Thanks Nasta. I was wondering if the CPU area could be moved to a
separate sub-panel to
allow the possibility of a change of CPU type. However it seems the
connector you intend to
place directly on the CPU bus will do the job. Would it be possible to
connect a CF processor
to this connector with a bit of glue logic?
Cheers
Malcolm
ZN wrote:
> On 9/24/01 at 10:21 AM Malcolm Lear wrote:
>
>>> It's not only the peripherals that are re-used - in fact,
>>> everything but a part of the PCB slightly larger than the
>>> size of the PGA package is reused.
>>> The PCB was designed that way, it has distinct areas that
>>> can be re-designed as needed. By now it must be obvious
>>> why :-)
>>
>
>
>> Any chance of a subpanel for this area of the board to
>> allow future flexibility.
>
>
> I am not sure what you mean, Malcolm, but I guess you are talking about the
> part with the CPU.
> The GF PCB is composed of 5 areas. The PCB is the size of an Aurora, if you
> look at the top layer, so that the J1 connector is along the right edge
> (the same orientation it would be in when plugged into a regular QL), they
> go like this:
> 1) Top right: power supply
> 2) Bottom right: Flash ROM and bus termination
> 3) Top mid: CPU area
> 4) Bottom mid: SDRAM and logic chip (this is also a sort of 'hub' where
> everything connects)
> 5) Left: IO area.
>
> This refers to the areas on the PCB - they cannot be separated mechanicaly,
> a major upgrade would require a PCB redesign, but the 'sectored' approach
> limits the amount of area that needs to be changed.
> Between the CPU and the SDRAM/Logic area, there will be a connector, which
> interfaces directly to the CPU bus, and alowes a second CPU or an upgrade
> CPU, or even a peripheral that needs very high bandwidth, to be connected
> to it - however, only ONE of these at the same time due to signal loading
> and integrity. Although the 'vertical stacking' connection isn't very nice
> mechanically - not a simple as a 'slot', but it ensures good signal
> integrity because the signals are routed to very short lines.
>
> I hope this answers some questions,
>
> Nasta
>
>
>
