Questions about 1702

[Jeff-20]

I do not own a 1702 (yet), and I couldn't find the info in our wiki.
1. What are each of the knobs under the front panel for?
2. I am assuming from the mono input that the 64 was also mono, right?
3. Is there any way to adjust for overscan?
4. Can the VIC also output luma, chroma?
5. Where's the speaker?

The monitor would be perfect if there were internal options for RF input or even s-video!

[IsaacKuo]

I do not own a 1702 (yet), and I couldn't find the info in our wiki.

I do not know if all 1702's had the same knobs. I can only speak for mine (I own two of them, identical).

1. What are each of the knobs under the front panel for?

Tint, Color, Bright, Contrast; H Position, V Hold, Volume

In addition, there is a toggle switch in the back to switch between the front and rear video inputs. Both the front and rear audio inputs are always both wired to the speaker, so they are de facto mixed to the speaker.

The front video input is composite; the rear video input is essentially S-Video (although it uses two RCA plugs instead of the S-Video connector).

2. I am assuming from the mono input that the 64 was also mono, right?

You mean the Commodore 64? The Commodore 64 had mono audio output.

3. Is there any way to adjust for overscan?

Not with the externally available knobs. There may be internal pots for such adjustments; I don't know.

4. Can the VIC also output luma, chroma?

Not in the stock configuration. There's an S-Video mod for PAL VICs; I don't think it works for NTSC VICs. I wouldn't recommend it even if it were possible. The NTSC VIC20 looks awesome with the composite output already, due to the way it works, and you'll need to keep the VIC20 in its stock configuration if you want to take advantage of my high resolution sub-pixel rendering techniques.

5. Where's the speaker?

The top, near the right side.

The monitor would be perfect if there were internal options for RF input or even s-video!

The 1702 monitor accepts S-video signals in the rear input. The Luma and Chroma inputs are S-video. If you can find a cheap S-video cable that has a figure 8 cross section instead of a circular cross section, then you can simply chop off one end and crimp on a couple RCA connectors to make your own S-video to 1702 converter cable. This sort of cheap S-video cable often came with old SVHS VCRs.

[gklinger]

There's an S-Video mod for PAL VICs; I don't think it works for NTSC VICs.

It does.

I wouldn't recommend it even if it were possible. The NTSC VIC20 looks awesome with the composite output already [...]

It looks better with separated luma and chroma output.

[...] due to the way it works, and you'll need to keep the VIC20 in its stock configuration if you want to take advantage of my high resolution sub-pixel rendering techniques.

Versus the advantage of enjoying a dramatically better image with all the software released over the last 28 odd years that doesn't use your technique. Not a difficult choice.

[IsaacKuo]

Dramatically better? A matter of opinion, and it depends on the specifics of your video hardware. I know it wouldn't make a dramatic difference on a 1702--even with the C64's higher resolution there's at best a minor visible difference between using the composite input and the S-video input. The specifics of the NTSC C64 and VIC20 output signals are similar enough that I can tell what effect an S-Video mod would have on the VIC20 output.

It depends on exactly what sort of TV you're using, and the details of its comb filter. On my various TV sets and projectors, an S-Video mod for the VIC20 would not be worth it. Not for a single one of them.

For example, my Mitsubishi HDTV has a 3D comb filter. The composite and S-video outputs for C64/VIC20 are essentially indistinguishable, except for the VIC20 in interlace mode (where there are some periodic glitches). The VIC20's blocky pixels have razor sharp borders regardless of color combination.

The 1702 has a crude notch filter, but due to its relatively poor resolution and the unfortunate levels of crosstalk in the Chroma/Luma S-video inputs the composite and S-video inputs look virtually the same (for the NTSC VIC20/C64 style of 180 degree phase alternating fields). With a 1702, you never get razor sharp edges regardless of input.

[rhurst]

Jeff, my VIC 20s paired with a 1702 look fabulous -- I rarely bother hooking it up to a TV anymore. The 1702 speaker is okay for VIC audio.

IMHO, I am certain an S-Video mod to VIC can be helpful when paired with a proper video device (not 1702), but it's like hooking up VIC's audio to a stereo -- why bother unless it makes nice for a permanent setup for cabling? For VIC-II, yes, S-Video and stereo makes for remarkable differences -- at least for my TVs.

[gklinger]

Dramatically better? A matter of opinion [...]

On the one hand we have the opinion of someone who has never seen an NTSC VIC-20 with the S-video mod and was not until a few hours ago aware that such a thing was possible so their opinion would be better described as a belief and on the other hand we have the opinion of someone who has a VIC-20 with the S-video mod and is basing their opinion on their observations.

[IsaacKuo]

I have an intimate knowledge of how it works on the C64, along with first hand experience on the display hardware in question, and the theoretical knowledge to comprehend why the signal from the C64 is essentially the same (if you're using plain 160x200 low resolution mode rather than 320x200 hires mode).

I was under the impression that the S-Video mod didn't work on NTSC VIC20's because of a thread where someone tried to do it on an NTSC VIC20 and it didn't work. I understand the theory just fine.

Of course, I'm of the opinion that I would rather not cripple the capabilities of my VIC20 hardware just because someone else is of the incorrect opinion that it would make a "dramatic" improvement. (Certainly not with my 1702 monitors, and absolutely not in the case of my currently connected Apple Monitor III.)

[gklinger]

Well, that's me told. How could my empirical evidence ever hope to counter your theories and impressions.

[dragos]

The difference is night and day. It does not "cripple" the hardware in any way, just makes it better.

Where, praytell, can we see this "sub-pixel rendering technique" ? or is that theoretical knowledge as well....

[IsaacKuo]

Since I don't yet have any functional hardware for transfering files between PC/CBM, my subpixel rendering program demos are only on my VIC20/1541 disks. They work best when connected to a high resolution monochrome monitor, which is why my VIC20 is currently connected to one. The 1702's much poorer resolution makes it less suitable.

I hope to get something working to transfer files at some point soon, so I can use cross compiled DASM programs. My dynamic allocation drawing routines are well suited for this, because 4K of "video" RAM simply isn't enough for a full screen fixed bitmap pair.

[Alan]

I have an intimate knowledge of how it works on the C64, along with first hand experience on the display hardware in question, and the theoretical knowledge to comprehend why the signal from the C64 is essentially the same (if you're using plain 160x200 low resolution mode rather than 320x200 hires mode).

If you think composite video on a C64/1702 setup is "essentially the same" as seperated luma/chroma video, then your knowledge is nowhere near as intimate as you think it is.

Seperated video looks far, far better. The difference is, dare I say, Dramatic.

[IsaacKuo]

That isn't what I wrote. Read it again, carefully.

[Alan]

That isn't what I wrote. Read it again, carefully.

The intent was, and is, obvious.

I know it wouldn't make a dramatic difference on a 1702--even with the C64's higher resolution there's at best a minor visible difference between using the composite input and the S-video input. The specifics of the NTSC C64 and VIC20 output signals are similar enough that I can tell what effect an S-Video mod would have on the VIC20 output.

Now that several people have pointed out that you don't know what you're talking about you want to imply that you meant something different. Good luck.

Again, luma/chroma seperated video on the C64 is strikingly better than composite. From all accounts this is also true for the VIC, despite what you (who has never seen it) might want to believe.

[IsaacKuo]

Again, luma/chroma seperated video on the C64 is strikingly better than composite.

As I have already explained, this depends on the specific hardware involved and it is a matter of opinion. With my Commodore 128s and 1702s, I have both types of cable and I would never miss the separated cables. Yes, there's a noticeable difference and I never denied that. But it's a minor difference, in actual practice, in contrast with hardware which doesn't switch phase each field (like, an SNES).

In any case, I'm not going to cripple the functionality of my VIC20s, period. I like being able to get full functionality of my VIC when connected to my preferred TV sets and monitors. I would have thought it went without saying but apparently not--not all TV sets/monitors even have an S-Video input; my preferred Apple Monitor III doesn't (what would it do with the chroma signal anyway?).

[Alan]

In any case, I'm not going to cripple the functionality of my VIC20s, period. I like being able to get full functionality of my VIC when connected to my preferred TV sets and monitors.

You keep saying things like this. Here's where I'm not understanding you, apparently. How would having S-Video output "cripple" your VIC?

I would have thought it went without saying but apparently not--not all TV sets/monitors even have an S-Video input; my preferred Apple Monitor III doesn't (what would it do with the chroma signal anyway?).

No you were right the first time- it does go without saying. No one is suggesting that you be forced to do the s-video mod. If your monitor of choice doesn't have s-video capabilities, then obviously I would recommend you not do it. Now that should go without saying.