Macintosh Portable Slot Hackage

[Bunsen]

the SE/30 chassis, which adds four NuBus slots to the Mac SE/30.

Say what?? 8-o

 

[Trash80toHP_Mini]

I still need an answer about the FDDs if anyone knows offhand, but in the meantime I'll ask for critique of this reboot of the proposed hack:

In order to get around the limitations and quirks of the Luggable's PDS, I'm looking at wedging the Micromac card directly onto the 68000 in a manner similar to the "soldered on socket" workaround for Killy Klip resistant DIP 68000s in the Compacts. Using a PB FDD that draws less water than the Portable's, It looks like I can machine away enough clearance to attach the Accelerator directly to pins soldered to the SMT 68000 using a simple adapter PCB soldered to the underside of the unpopulated EuroDin connector thru holes. The 68000 socket almost rests on the Luggable's MoBo, with the only three components "in the way" nestled neatly withing the socket!

On the driver side, if the standard SE-PL-CL driver doesn't work, I'm wondering if I can just lift the power leg of the SMT 68000 so the driver shutting it down never need come into play? The Accelerator would "just work" in place of the 68000 in that config.

Dunno, thoughts? :?:

 

[markyb86]

This is information on the external floppy port for the compacts/portable.

I wonder if it would help answer the question if the Powerbook FDD is electrially compatible.

http://support.apple.com/kb/TA48050?viewlocale=en_US

http://www.hardwarebook.info/Apple_Macintosh_Internal_Floppy_disk_drive

 

[Trash80toHP_Mini]

THX, unfortunately, that pinout remained unchanged, or so it would seem, but electrically that may not be the case, IIRC.

Interesting twist:

Not sure about it, the clock on board says 25.175MHZ(z?) so I'm wondering if this may be a multiplier of one of the 68000 signals that translates into the 2X clock rate increase for the 16MHz 68030?

The only other ICs on MicroMac board are the five:

GAL16V8B-15LJ - High Performance E2CMOS PLD Generic Array Logic

• HIGH PERFORMANCE E2CMOS® TECHNOLOGY

— 5 ns Maximum Propagation Delay

— Fmax = 166 MHz

— 4 ns Maximum from Clock Input to Data Output

— UltraMOS® Advanced CMOS Technology

If the above means these can be driven up to 166MHz could I then replace the 68030 with a 33Mhz part for 2x acceleration over the 16MHz 68000?

Is the 6688802 detected and automagicly enabled by its appearance on the CPU bus or is there driver support necessary?

WTHeck would be the function of an IC implemented on the empty pads on the MicroMac accelerator?

 

[Trash80toHP_Mini]

One more question: :?:

Since the accelerator runs off whatever ROM is resident on the host MoBo, why should the memory mapping of the host system be any sort of problem?

 

[Trash80toHP_Mini]

Back to the PDS hacking roots of this bit of silliness:

Given: the Portable's memory slot has exactly 1/2 the signals necessary to address its full memory map allocation.

Given: the full set of address signals are available on the PDS

Postulate: RAM appears to be buffered, but no Memory Controller is present, as on the SE

WAG: The other four MB of RAM could be added to a PDS card

If that's not possible, might a dual card setup be possible to Max out the memory map allocation by jumpering signals from PDS to Memory slot?

What are the chances for Compact Virtual to be run on the Portable for additional RAM to be addressed as a silicon disk via VM?