SuperCPU for the Vic-20

[olafL66]

If you want to support character set changes in RAM and screen memory together, you would be better off with a Graphic/Memory changes queue (like using part of the joint memory to queue up memory changes), so that you don't need to copy 4Kb repeatedly to keep the screen uptodate.

Also, you may want I/O to the SuperCPU, unless you only use it for calculations, still having the brunt of the program running under the internal 6502.

[Update] okay, now I went through ALL the thread entries, I see it's progressed quite a bit
And the VGA output from the Cartridge increases at least Graphics usability quite a lot !

[Kakemoms]

If you want to support character set changes in RAM and screen memory together, you would be better off with a Graphic/Memory changes queue (like using part of the joint memory to queue up memory changes), so that you don't need to copy 4Kb repeatedly to keep the screen uptodate.

Also, you may want I/O to the SuperCPU, unless you only use it for calculations, still having the brunt of the program running under the internal 6502.

[Update] okay, now I went through ALL the thread entries, I see it's progressed quite a bit
And the VGA output from the Cartridge increases at least Graphics usability quite a lot !

Sorry, I'm not so often here.

The VGA is generated on the fly from the internal memory changes. If you poke a byte in the internal Vic-20 memory area (including color RAM), it gets mirrored into a buffer. Thus, there is no need to repeatedly copy any 4KiB area. This buffer is the source for the VGA signal generation (including graphics). The only part that I "cheat" at is the Character ROM that is pre-stored inside the SuperVixen.

The reason for the VGA was simply to make it easier to find a monitor for the Vic-20. The number of CRT's out there is starting to dwindle, and many composite to VGA converters doesn't cope with the Vic-20 video signals. If you have a working LCD with composite signal that is fine for you, but I currently only have a large TV that has such input (and I never get to use it for my Vic-20 )

At the end of it, the VGA output will never be 100% compatible, but maybe 99%. As of now, 80-90% of the games seems to work. Some games get the graphics in the wrong places (a bug), and raster effects are not implemented yet (but I plan to do that eventually). The nice thing with this unit is that there is no modification or extra power supplies. You plug it in and it works.

As for the SuperCPU (65C02 at 25MHz), you don't need to use it, but it would speed up things considerably. The 65C02 can access the 32KiB "expansion memory area" that the Vic-20 sees (as a dual port memory), and it can access the 1MiB external SRAM on the card. All-in-all, the 65C02 will eventually be able to do most of what the 6502 of the Vic-20 can. Still, one wants to keep the 6502 running since that is the only way to have 100% compatibility with old software. I think its important with backward compatibility.

The best feature is currently the SDCard. The reason is that its fast. You can get all the Vic-20 software ever made onto one, and it takes milliseconds to load your favorite game/tool/utility. Currently SDCard SAVE does not work, but I hope to have it working by the end of this year.

At some point I need to stop the HW development and get things to production. I hoped to add a RTC, but that will probably only be as a space for the chip (nothing mounted). The first cards will be assembled manually, so my target (as of now) is to get that going in August. Final beta will therefor have to be finished by end of this month.

[eslapion]

IMHO, this project greatly suffers from overfeaturite.

We were supposed to start with a project that's supposed to offer a simple SuperCPU for the VIC-20 using a widely available FPGA development board.

Now, I try to sift through the thread and understand exactly what it does (it seems to have a VGA output now) and I can't figure exactly what the features are and how you're supposed to use them.

Bloatware!

The best feature is currently the SDCard. The reason is that its fast. You can get all the Vic-20 software ever made onto one, and it takes milliseconds to load your favorite game/tool/utility. Currently SDCard SAVE does not work, but I hope to have it working by the end of this year.

SD2IEC with JiffyDOS does a pretty amazing job already. I can't really see much benefit to load a software in 0.3 seconds instead of 3 seconds considering what the VIC-20 is to start with.

Given the choice, I would much prefer a SuperCPU for the VIC WITHOUT VGA and SD Card support next month than one WITH these features in 2 years. Ideally, make one without these features quickly and offer support for VGA and SD Card as an optional add-on later.

[eslapion]

The 65C02 is controlled by the Vic-20 and can be started or stopped by storing (POKE) to a certain register.

Which one ?

[Kakemoms]

Ok. I don’t have any way to moderate posts to this site and moderators are generally only interested in being abusive. The site has generally become a shit throwing contest site and very few interesting things about the Vic-20 appear.

You can read about the Supervixen development on mewe.com (download the app) under Vic-20. Posts appear when I have time for it. Launch of finished product will be there. I am not going to post or read anything here anymore.

Thanks for understanding.

[Schlowski]

That's too bad - anyone here interested in my preorder?

[eslapion]

[pixel]

Why don't you take a break from this site until you've finished one of your own 500 projects in the queue for once instead of pissing off everybody with unfiltered thoughts to the maximum degree? Hint: sit on your fingers, have a spliff, wait an extra day.
I'll probably have learned to build my own banked RAM cartridge before that happens.

[Mike]

[...]

Just (necro-)bumping the thread gives its topic and the original poster more courtesy than both deserve.

And ... unlike Kakemoms, eslapion actually has brought some hardware to market, no?

[eslapion]

[...]

Just (necro-)bumping the thread gives its topic and the original poster more courtesy than both deserve.

And ... unlike Kakemoms, eslapion actually has brought some hardware to market, no?

Thank you for your support in this specific matter.

Mike has noted a series of critical mistakes in this project and Kakemoms will not accept any criticism about it.

After getting specific technical information from Mike about this project, I must fully concur with him in this matter. For that reason, I consider Pixel's post as totally ill advised.

Concerning the products I have brought to market, on some of them, I made big mistakes and had to refund dozens of customers. I accepted these mistakes, learned from them and fixed the issues. That is the responsible attitude.

[MCeslapion]

Why don't you take a break from this site until you've finished one of your own 500 projects in the queue for once instead of pissing off everybody with unfiltered thoughts to the maximum degree? Hint: sit on your fingers, have a spliff, wait an extra day.
I'll probably have learned to build my own banked RAM cartridge before that happens.

And you felt like sharing this with us ... 13 months after?

Seems you should take your own advice.

[pixel]

And you felt like sharing this with us ... 13 months after?

Seems you should take your own advice.

You're lucky I didn't notice back then. Had a reason to stay away.

All cool. Am giving eslapion animal names via PM, finishing up my anger management course. We are a community. No hard feelings. Am just glad to be back.