Roger Johnstone, Invercargill, New Zealand
http://vintageware.orcon.net.nz/
________________________________________________________________________
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