“Vicky Twenty” - late model replacement board

[radventure]

I just noticed the Sixty Clone guy is listing the “Vicky Twenty” on Tindie. Not sure if he’s part of this forum or this has been posted already. I used the forum search and couldn’t determine if anyone else has posted this.

Great news though. Just need a VIC replacement now!

[Vic20-Ian]

Have you got a link?

[radventure]

https://www.tindie.com/products/bobsbit ... b-replica/

I would have posted it first up, but didn’t want to seem like I was pushing a product.

The Sixty Clone boards are looking popular, hopefully these are built on whatever lessons were learned from that development cycle.

[orion70]

Very interesting, I didn't even imagine that replica boards were produced also for the VIC-20.
US based I guess though...

[srowe]

Very interesting, I didn't even imagine that replica boards were produced also for the VIC-20.
US based I guess though...

Nope, UK by the looks.

[MCes]

This replica board is a great job, and probability its value is also because it's like as the original one....

Personally I would have implemented some tricks ....
1 ) the double mounting possibilities to be fitted ROMs as 2332/2364 or the 27C32/27C64
2 ) using 2x 8kram instead 2x2k+3x(1/2)k
3 ) using an xtal oscillator and not a resonant quartz that has to be tuned with special tools and a good frequency meter
4 ) using the power switch not for the power but for closing a mosfet that switch on the power (no power current on mechanical switch)
5 ) ESD protection on each line that could be connected with the external world
6 ) powering it with a 12Vcc (or with the 9Vac from original plug) with a 5V DC-DC converter inside
7 ) A better analog circuit for improving video quality
8 ) the extra tracks on CPU to be also fitted by 6502C "Sally" and W65C02S
9 ) extra "diodes" on 6522's /IRQ (and keyboard matrix) lines for permit the use of 65C02s and W65C22S

[srowe]

I'm bewildered why it has footprints for the original ROMs, they're one of the things that fail. Everything else (except the VIC itself) is easy to source.

[radventure]

I’m contemplating getting a board and the optioned components.

I’ve been looking, with no leads on a VIC repro, but I’m not completely in touch with the Vic 20 scene. Also waiting for the miracle of new breadbin cases.....

[GaryM]

What components other than the VIC 6560 is needed for the NTSC configuration? I assume the crystal. Will this PCB work?

I was also thinking getting Run-Stop Restore's Vic part kit https://retro8bitshop.com/product/parts ... ore-vic20/ but I see they only have the pal Vic.

[Lechuck]

What components other than the VIC 6560 is needed for the NTSC configuration? I assume the crystal. Will this PCB work?

Yes, you will need to replace the crystal, and, also, the Kernal ROM. Here is an example of a Vicky Twenty with that PAL->NTSC conversion, so, yes, PCB seems to work ok in both modes:

https://youtu.be/0SmYOWz4hB4

[DrVeryEvil]

Hi, I was wondering what diodes are used for the 65c22N, both for the keyboard and the interrupt pin. I get a lot of characters on the screen without touching the keyboard when I use my 65c22N. The NMI seems to lock up the computer when I try to load a program from the 1541.

Thanks everyone.
Happy New Year.

[JonBrawn]

I've built a Vicky Twenty, and it is rock solid, zero problems with random characters showing up, and I've not observed any NMI problems. I built mine as a PAL version (I'm in the US and needed a PAL system, and this seemed to be the cheapest and most enjoyable way of getting one). I'm using 65C22s, so that's probably not your problem.

I guess I'd start looking for bad or missing solder joints, pins shorted together, that sort of thing. I use magnifying glasses for this and take my time.