OS 9 with 2GB of Ram.

[Daniel]

The 'vm  ' 42 makes use of FE0D and FE0B in one function, and I have no clue what those ones do

It also uses FE05 in another function, which is _MoveToECR. It writes to emulator control registers 6, 7, 8, and 14, in that order.

[ELN]

Neither FE0D nor FE0B result in a PowerPC trap, at least when run from the first few bytes of ROM. Maybe they also set Emulator state?

What do they seem to be taking arguments?

[Daniel]

They take a page number in A0, and 0xFFF in D0. The same page# is put in both. This function's pointer is placed at offset 0x24 of VMVectors (global variable at address 0xCF0), but only if the cpu is better than a 601 (the 601 version of this routine is just a RTS). I have no what calls this function or what its argument is.

[ELN]

Possibly some simple function that the Emulator accelerates using clever post-601 PPC instructions? Zero a page using DCBZs?

[Daniel]

Not sure.

I have mostly finished looking through the 'vm  ' 42 resource. It looks like it is essentially a wrapper for NK VMCalls. It puts a lot of function pointers in VMVectors, and it initializes its globals, but I am not sure it does a lot of stuff itself. I don't even think that it takes over the bus error trap. It definitely doesn't read and write pages to disk. Somewhere in the vast assortment of Mac OS 9 code there is something which actually uses this API to provide VM services. My best guess for its location would be the Process Manager, Mixed Mode Manager, or the Memory control panel.

MPLibrary has a lot of functions related to the Area VM system. It might do MPTask VM itself, or it might offload it to something else. The 'ager' MPTask might be interesting to look at, because it apparently does page aging stuff.

[MacTron]

We can put the virtual Memory on a SSD controller on a 64bit PCI card. That would give us a throughtput of 266Mb/s with some CPU overhead. It wouldn't be that hard to design a 64bit PCI SSD controller.

I have done this before: connecting two SSD's to a Seritek 1eVE2+2, ( a full length 64 bits SATA PCI card) in RAID mode. The maximum throughput was 190 Mb/s IIRC, I'll will seach for the post where I wrote the data.

[IIO]

isnt that what you would get with only one SSD, too?

[Daniel]

By setting breakpoints in MPLibrary APIs, I believe that the 'ager' task is inside MPLibrary itself. This means that MPLibrary contains code which actively manipulates Area VM stuff.

[Daniel]

I just realized I completely missed the 'ptch' 420 resource. 
It sets up the 'vm  ' 42 resource and uses its vectors a lot.

I guess I should start reversing that...

[ELN]

#blazeit

[darthnVader]

[ELN]

Please explain.

[Protools5LEGuy]

I think it should be explained by someone who understands.
https://forums.macrumors.com/threads/whats-wrong-with-this-picture.2120551/#post-26111977

[Protools5LEGuy]

I am sorry Darthnvader, bit I couldnt let Elliot with the question.

[darthnVader]

Please explain.

Yes, it's Qemu-system-ppc, seems they did a little trickery with Book-E and some older commits from a few months ago can boot OS X with very near 4GB of Ram. For OS 9 the Mac OS ROM fails to load, but I'm sure that could be addressed if we can get around the 1.5GB limit for the OS itself.

[macStuff]

i never put more than 1gb of ram into an os9 machine
no need for anymore ram than 1gb
the os simply does not use it effectively in my opinion

so theres absolutely no point in trying to get more
MY opinion

[darthnVader]

i never put more than 1gb of ram into an os9 machine
no need for anymore ram than 1gb
the os simply does not use it effectively in my opinion

so theres absolutely no point in trying to get more
MY opinion

We do it because it's there, and, hello pirate:-)

[ancient]

Even given OS 9's partition limit of 128Gb, that's a lot of virtual memory.

hm, i use some 30+ partitions with OS9 which are bigger than that.

The 128Gb limit (actually 190Gb) is only for the startup partition.

Very useful to know , the limitations are not that bad then so with a seritek Sata card I can have 2tb secondary non booting drive single partition? does formatting larger drives in OS9 become an issue software wise to format them?

[IIO]

Very useful to know , the limitations are not that bad then so with a seritek Sata card I can have 2tb secondary non booting drive single partition? does formatting larger drives in OS9 become an issue software wise to format them?

you can with some controllers, but it is better to make 4x500 IMO.

i use x500 partitions inside (PCI) and 1.5 tera single partitions via firewire - and only for data which do not need to be maintained by norton disk destroyer or data recovery programs (or at least not under OS9 and 10.4 PPC).

[darthnVader]

Got around to running memtest on Qemu, segmentation fault if you exceed 2 GB.