Macintosh Portable Accelerator: feasibility study

[Trash80toHP_Mini]

Getting way ahead of myself here, but came up with a pressing question and a request for help.

According to the Portable Devnote the Luggable (Backlits need not apply anytime soon) uses a modified SE ROM and under cursory examination, the changes don't appear to affect what's necessary. Memory mapping is another story, but that serious hurdle can be addressed if and when.

Question: can Compact Virtual, coded for 68030 accelerators to address additional RAM under VM for 68000 equipped Plus SE, etc, be installed on the Portable and load successfully under one System or another without the system suffering a gruesome death?

Help needed here, my Luggable needs work before I can try to get anything running, much less tested. If we can't verify CV compatibility, there's no point in attempting anything fancier than converting the Performer to run at 33MHZ in a Luggable compliant configuration.

Portable seems halfway between the SE and PowerBook 100, accelerators for both are currently on the impossible dream list.

Then again, if someone here is willing and capable of disassembling and tweaking Compact Virtual for use in Portable and PowerBook 100, we've have a real game changer on our hands.  []

 

[techknight]

Believe it or not, the Portable's core logic is a bit closer to an LC than it is a SE. its kinda sitting in the middle there. the GLU was engineered with an 030 in mind, but for some reason they shoehorned a 68000 in there instead probably for power consumption reasons. This conclusion was drawn from studying the schematics redeeming the fact that the GLU contains most, but not all of the logic for the synchronous bus which would have been a requirement for that setup in an 020 machine. 

 

[Trash80toHP_Mini]

Curiouser and curiouser! Can't wait for someone to report on "Compact Virtual." I also need to read up on "Virtual," which was for the Macintosh II et. al. in the 8MB 24bit dark ages. Thanks for that info, now we've got another code base to peruse if the Luggable's discrete component implementation of the PowerBook 100 Misc. GLU give up bopkes.

Haven't studied the PDS yet, same SE signals, different pinouts? Pulling something like that'd be just like the infinite loopiness.

 

[Trash80toHP_Mini]

My gut tells me that the performer will run in the SE just fine sans 68000 when I test that config and that the Luggable will do the same.

Just gotta get it on the PDS for either an incredible achievement or epic fail! Either works for me! []

 

[LaPorta]

This is almost four years old, but I was wondering if this got anywhere, Trash. Just been thinking of how I could add some pep and juice to my Portable...

 

[Johnnya101]

According to a very quick read of the Apple technical notes on the portable, the slot is the same electrically, but who knows if that is actually the case.

A PDS accelerator Ethernet card combo for a portable would be killer (if at all possible).

I notice they have a rom expansion slot as well, that I don't think anyone really did anything with. A rominator II expansion card would be pretty cool. That plus accelerator plus Mac effects ram card would make a nice portable.

 

[LaPorta]

I've got my RAM card; I heard that the RAM slot was used to power the backlit upgrade for the non-backlit model. I looked a bit at the "Designing Cards and Drivers" book, and saw the slots aren't pin-compatible with the SE, and the power pins are limited to the amount of current they supply...but otherwise it could be possible. There isn't much room in that case, but maybe if you made a two-part card with a cable you could put the other part of the card into the ROM or Modem slot with a blank connector just to hold it in place. Wouldn't it be killer to have a functionally equivalent accelerator for the Portable like those in the SE?

 

[Byrd]

The Portable is the sort of vintage Mac that almost needs to stay slow based on its archaic appearance!

 

[Trash80toHP_Mini]

PFFFT! It's hotten' . . . Other than Sony's masterwork, the frumpy 100 series pales in comparison to the Portable.

This is almost four years old, but I was wondering if this got anywhere

It has and hasn't. Sent my Performer Accelerator and some other goodies off to Bolle before the holidays. He's to play with it, finishing the schematic I got started somewhere else and reading the GALs. Target was the Portable at first, but back burnered that one. The notion of a 32MHz 030/FPU Processor Card replacement for the PowerBook 100 would be the actively tilted windmill at present.

 

[LaPorta]

Well, if you pull it off on the 100....please adapt it for the Portable! I'll buy it in an instant.

 

[Trash80toHP_Mini]

There isn't much room in that case, but maybe if you made a two-part card with a cable you could put the other part of the card into the ROM or Modem slot with a blank connector just to hold it in place. Wouldn't it be killer to have a functionally equivalent accelerator for the Portable like those in the SE?

Damn betcha! There's plenty of room in the case for the Performer, I've got AI design studies somewhere around here . . . if they're still there? Performer Plus or equivalent with SIMMs and Compact Virtual is another story in terms of Power and Cubic. But you can pretty much throw Apples power limit specifications for the Portable out the window these days. Nobody interested in an accelerator will be spinning rust under the bonnet. There's still a limit there, but a very nice bit of the overall power and cooling budget becomes available with SD on the SCSI bus.

 

[Trash80toHP_Mini]

Well, if you pull it off on the 100....please adapt it for the Portable! I'll buy it in an instant.

That's a long way off, besides, I never sell anything. But it'll be an open source development team project when it kicks off . . . if and when. I just line up the notions, building blocks and toys, for tempting folks who are competent at pulling off this kinda crap.

 

[LaPorta]

Ok, well, count me in to download the instructions!

 

[Trash80toHP_Mini]

They'll be forthcoming, hopefully long before another four years elapse. When @Bolle has a chance to work on my Performer, I can try to pull off thruhole prototype boards for a supported machine. If and when, I can begin to play with two sacrificial boards in question. Dug up the teaser for Micromac's Performer in Portable/PowerBook 100. I see you were interested even then.

MicroMac Performer Redux: Cloning a 68030 Accelerator for Compact Macs

This one is mine, it came as wonderful surprise in my Drexel 128K that had been upgraded to Plus and then to "4MB SE/30" status over the course its remarkably extended useful lifetime. Not one of the original, silk screened student versions we've come to appreciate, but a killer machine from the...

68kmla.org

One of the reasons for doing PB100 first would be the power connector on the board. Now that the Portable schematic was leaked onto the web, it may be possible to track down the Power Manager implications for active/low power/sleep in running Performer on the Portable PDS from the PB100's processor board clues.

PB100 appears to be simple by comparison as it looks to me to be compartmentalized? I think Sony probably had enough room on the logic board to keep its itty bitty Portable a closed system. Hope would be that Sony intentionally snuck the very first processor card/slot implementation past Apple's gatekeepers for just such an upgrade mechanism.