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I can't help but wonder if the Lisa used system memory for video refresh because it was gospel at Apple because, you know, it was the Apple II's special sauce. (Apple's corporate culture of the time was really into doubling down on their internal ideas and "special-ness". Poster child: Twiggy.)...

Yeah, I assumed the NetBook usage was the original source of Trash's confusion. But certainly today outside of anything but a laptop context a "percent" is almost certainly going to mean key count. It seems like if you're browsing, say, Amazon listings "80%" and "TKL" are sometimes used...

... Ugh! Yeah, so I dug up that hardware reference for the Apple Lisa, and discovered my assumption that it used separate video RAM was completely off-base, it does indeed do DMA to system memory for video refresh. So, yeah, I guess retract my objection about it should be faster when the CPU...

You will sometimes see percentages thrown out in relation to "small" keyboards; for instance, when NetBooks were a thing you'd see their keyboards being described as "92%" or "87%", often in combination with the word "pitch". In this case the percentage would often refer only to a single...

That would be a pretty goofy oversight; even crude econoboxes like a TRS-80 Model 3 gate a wait state generator on the video address decoder.

Just to be clear on something: Doesn't "60% keyboard" generally refer to a keyboard that has a reduced number of keys, IE, like one of those (hateful in my opinion but I know some people love them) "Happy Hacker" keyboards that were a fad 20 years ago? IE, something like this? *Not* like what...

Typically when a machine has separate video memory you don't wait-state the CPU unless it's specifically accessing video memory during the middle of a refresh cycle. Are you saying the Lisa runs "slow" all the time, or are you specifically referring to when the Lisa is reading or writing video...

So I can speak on the subject of a Radeon 7000 verses the stock Rage 128: long and short of it is you'll probably be disappointed. The two cards are actually very much in the same ballpark when it comes to raw OpenGL triangle-ing. The 7000 *is* faster, but we're talking like, I dunno, 40-50%...

Moderation note: I moved the dupe of this thread that was sitting in the "Compact Mac" section over to here and merged it with this one. The posts in the two threads seem to mostly interleave "okay", but apologies for any confusion the remaining references to "the other thread" mightt cause.

Yeah, I find that “crude” description pretty much out of left field after reading Apple’s tech documentation on it. The Model 16’s, that’s “crude”. (Literally has like two orders of magnitude less register space, the registers it did have need to be completely reloaded on every context switch.)

Thanks for the PDF links; I think I vaguely recall reading the one about UNIX on the 68000 many moons ago, but it's fun to page through again. So, yeah, again, this is a case of the slippery slope you run into trying to compare 40 year old systems and declare if they qualify as "modern". I did...

... arguments about MMUs and what the word "Preemptive" means aside, back to the OP's original question: Here's an article on Folklore.org that briefly mentions some of the basic design flaws with the original MacOS that made it difficult to bolt on "real" multitasking, among other things. The...

608x431 The weird resolution was them trying to fit as many pixels as physically possible into the Lisa's 32k of video memory. And yeah, if you do the math they nailed it, only 12 bytes unused.

I’ve never programmed for either but honestly the Lisa scheduler doesn’t sound like it’s *that* much different in practice than 16 bit Microsoft Windows. My vague and possibly flawed recollection is that Windows programs are basically designed as ”event handlers” that are supposed to regularly...

Clearly it's confusing that two copies of this same thread exist; perhaps one needs to be locked and a reference stuck pointing to the other one, or maybe I should see if there's some sensible way to merge them. Off (on?) topic, re: this: I fully agree that, yes, all these things are on a...

In all fairness, so could machines like the TRS-80 Model 16/Tandy Model 6000, which had less sophisticated MMUs. Also, FWIW, the 8088 can run Xenix (and Minix/Coherent/QNX/etc); segmentation(*), for all the bad rap it gets, actually works pretty well for creating task memory spaces with...

Citation needed here? The web seems to disagree about whether what the Lisa had counted as "preemptive" or "cooperative" multitasking. The MMU is pretty sophisticated (for the time), with multiple "task slots" and hardware memory protection, but it was also very slow. (Added quite a few wait...

Ditto Bolle’s comment. I also vaguely remember there was some super-fast upgrade that came with the weird bus downclocking limitation, but more normal G4 ZIFs run at 100mhz. The G4 upgrade in my B&W runs at 100x4, same as the original G3. (I think it’s actually just Yikes! ZIF module, it’s...

I haven’t checked if they’re still doing it or what their current price is if they are, but specialty chip vendor Unicorn Electronics was for several years at least offering a parts kit to populate those replica Apple 1 PCBs for around $600. The real killer is the shift register memory used in...

Most of the cheap and cheerful mechanical keyboards (which I'll be frank, I love the @#$# out of after finding out they exist) seem to incorporate a metal plate above the PCB to hold/stabilize the switches. I imagine you'd lose a lot of stiffness doing without it. If you want something that...