Thanks, so this appears to be some kind of official thing.
But what are the applications for this? Are there any?
Search found 43 matches
- Sun May 19, 2024 11:40 am
- Forum: Hardware and Tech
- Topic: Audio to expansion port
- Replies: 4
- Views: 89
- Sun May 19, 2024 9:12 am
- Forum: Hardware and Tech
- Topic: Audio to expansion port
- Replies: 4
- Views: 89
Re: Audio to expansion port
Hi. I have a VIC 20 CR board with a bodge wire on the back that appears to connect the audio pin of the VIC chip to pin Y on the expansion port via a 1K resistor. What does this actually do? Are there any cartidges that use this? Do you have a picture? Somewhere I've seen a schematic this this labe...
- Sun May 19, 2024 8:57 am
- Forum: Hardware and Tech
- Topic: Audio to expansion port
- Replies: 4
- Views: 89
Audio to expansion port
Hi. I have a VIC 20 CR board with a bodge wire on the back that appears to connect the audio pin of the VIC chip to pin Y on the expansion port via a 1K resistor. What does this actually do? Are there any cartidges that use this? Apologies if this has been answered already, I did a quick search on h...
- Fri Mar 08, 2024 2:09 pm
- Forum: Hardware and Tech
- Topic: 6561 Die Shot Reversing Explorations
- Replies: 289
- Views: 130936
Re: 6561 Die Shot Reversing Explorations
[...] The only bit that doesn't make sense is that X=35 input. I've simulated this and VCNT.RESET goes high when X=35 on the LAST LINE. It doesn't make sense and clearly I have to check things over a few more times and try to work out why it doesn't reset at that point on the last line. I'm going t...
- Wed Dec 27, 2023 5:30 am
- Forum: Hardware and Tech
- Topic: S-Video conversion possible as plug-and-play solution?
- Replies: 87
- Views: 85558
Re: S-Video conversion possible as plug-and-play solution?
Bit late to the party. It appears the S-Video mod being talked about here takes the chroma directly off the chip, albeit with a resistor + cap in between. This does not feel right to me. Should there not be a proper buffer/amplifier in between? I.e. similar to how the C64 modulator operates.
- Sat Nov 04, 2023 11:03 am
- Forum: Games
- Topic: In the making: Arukanoido – an Arkanoid clone
- Replies: 610
- Views: 166587
Re: In the making: Arukanoido – an Arkanoid clone
I did an audio capture of the high score music. Here are 3 waveforms from the same sample from different VIC20s (VIC20 CR model, NTSC 'old' (2-prong power), PAL old.) vicsamples.png The NTSC old model is the clear winner here with 4 distinguishable levels corresponding to 3 voices. The other models ...
- Thu Oct 26, 2023 10:48 am
- Forum: Emulation and Cross Development
- Topic: Colour blue on NTSC VICs.
- Replies: 17
- Views: 5790
Re: Colour blue on NTSC VICs.
If needed I can do a new capture - in theory I could also measure the phase offset between light and dark colors with my oscilloscope, although how exactly I haven't yet found out.
- Wed Oct 25, 2023 11:59 am
- Forum: Emulation and Cross Development
- Topic: Colour blue on NTSC VICs.
- Replies: 17
- Views: 5790
Re: Colour blue on NTSC VICs.
The order from left to right is black / white red / light red cyan / light cyan purple / light purple green / light green blue / light blue yellow / light yellow orange / light orange so then green would be at index 8 indeed. I also notice that yellow is also very greenish (compared to light yellow....
- Wed Oct 25, 2023 11:08 am
- Forum: Emulation and Cross Development
- Topic: Colour blue on NTSC VICs.
- Replies: 17
- Views: 5790
Re: Colour blue on NTSC VICs.
The NTSC VIC has two variations of cyan apparently. I found this post that may be related https://www.lemon64.com/forum/viewtopic.php?p=979712 My NTSC VIC cyan looks distinctly blue so I guess this is an older variant - see images from capture card (NTSC contrast is a bit off but the color should be...
- Mon Sep 04, 2023 10:50 am
- Forum: Hardware and Tech
- Topic: Colour palette entries
- Replies: 4
- Views: 3293
Re: Colour palette entries
Apparently early versions of the 6560 had a different palette where cyan would look more like a light blue rather than the colors described here. (I think I may have one of these.) Could be interesting to create a variant for that too.
- Mon May 08, 2023 9:32 am
- Forum: Hardware and Tech
- Topic: FPGA 6561 - PAL Questions
- Replies: 25
- Views: 4778
Re: FPGA 6561 - PAL Questions
PAL VIC-20 is 312 lines
- Wed Apr 12, 2023 9:14 am
- Forum: Hardware and Tech
- Topic: FPGA 6561 - PAL Questions
- Replies: 25
- Views: 4778
Re: FPGA 6561 - PAL Questions
Re cyan being off: I seem to recall that older 6560 variations generate a different cyan that is more blue-looking. E.g. this is what my NTSC VIC20 looks like bt848_ntsc_comp_vic20-ntsc.png My PAL VIC20 looks like this bt848_pal_comp_vic20.png apparently the cyan on later 6560 models should look mor...
- Mon Apr 10, 2023 9:10 am
- Forum: Hardware and Tech
- Topic: FPGA 6561 - PAL Questions
- Replies: 25
- Views: 4778
Re: FPGA 6561 - PAL Questions
There is some research data here (partly German) The PAL colour generation is a bit problematic because the even and odd lines have different angles/amplitudes for each of the colours. This is probably due to the way the colours are generated on the chip. In theory all dark colours (2-8) should have...
- Thu Mar 16, 2023 7:54 am
- Forum: Hardware and Tech
- Topic: Video noise on VIC-20
- Replies: 51
- Views: 13269
Re: Video noise on VIC-20
I would have thought those Meanwell thingies would work fine, but apparently not then. One thing you could do is get a separate 5VDC supply from somewhere and then combine that with the 9VAC from an old VIC-20/C64 PSU. There are Y-cables that let you combine these. Or at least there used to be, I ha...
- Wed Mar 15, 2023 6:13 am
- Forum: Hardware and Tech
- Topic: 6560 FPGA Progress.
- Replies: 152
- Views: 14966
Re: 6560 FPGA Progress.
Very good video. The VIC (6560/6561) in fact has sepearate luma resistors for each colour, see for example this thread (partly in German) https://www.forum64.de/index.php?thread/110862-helligkeiten-der-c64-pal-palette-zum-100-mal/&postID=1699320#post1699320 I think it also may have been discusse...