Re: vortex memory upgrade?

[mark <mark@grape.no>]

Do you have your Vortex schematic posted anywhere Kim, I might wanna take a
peek myself, but without a map I...er...?
might not !!

MArk Red

Kim Flint wrote:

> At 12:39 AM -0800 11/17/99, b.knox wrote:
>
> >"Audio memory consists of 64K x 4 DRAMs, which provide a total of 2
> >seconds of
> >delay. The unit may optionally be configured with 256K x 4 DRAMs, with
> >the
> >addition of U10."
> >
> >an 8 second vortex? eeep um that would be er, nice.
> >
> >no other mention is made of this "memory upgrade" except in the actual
> >schematics...
> >the U10's look like they make up an extra bit of the DRAM controller ..
> >part number 74HC125 (what are the little triangles again? capacitors?)
> >...  it
> >looks as though the routing to the DRAM chips must be completely changed
> >to get
> >the 256K's in there... i'm not too sure... U10 is included in the
> >schematics as "spare".. don't know if they're actually inside the box
> >... getting ye olde 256K DRAM should prove entertaining enough anyway...
> >
> >i've emailed both lexicon and Bob Sellon (of jamman upgrade fame) about
> >this but with no response ... anyone heard of such an upgrade?
> >
> >i'd really like to know if 8 sec / dual 4 sec vortex bliss is possible
> >in this universe ...
>
> 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.
>
> Whether software will recognize the additional memory is a whole other
> matter. Looks like fun though, someone should try it and let us know how 
>it
> comes out.
>
> kim
>
> ______________________________________________________________________
> Kim Flint                   | Looper's Delight
> kflint@annihilist.com       | http://www.annihilist.com/loop/loop.html
> http://www.annihilist.com/  |

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