600XL factory bodge/fix?

[deffroe]

Evening all,

I started to disassemble my new 600XL this evening.  Signs were saying it is untouched, case screws were quite stiff and all had hole debris.

Parted the 2 halves of the case to view the keyboard connector...research keyboard connector, sorted.

Noticed the keyboard had a protective screen over lower half around connector and a rubber bung on top of joystick port, is this typical factory? And all the tape? Not seen any 800XL's like this before.

Struggled to remove motherboard from case, pesky hidden screw🥴.

While inspecting the motherboard saw the bodge/repair, it kind of looks factory but also looks kinda crude, a track has been gouged and the resistor/cap added.  This is all under and to the RF modulator.  

Does this look factory or a user bodge?

 

When I briefly tested yesterday I thought there was no RF signal but did a signal scan and it's working.  Both RF and composite are quite clean with RF being a softer image.

 

Edited August 25, 2023 by deffroe

[deffroe]

Blimey, submit by mistake...here is RF, composite and full board photos...

 

[Beeblebrox]

@deffroeYup, I've seen loads of 600xl with that bodge under the board. Very typical. 

 

To sharpen the image remove c109. Makes a big difference. 

 

Are you gonna add chroma? I always do and on svideo with c109 removed the 600xl video output is one of the best and cleanest outputs of any of the models.

 

Edit: adding chroma is easy btw (image courtesy of FJC's video on the subject). 

 

 

Edited August 25, 2023 by Beeblebrox

[deffroe]

13 minutes ago, Beeblebrox said:

@deffroeYup, I've seen loads of 600xl with that bodge under the board. Very typical. 

 

To sharpen the image remove c109. Makes a big difference. 

 

Are you gonna add chroma? I always do and on svideo with c109 removed the 600xl video output is one of the best and cleanest outputs of any of the models.

 

Edit: adding chroma is easy btw (image courtesy of FJC's video on the subject). 

 

 

Not decided which way to go yet, got a sophia spare as an option but also could go UGv or Spectre for now.  Like the idea of a HAVO option in the future and VBX*.  Got 64K on its way.  So that and a cleanup for now.

[deffroe]

31 minutes ago, Beeblebrox said:

I've seen loads of 600xl with that bodge under the board. Very typical. 

Thats good to know, definitely looking more like an untouched machine.

[Beeblebrox]

52 minutes ago, deffroe said:

Not decided which way to go yet, got a sophia spare as an option but also could go UGv or Spectre for now.  Like the idea of a HAVO option in the future and VBX*.  Got 64K on its way.  So that and a cleanup for now.

Yup defo upgrade to 64K. I do this:

I've installed VBXE in lots of 800XLs and a few XEs. I've only installed VBXE in a 600XL once.

 

Sophia 2 is great. I've installed quite a few in 600XLs. Bare in mind if you wanna avoid cutting the casing you can use a DVI mount which is 3D printed. It can include the audio jack as well. Then all you need to do is extend the ribbon cable or buy a longer one to stretch, then take the audio from the PCB/or the Din5 audio pin from the board to the new jack.

 

UGV is something I've installed in a good few XEs and a few 800XLs. Not installed one in a 600XL because after adding Chroma and removing C109 the output is so good on S-video I didn't need to upgrade to UGV, or SpectreAv for that matter.

 

Let me know if you want me to print you out a Sophia 2 PBI DVI mount for free. Happy to.

Edited August 25, 2023 by Beeblebrox

[xrbrevin]

3 hours ago, deffroe said:

a rubber bung on top of joystick port, is this typical factory?

yes ive seen this before and thought it was a bit mysterious..

[Beeblebrox]

12 minutes ago, xrbrevin said:

yes ive seen this before and thought it was a bit mysterious..

I've only really seen the rubber bung on the 600XLs. I think it's actually a rubber foot. Useful as a spare.

 

Maybe in the factory it was actually put there as a spare foot?  (You know how you get a shirt with a little tag and spare button enclosed. Same thing perhaps?

 

Or maybe it's to help hold the joystick port in place if they felt at the factory with the 600XL that it needed it. (Can't see it myself)

 

TBH I am just hypothesizing here.

 

This was a 600XL I had a couple of years back where I happen to have snapped a pic at the time, (rubber foot stuck to top of the first Joystick port which you can just make out):

 

[+x=usr(1536)]

3 minutes ago, Beeblebrox said:

I've only really seen the rubber bung on the 600XLs. I think it's actually a rubber foot. Useful as a spare.

 

Maybe in the factory it was actually put there as a spare foot?  (You know how you get a shirt with a little tag and spare button enclosed. Same thing perhaps?

 

Or maybe it's to help hold the joystick port in place if they felt at the factory with the 600XL that it needed it. (Can't see it myself)

 

TBH I am just hypothesizing here.

Adding to the hypothesising: it always struck me as being a support to prevent the keyboard caving in when someone stabbed a console key with the might of a thousand piledrivers 

[Beeblebrox]

10 minutes ago, x=usr(1536) said:

Adding to the hypothesising: it always struck me as being a support to prevent the keyboard caving in when someone stabbed a console key with the might of a thousand piledrivers 

True.

 

Maybe it's in the event of an earthquake it increases the chances of the machine remaining intact?!!

[deffroe]

10 hours ago, Beeblebrox said:

Sophia 2 is great. I've installed quite a few in 600XLs. Bare in mind if you wanna avoid cutting the casing you can use a DVI mount which is 3D printed. It can include the audio jack as well. Then all you need to do is extend the ribbon cable or buy a longer one to stretch, then take the audio from the PCB/or the Din5 audio pin from the board to the new jack.

Is the PBI still accessible/usable when the mount is installed?  The Sophia 2's that I've installed have replaced the modulator, I add a 3.5mm jack for dual mono audio(easily adapted for stereo upgrade). Would rather not cut into the cases but the results from Sophia kinda make it worthwhile.  But if pbi is still usable I'll happily take up your offer.

Regarding svideo, I don't have that connector on my tv.  I'm limited on space so my screen is shared between PC and Atari.

 

[Beeblebrox]

2 hours ago, deffroe said:

Is the PBI still accessible/usable when the mount is installed?  The Sophia 2's that I've installed have replaced the modulator, I add a 3.5mm jack for dual mono audio(easily adapted for stereo upgrade). Would rather not cut into the cases but the results from Sophia kinda make it worthwhile.  But if pbi is still usable I'll happily take up your offer.

Regarding svideo, I don't have that connector on my tv.  I'm limited on space so my screen is shared between PC and Atari.

 

So as you probably know already the order of quality for stock A8 video outputs is this:

 

RF - bad (only as a last resort)

Composite - acceptable but you get bleeding, artefecting, blooming and blurring etc as Chroma and Luma are mixed together in a composite setup and there is lots of noise.

S-video - the best as Chroma and luma are on separate lines and also having a double sheilded S-video cable helps massively to eliminate cable cross talk.

 

So even if you don't have an S-video connection on your TV, using composite from the outset means the image and signal quality is worse coming out of the A8.

 

So to get a good image you can still hook up Chroma in the 600XL, remove the C109 ceramic cap, and then take your quality S-video signal from your Din5 on the Atari 600XL via a Sin5 to S-video cable, but the end of that S-video cable could go into any one of the following to convert to your TV input:

 

S-video to Scart:

 

Or a converter box (where this one converts your S-video to HDMI and a separate audio):

 

Obviously some adapters/converters are better than others, but you get the gist.

 

You need to get the best quality signal out of the A8 in the first instance and if you haven't got any internal video upgrades (UGV, SpectreAV, etc), producing a clean image from the outset and are just using the RF or AV composite, you won't have the best visual experience.

 

If I plug my stock or even UGV A8s into my TV using a composite cable, then do the same with an S-video cable, (providing the latter is a well shielded one), the difference in image quality is massive.

 

Case in point here is my 600XL (with Chroma hooked up and C109 removed) on firstly an AV composite cable, and then secondly on an (unshielded) S-video cable (as my Hercules double shielded one is broken):

 

AV composite, (bleeding, artefacting, blooming and blurring as luma and chorma are mixed)

   

 

S-video cable (one that is unshielded - not ideal but still a great image; no bleeding, blooming or artefacting and much sharper):

   

 

It's worth noting artefacting for NTSC machines was used to create colour in some games, (Ultima series for example). However for PAL systems the artefacting is (IMHO) horrible:

 

Amaurote on a PAL AV composite with artefacting:

 

 

and on S-video:

 

Bottom line - S-video rocks on a stock 600XL with chroma hooked up to get a signal in the first place, and c109 removed to sharpen the image further.

 

Sophia 2 DVI PBI mount

 

Yup so the PBI is blocked as the DVI 3D mount is a modified cover to replace the stock one. However if you use a long ribbon cable and long wires for the audio cable, then you can pop it out whenever you want to use the PBI - so long as there is enough slack. I only ever use the PBI for my Syscheck 2.1 and that is really only for diagnosing A8s. So in my case I'd much rather have this and not cut the case. I know you can do a really nice job with mounting a DVI in place of the RF modulator and cutting a hole in the case for it. (I've done this for my 800XL which has Sophia 2 and VBXE installed). However I am in the habit of shifting upgrades between A8s, so the less modding of cases the better. My Sophia 2 has moved homes at less three times between XLs and XE's I own heh heh.

 

Here is the DVI PBI mount with - in this case - my stereo RCA jack addition. (So for mono you just have the single jack:

 

  

 

 

Here is the mount before it has any audio jacks mounted:

 

 

Edited August 26, 2023 by Beeblebrox

[_The Doctor__]

wow, that's terrible and shows a serious signal/cable issue along with display adjustment settings on sear your retina mode. Certainly not adjusted well at all. What kind of display was that? Was there oil or grease Vaseline hazing the edges of the camera lens. My eyes want to leave my skull. You have injured us sir! 😮

Such blurring, insane! I'm going to go slap an optometrist now. Ouchie!

Edited August 26, 2023 by _The Doctor__

[deffroe]

Making up an svideo cable and completed chroma mod this morning, couple of frights along the way, I tested with partially complete svid cable and RF.. powering on did the little prayer to the Atari god for it to work.  No signal from svideo and now RF is dead😱 Always helps to plug in the power👍😁.

So got an svideo signal but it's a bit rough, photos attached of mod, cable and screen quality.

I followed flashjazzcat video guide except I used a 22uf cap, after reading comments and that it's a much slimmer cap than the 220uf that I have.

 

Would the rough video be because the cable is incomplete e.g metal casing not yet install, so weaker grounding, or having made a mistake elsewhere?

[Beeblebrox]

Quite possibly your cable is introducing issues. 

 

The 22uf cap isn't something I could comment on. It is optional so you can remove. I always use a 220uf.

 

Have you removed c109 ceramic cap? 

[deffroe]

yes c109 removed, big ugly ceramic disc type.

[Beeblebrox]

13 minutes ago, deffroe said:

yes c109 removed, big ugly ceramic disc type.

Cool. 

So yeah I suspect your cable is introducing some noise.  As I say I've worked on many PAL 600XL's and they always have great stock video, so the cable is most likely something you wanna nail. 

 

Edit: just to check what type of 75ohm resistor are you using there? 

Edited August 27, 2023 by Beeblebrox

[TGB1718]

Hard to tell from your photo, but is your cable just a screen around both wires or individual screens

for each wire, individual screens work best with this.

 

I single screen will still allow some cross-talk between the wires, it just shields the wire from outside

interference and of course prevents the S-Video signal from radiating to other components/systems etc.

 

I used an S-Video cable from an old camera, cut one end off and put the DIN plug on, those old cables

tend to be individually screened.

Edited August 27, 2023 by TGB1718

[deffroe]

2 hours ago, TGB1718 said:

Hard to tell from your photo, but is your cable just a screen around both wires or individual screens

for each wire, individual screens work best with this.

Cable make up is individual pvc insulated conductors for chroma, luma, chroma gnd and luma gnd with a bare gnd wire and foil wrap. It is just a svideo cable that I cut the end off.

 

Edit: apologies, I'd typed this msg earlier today on my phone.

Edited August 27, 2023 by deffroe

[deffroe]

3 hours ago, Beeblebrox said:

Edit: just to check what type of 75ohm resistor are you using there?

The resistor is a 1/4w.

[deffroe]

There is a a bright yellow and pale yellow conductor, signal grounds.  Black and red going to pins of socket are chroma and luma.  The bare ground strands have a bit of black heat shrink and joined to the signal grounds.

[flashjazzcat]

4 hours ago, deffroe said:

I followed flashjazzcat video guide except I used a 22uf cap, after reading comments and that it's a much slimmer cap than the 220uf that I have.

Even that is overkill (I learned after the event, even though my own machine still has an electolytic cap fitted and I'm happy with it), and most 600XLs which come through my hands don't need any cap at all. If they do, a low-rated ceramic will usually do the trick.

[_The Doctor__]

the cable does not appear to have individual shielding at all, I see no braid or weave, each signal should have a sheath of shield around it.

[deffroe]

Ordered a new 'fully shielded pure copper' svideo cable.  Will make that up when it arrives.

[Beeblebrox]

@deffroeI recall wanting to make up my own cable a couple of years back. Because I wanted to make a double shielded cable as close to the hercules workshop one as possible I spent ages trying to source a double shielded cable suitable. Never had any luck. I only found suppliers who sold single shielded or not shielded at all. In the end I just bought the Hercules workshop one. A couple of years on I might try and make my own. Can you let me know where you sourced your shielded cable from? (I assume it's single shielded?) 

 

Also worth noting Mytek found another method which involves buying premade cables and couplings. I followed it and had mixed results. 

 

See here:

 

 

 

 

Edited August 27, 2023 by Beeblebrox