NEC uPD7220/GDC Design Manual
ard at p850ug1.demon.co.uk
Thu Jun 18 14:34:10 CDT 2009
> Andrew Lynch wrote:
> > What I really need to know is if I can implement a simple circuit using few
> > enough 74LS TTL ICs to fit on a Eurocard ECB board. That means it can't be
> > more than about 30 maximum. Using high capacity SRAMs should help but I
> > think it requires some funky latching mechanisms to share the video address
> > and data lines.
> Did you get the one copy at this link ?
> It doesn't have schematics per say, but there's plenty of info in that pdf.
I thought hte Epson QX10 used a 7220, and I've just checked the technical
manual and it does.. The video circuitry is on a daughterboard, the
newer one used an ASIC so the schemaitcs aren't a lot of use to you, but
the older one was the 7220 + DRAM + TTL + a chracter generator EPROM. It
doens't look _that_ complicated...
I think the QX10 technical manual is on a web site somewhere, and
includes said schematics.
May be of interest...
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