On Wed, 28 Feb 101 g.baltissen@hccnet.nl wrote: > > ... or in my case, programmable interrupt controller. > > The 8259. > > > In order ot properly support ISA devices, I feel the whole ISA DMA and IRQ > > system should be implemented. > > I agree. But using the 8259 for this purpose? In 1988 I had ny reasons NOT > to use it. I will study the datasheets again to see why. Please do. :) I"m curious about your concerns. > > > However, I dont believe I'd hook NMI up. > > Why not? It certainly won't harm. And don't fall in the same trap the > designers of the CP/M-cart for the C64 did: they didn't "need" NMI and IRQ > either. Later they regretted that very much. Correct me if I"m wrong, but the ISA bus's only NMI line, per se, is the parity error line. Since the c64 wont be generating parity (anyone got a parity gen circuit?), I feel it's best to leave it unhooked so the poor thing doesnt get an NMI on every bus access. ;) > > Groetjes, Ruud > > http://Ruud.C64.org/ > > > > - > This message was sent through the cbm-hackers mailing list. > To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi. > - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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