US 600XL & UAV, composite or luma/chroma

[bfollowell]

25 minutes ago, Mazzspeed said:

Can you add a monitor port to the 600XL?

 

Yes, as I said, I did that with mine. The motherboard actually has the pads for the DIN under the channel selector switch. You remove the channel selector switch, cut a trace, or maybe it was two, install the monitor port and solder the wires to it. I bought a UAV and the DIN port from Marlin at The Brewing Academy and the instructions are included. The plus was that, depending on how you install, you can keep the original modulator output as well, though it will only output on one channel and you can no longer select which channel to send it to since the channel selector switch is no longer there. But with a UAV and monitor port, I'll never really use modulator output, nor would you if you're purchasing an NTSC unit. You do have to drill and enlarge the hole in the case for the monitor port though.

 

[BillC]

19 minutes ago, Mazzspeed said:

Hmmm. OK.

 

So if I can just add the port, that would be beneficial until I get the funds for a UAV or similar.

 

EDIT: As I really want a Sophia 1/2.

The NTSC version of the 600XL removed many components for the video circuit, not just the monitor jack, leaving just enough to feed the RF modulator. Without these missing components(3 transistors plus associated resistors/capacitors/inductors)there are no chroma/composite signals, only luma.

 

The UAV uses the GTIA signals without amplification, it can replace the 4050 buffer chip(this disables RF output) with its outputs connected directly to the monitor port.

 

[Mazzspeed]

1 minute ago, BillC said:

The NTSC version of the 600XL removed many components for the video circuit, not just the monitor jack, leaving just enough to feed the RF modulator. Without these missing components(3 transistors plus associated resistors/capacitors/inductors)there are no chroma/composite signals, only luma.

 

The UAV uses the GTIA signals without amplification, it can replace the 4050 buffer chip(this disables RF output) with its outputs connected directly to the monitor port.

 

Ugh...That sucks.

 

So if I look at a US model and think it's cheaper, I need to consider the cost of a UAV. So it may be cheaper to get a PAL model.

[BillC]

18 minutes ago, Mazzspeed said:

Ugh...That sucks.

 

So if I look at a US model and think it's cheaper, I need to consider the cost of a UAV. So it may be cheaper to get a PAL model.

That's an option if you have a PAL capable monitor, there is another thing to consider though.

Do you run any software that only works on NTSC systems?

There is NTSC software(only games?) that use artifacting, which is only available with NTSC composite/RF output.

Edited January 31, 2021 by BillC

[Mazzspeed]

32 minutes ago, BillC said:

That's an option if you have a PAL capable monitor, there is another thing to consider though.

Do you run any software that only works on NTSC systems?

There is NTSC software(only games?) that use artifacting, which is only available with NTSC composite/RF output.

I am aware of this and have been carefully considering it. When it comes to the C64, PAL is the system to get as there's simply more software. I'm not too sure this is the case regarding the A8. The other thing is: Converting an NTSC C64 to PAL is easy of you have the PAL VIC-II (I know, I've done it). This doesn't seem to be the case regarding the A8.

 

I think many NTSC games were ported to PAL on the A8, but the colours were munted compared to native NTSC?

[BillC]

16 minutes ago, Mazzspeed said:

I am aware of this and have been carefully considering it. When it comes to the C64, PAL is the system to get as there's simply more software. I'm not too sure this is the case regarding the A8. The other thing is: Converting an NTSC C64 to PAL is easy of you have the PAL VIC-II (I know, I've done it). This doesn't seem to be the case regarding the A8.

 

I think many NTSC games were ported to PAL on the A8, but the colours were munted compared to native NTSC?

I know the A8 has PAL specific ANTIC/GTIA ICs, I believe other changes would be the OS/clock crystal?

I've never done it and don't know how involved it is.

Several AA members have converted the 1200XL, an NTSC only model, to PAL.

 

[Mazzspeed]

21 minutes ago, BillC said:

I know the A8 has PAL specific ANTIC/GTIA ICs, I believe other changes would be the OS/clock crystal?

I've never done it and don't know how involved it is.

Several AA members have converted the 1200XL, an NTSC only model, to PAL.

 

From what I've seen I think the PAL A8 has an additional crystal/clock circuit?

Edited January 31, 2021 by Mazzspeed

[+hloberg]

6 hours ago, bfollowell said:

 

I went to college for computer/industrial electronics and worked as a bench tech my last year in college before moving over to the auto industry for immensely better pay and benefits, but that was thirty years ago. I just picked up my first in almost three decades soldering iron and rework station a year ago, so I'm far from a pro. I'd consider myself upper mediocre. Keeping all that in mind, the entire monitor port project (switch box removal, monitor port install, UAV install) only took me about thirty minutes, not counting disassembling the 600XL. It really wasn't that bad at all so, unless you have zero soldering skills, I wouldn't be too scared off at the prospect of tackling this project. Now, no insult to @hloberg, because it isn't for everyone, and even the best of us can have an off-day, but this really was a breeze of a project.

 

None taken. I think I just soured on the board because of the problems. Which is why I'm setting the thing aside for a while to get a better perspective. I've done some fairly complex soldering so I don't doubt my skills and if I had just got the drop in board it would have been a breeze. Then it's just pulling the switch, popping the chip out and soldering 2 wires for the sound and 1 wire for the color (all those went perfectly). There are already and area for the socket so soldering that is easy. 

Resting on it I might just order a complete UAV and call it even. I think I just got a bum board. But since I soldered on it, can't prove it. If I get a pre-made board and a problem then I can get a fix.

[alortegac]

Hi!
in related topic,   I recently picked up a 600xl in bad shape which I restored to working condition. 

 

I installed  an UAV but I am getting vertical jail bars only on 1/2 the screen.

 

any thoughts? 
 

thanks in advance. 

[+mytek]

3 hours ago, alortegac said:

Hi!
in related topic,   I recently picked up a 600xl in bad shape which I restored to working condition. 

 

I installed  an UAV but I am getting vertical jail bars only on 1/2 the screen.

 

any thoughts? 
 

thanks in advance. 

You likely have a video cable without individually shielded wires. Jail bars are caused by the chroma cross-talking with the luma signal. Or in other words chroma is bleeding into the luma line due to a poorly made video cable. The bars are actually the representation of the color clocking as interpreted by the luminance input on your TV, with some TVs being worse than others in this regard.

 

I go into more detail about what cables not to use here...

 

[alortegac]

I tried all the cables in my box. Good quality. I only get the jailbars with this machine. 
 

may there be another possibility reason?

 

 Thanks a lot! 

[+mytek]

2 minutes ago, alortegac said:

I tried all the cables in my box. Good quality. I only get the jailbars with this machine. 
 

may there be another possibility reason?

 

 Thanks a lot! 

 

Hmm... those look pretty widely spaced, so it's something at a lower frequency than typical jail bars. I also just picked up on the fact that you said it only happens across 1/2 the screen, so this is definitely unique. As to what's causing it, I'm now drawing a blank