Re: vortex memory upgrade?

["b.knox" <b.knox@latrobe.edu.au>]

Kim Flint wrote:
> 
> I looked at my vortex schematic. If you want to try this, looks like you
> need to pull out the existing dram chips, U15, U18, U20, U21. Add in 
>256kx4
> drams chips at U16, U17, U19, U22. (They have part# 44256 on the 
>schematic,
> that may correspond to an actual part. You can probably find them surplus
> somewhere.) The you add in tristateable buffer chip 74HC125 at U10, which
> brings out an additional address line to the dram.
> 

thanks Kim !! they wouldn't be the same drams that max out jammans would
they?  

> Whether software will recognize the additional memory is a whole other
> matter. 

this is what has me worried ... it really looks like the hardware
upgrade itself is unfinished, very slim chance of the software
recognising it ... on the other hand the software seems robust enough in
other respects ... maybe it's crazy enough to work ... whether the mod
is reversible is yet another whole other matter.

> Looks like fun though, someone should try it and let us know how it
> comes out.
> 
> kim
> 

yep... wish i had a spare to try it on .. is -fun- the right word ?? :)
i don't think i have enough confidence with a soldering iron to launch
into this obviously non-trivial mod... if anyone wants to hack around,
e-mail me and i suppose i could scan the schematics while the "mission
impossible" theme plays in the background .... shhh no one tell lexicon
though ... (as if they'd care) ... i think i'll at least open the box up
and see if "don't do what you're thinking of doing" is written on the
circuit board ... maybe that wouldn't stop me even, har ... if this mod
works it could really push the 'texter from the sublime to the
ridiculous.

brad