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Hi,

Octocontrabass wrote:

Brendan wrote:No; you're making up nonsense to fit your deluded fantasy. The original PC (and all later versions and clones) had the DMA controller chip (and the design depended on it for DRAM refresh) and there was no IRQ sharing.

You said "contemporary" which I took to mean "hardware in wide distribution at the same time as the Amiga IDE".

No, "contemporary" isn't a word I use (too far from "top of vocabulary cache" if that makes sense). You were the one that said it.

Octocontrabass wrote:

Brendan wrote:If there was ever a spec for the software interface for the IDE controller on 80x86 PCs, the first thing it'd say is "primary controller uses IO ports 0x01F0 to 0x01F7"; and the first thing an Amiga programmer would realise is that the exact same software interface is completely and utterly impossible on the Amiga.

The software interface is independent of how the device is mapped. A spec for the IDE controller interface would state that the primary controller is typically mapped using IO ports 0x1f0 to 0x1f7 and 0x3f6 to 0x3f7, but may be mapped elsewhere, and there may be any number of IDE controllers installed.

For IDE? No. For ATA? Possibly, but it's more of a non-standard hack than something I'd expect to find in plausible fiction.

Octocontrabass wrote:The first thing an Amiga programmer would do is look at the Amiga documentation, which helpfully lists both the Amiga IDE mapping and the typical PC IDE mapping side-by-side so the programmer can see it's only mapped to a different address, and not a different software interface.

So, which IO ports does this "not different if you're a troll deliberately ignoring the differences" controller use on Amiga?


Cheers,

Brendan

Brendan wrote:No, "contemporary" isn't a word I use (too far from "top of vocabulary cache" if that makes sense). You were the one that said it.

My mistake, I must have mixed up the quote boxes while I was writing that post.

Brendan wrote:So, which IO ports does this "not different if you're a troll deliberately ignoring the differences" controller use on Amiga?

The default addresses are 0xdd2020, 0xdd2026, 0xdd202a, 0xdd202e, 0xdd2032, 0xdd2036, 0xdd203a, 0xdd203e, 0xdd303a, and 0xdd303e. Since the Amiga has only a single address space, there is no need to specify which one these addresses are in.

Perhaps your complaint is that x86 PCs have two address spaces while Amiga PCs have only one? The software interface doesn't change by just connecting the device to a different address space.