How to make the Phase 5 CV64/3D ScanDoubler work in the A2000 / A3000 video slot
Stéphane Guillard -firstname.lastname@example.org
1 - Introduction
Phase 5 (German manufacturer of superior quality Amiga hardware extensions) was making, a few years ago, a graphics board called the CyberVision 64/3D (based on the S3/Virge chipset).
This board came without a scandoubler (a system which would enable viewing 15 KHz original screenmodes on the >31 KHz monitor connected to the CV64/3D).
Such a system was proposed as an option : the CV64/3D Scandoubler. Here it is, sitting in the A2000 video slot :
The board was able to run in Zorro II (Amiga 2000, 3000, 3000T bus technology) and Zorro III (Amiga 4000, 4000T).
But the scandoubler module was only made to fit the specifically enhanced video slot of the A4000/4000T, and would not even mechanically fit in the A2000/3000 video slot.
I used to run an A2000 with a Picasso IV board, which has an universal scandoubler / flicker fixer. One day, I bought an A4000 equipped with a CV64/3D with its Scandoubler, and decided to install the CV in the 2000, and the Picasso IV in the 4000.
I found that problem, which I tried (successfully) to fix.
2 - Solution
1 - mechanically, the Phase 5 scandoubler won't insert into the A2000 video slot, because the board edge connector is too long. It was enlarged between A2000/3000 and A4000's to add more color bits and a higher frequency dot clock. Just use a saw to carefully make a notch in the board edge connector, to make room for the plastic edge of the Amiga slot. If you do it like I did, you will still be able to use the scandoubler in an A4000, since the notch is to be made between 2 connections, which you must just rip off a bit. Cost : $0. Here it is (above the right chip) :
2 - the provided 10 way jumper cable, to be run between the CV64 and the scandoubler, is to be replaced by a longer one, to link the CV64 which you put in a Zorro II slot, and the scandoubler which you put in the A2000 video slot. Buy 25 cm of 10 way flat cable, and 2 HE 10 pin cable connectors. Cost : $4. Here it is, running from the scandoubler (on the right), under the power supply bed and the TekMagic 060 (which sits in the processor slot), to the CV64/3D (on the left) :
3 - you do 1 & 2, and it does not work. Then you take A2000 doc & A4000 doc, and you see that on pin 5 of CN203 (the connector which is part of the A2000 video slot, the closest to the back of the case), pin 5 in A2000 is not connected, and in A4000 brings 28 MHz clock to the video slot. Just solder a lead between pin 5 of the video slot CN203 and either pin 6 of the A2000 CPU slot, or one end of the micro fuse which is just aside the 28 MHz main oscillator on the A2000 motherboard. Voilà ! Here you can see the scandoubler end of the wire, soldered onto the third connector pad from the left :
Enjoy, the Phase 5 scandoubler is not the Picasso4 Flickerfixer, but it is still great for using old Amiga software on a CV64/3D equipped Amiga2000, without requiring a second monitor. Furthermore, due to the internal link between CV64 and its scandoubler, you simply plug your main monitor at the scandoubler DBHD15, and it automatically switches between scandoubled signal and GFXboard one !
3 - Thanks to