> From: wasteking1
>
> i wish to finally do the memory chip upgrade --i have got the
> 6264LP-12 chips from Jameco Electronics . but in reading the
> instructions im not sure what the 'reverse jumper ' procedure is
> . it appears you MUST switch sometning in the wiring between
> chips Z8 and Z9 but the description of the pins is confusing.
> does anyone have a specific diagram or photo of this ? before and after?

There are two 3-pin jumper platforms between those chips; you need to switch
the vertical one. Just move the jumper over by one pin so that it connects
the center pin to the rear pin. (I'm basing this on looking at the PC
layout--I'm not about to drag my Polaris out and open it up.)

The horizontal jumper was put in to support 16Kbyte RAMs, but I'm not sure
that Hitachi or anyone ever actually made any in a 28-pin DIP.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...