• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Search results

  1. Snial

    Aaah, so A/UX didn't have the 24-bit mode issue?

    Aaah, so A/UX didn't have the 24-bit mode issue?
  2. Snial

    Word access odd Address Exceptions on 68K software - were they ever used?

    There's two signals, UPA<1:0> which can be programmed by the MMU. Yes, so it all adds up. Each Page Descriptor has a U<1:0> pair of bits which can get sent out to the signals UPA<1:0>. The table descriptors themselves, don't have these bits, so if I understand it correctly (which I...
  3. Snial

    Word access odd Address Exceptions on 68K software - were they ever used?

    Aaah, I assumed the '040 was the same as the '030. I'll look up the '040 on bitsavers. Started to do that - so maybe given that System 7 only came out in 1991, they already made it '040 compatible? Do you know what the Apple VM page table structure was then? Do you have a link to that info? It's...
  4. Snial

    Katheryn's Conquests!

    Cool! PS. Dear admin, it'd be really nice just to be able to have a reaction field so we can just 'like' posts or whatever, like we can for status updates!
  5. Snial

    Word access odd Address Exceptions on 68K software - were they ever used?

    Aaah, well this comment has lead me to look into the 68K MMU in more detail, specifically the 68030 MMU. It's fiendishly more complex than the M88K's MMU! As we've seen, the M88200 has a fixed, two-level table, but the 68030 has up to 4 levels + FC table entries! So, from page 9-54 of the 68030...
  6. Snial

    Word access odd Address Exceptions on 68K software - were they ever used?

    The odd address exception for data fetches won't happen for the 68020 or later. "The 68020 has no alignment restrictions on data access" https://en.wikipedia.org/wiki/Motorola_68020 I've just been reading a bit about exceptions on the M88K user manual (I'll come to PowerPC next) and found that...
  7. Snial

    Emulation: Infinite Mac

    @mihai, @joevt - actually just trying to restart the 6100 causes the hang, it's not specific to trying to reboot into VM. It happens even if there's no infinite HD, just a boot drive too.
  8. Snial

    Word access odd Address Exceptions on 68K software - were they ever used?

    Hi folks, I think I'll add a bunch of replies here: Apple also didn't seem to use the TRAP instruction exceptions either, but they are useful. Examples: 1. I hooked a TRAP exception to force a jump into the Mac Plus ROM debugger when I was debugging MiniMorse using MacAsm...
  9. Snial

    Emulation: Infinite Mac

    I can certainly run System 1.0 on a Mac 128kB today: And 1.1, 2.0 and 2.1 (which says Finder 5.0):
  10. Snial

    Emulation: Infinite Mac

    Hi @jeovt! Sorry about the lack of a reply until now. I wouldn't know how to reboot the PM6100 on CD in VM mode, but using the HD for swap. I always assumed swap was on the boot drive. Oh, of course, there's a drop-down in the memory panel to choose it, but I never thought about that. So...
  11. Snial

    Word access odd Address Exceptions on 68K software - were they ever used?

    A 68000 CPU will generate an Address Exception if there's an attempt to read a word (or long) from an odd address. Was that feature ever used (apart from to trap errors)? I'm asking, because I believe that odd addresses were used on some Amiga software to implement dynamic libraries. If you load...
  12. Snial

    Bit confused, I guess the second picture is "after", but I thought sunlight would make it go...

    Bit confused, I guess the second picture is "after", but I thought sunlight would make it go yellow? The ultimate solution is to move to cloudy, rainy country, just like we Brits have... my Mac Plus looks nearly as beige as it ever was (not a platinum Plus I believe) ;-) .
  13. Snial

    small ide HD

    Good point. You'd need an adapter, I can see they can cost as little as £4 on eBay (+P&P); and small CF cards can be bought for about £5-£6; whereas a 512MB DOM from eBay would be about the same (£10 inc P&P).
  14. Snial

    small ide HD

    Brilliant! I was trying to think of a good DOM joke, but this one is inDOMitable ;-) !
  15. Snial

    small ide HD

    Until a few hours ago I'd never heard of a DOM and now they're all the rage!
  16. Snial

    PowerBook 1400 series ROM and RAM tidbits

    Curious. My PB1400c/166 (sorry old bean), has 56MB from 8MB Mobo RAM + 8MB System RAM + 16MB +24MB user RAM modules. So, I can't really prove or fix that issue (I do have another 8MB System RAM module and there are 4 spaces for RAM on my 24MB module, or maybe the 16MB one. But I don't know if...
  17. Snial

    A stack of Macs & in the fore, a PB1400! Meanwhile, a kettle I spy, to provide the essential...

    A stack of Macs & in the fore, a PB1400! Meanwhile, a kettle I spy, to provide the essential, constant coffee resupply :cool:
  18. Snial

    Fantasy M88100 Macs

    It might have been. From the Gary Davidian's oral transcript: ".. in parallel, the development of the-- what we call the RLC was going on. It was a RISC version of the Macintosh LC and it had an 88100 CPU and two 88200 cache MMUs. And I was able to develop the emulator for that, that ran the...
  19. Snial

    Obviously, 30 minutes of 11kHz, 8-bit PCM audio of course :-D ! That's nearly a whole album!

    Obviously, 30 minutes of 11kHz, 8-bit PCM audio of course :-D ! That's nearly a whole album!
  20. Snial

    Fantasy M88100 Macs

    Continuing the analysis of NuMac graphics performance, I found the proper article I linked to via MacTech. In fact it's a Develop article from June 1994 and is still hosted on VintageApple.org, but as a PDF so the images are retained...
Top