The specific parts used by Ensoniq were NEC uPD431000 with, IIRC, 70ns access time; these are no longer made, but they are fundamentally 128kx8bit SRAM circuits in a 32-pin DIP (or PDIP) package. You need a pair of them.
I think something like this should do it:
Same package, 55ns access time so should be more than fast enough.
Best wishes,
// Christian
On 13 August 2014 12:59, sonofspy777@yahoo.com [Ensoniq-VFX-SD] <Ensoniq-VFX-SD@yahoogroups.com> wrote:
Hi,I checked my VFX-SD and it only has the original 25,000 sequencer notes availableDoes anyone know what ICs are used for the sequencer memory upgrade?If they are available from electronic parts suppliers it seems silly to pay $40-$50for two of them...TIA-Alan