Attack UFO PCB Recreation

[myPinballs]

Awhile ago i had an original Attack UFO pcb here that was unrepairable. During the process of trying to fix it, i redrew the entire board in a new schematic. This has led me to this project or recreating the board and adding some improvements to it. Using the knowledge and some of the same designs from the mr Do board i was able to recreate this:



- Nice small form factor as the original game was based off the 6560 ic used in vic20 computers.
- Jamma edge connector
- Test points
- Voltage LEDs
- Reset LED
- Modern reset system
- Onboard audio amp
- Reduced chip count form original
- 8 rom version options selectable by dip switch

Should be a nice board to run in a jamma cab. The only complexity is the video out system as the 6560 used composite video. Though some recent replacements have more output options. I'd like to use 15khz RGBS if possible!

 

[Georgian2]

Nice one.
Is the game color or does it use overlays on monitor?

 

[myPinballs]

Nice one.
Is the game color or does it use overlays on monitor?

Colour

 

[orac81]

That really looks smart! The original board used an NTSC 6560, any thoughts on whats needed for the PAL 6561? I think you would get a b/w picture on a PAL set unless you had a converter.
Dont forget, the original Attack Ufo code needs a few tweaks to run with a Vic20 6560, its different to the early 6560 chips.

 

[myPinballs]

That really looks smart! The original board used an NTSC 6560, any thoughts on whats needed for the PAL 6561? I think you would get a b/w picture on a PAL set unless you had a converter.
Dont forget, the original Attack Ufo code needs a few tweaks to run with a Vic20 6560, its different to the early 6560 chips.

This board i am hoping will mark the start of getting a version of the replacement 6560 ics to work with it. I am also eager to see if RGBS output can be provided or not

 

[orac81]

There are devices like this for converting svideo or composite to RGB:
https://www.ambery.com/sdv1-bnc.html
Does the board take 32k eprom and 32k sram? Going beyond the original 2k would mean you can have full mem mapped gfx in a game..

 

[myPinballs]

Yeah i know about these convertors but if the actual 6560 can be amended to be std rgbs in some version that that would be better, If not then i guess a convertor may be needed, But some of these 6560 replacements already offer dvi and vga so thats another option for arcade monitors as we have tri sync and also vga specific monitors. This is all about the arcade , regular tv stuff is not what we want ideally for this specific 6560

The board is the original design but using a reduced chip count, so for example the roms are now just a single rom not 8 2708s. And updated memory addressing for that. Ram is 2 x 6264/6116 ics instead of 4 x 2114, but not being used in full capacity, 2114 ram for the 6560 still. The idea is just to recreate the original faithfully but with less ics were possible and add improvements that make sense for arcade use like on board audio, jamma edge, power leds, test points etc etc maybe other things could be added after once its working etc

 

[myPinballs]

 

[orac81]

View attachment 52980

Brilliant!
So how much RAM is available to a program?
I wonder whether a PAL 6561 would sort of work in this "as is", even if the output frequency is all wrong. Many modern TV/Monitors will scan the input signal and "lock on" even to wrong frequencies, at least in b/w. My old Apple2c NTSC out gives a mono picture on a PAL TV via Scart.