Yet another Scan Doubler

[alexh]

amigadave wrote:
I am sure there are many A500 & A1000 owners out there that would love to have a reasonable cost scan doubler.

AFAIK the chips (Denise) in the A500 and A1000 are socketed meaning you could easily make an INTERNAL version of this scandoubler using just HALF of Plaz's design.

It would be cheaper and MUCH better quality without the first of the Digital->Analog->Digital->Analog conversions.

Ditch the AL875 and add a DIL socket & plug for the denise et al.

[alexh]

WTF? Proof of concept? How lame are you? :-D

http://aminet.net/package/docs/hard/pinouts

Denise:

Pin19 = Vcc (+5v)
Pin37 = Vss (Gnd)

Pin20 = Digital RED(2)
Pin21 = Digital RED(3)
Pin22 = Digital RED(4)
Pin23 = Digital RED(5)
Pin24 = Digital Blue(2)
Pin25 = Digital Blue(3)
Pin26 = Digital Blue(4)
Pin27 = Digital Blue(5)
Pin28 = Digital Green(3)
Pin29 = Digital Green(4)
Pin30 = Digital Green(5)
Pin31 = Digital Green(6)

Pin32 = Composite Sync (A1000 = Pin39 on Agnus)
Pin36 = CCK

Just wire up these signals to the AL250 as if they were coming from the AL875 you will need to sync separate which is very easy. (During early development it would be simple to use HSYNC (38/79) and VSYNC(40/81) off the Agnus).

Tie off the missing RGB 565 input LSB's to GND

Internal scandoublers for the A500 / A1000 are nothing new.

ICD Flicker-Free video

There is a nice manual here.

Be careful with the physical size of the PCB