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Sinjinhawke

Cartridge Port Conundrum

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I have a original Intellivision that mostly works.  The oddity I am seeing is that it won't run cartridges that are using the LTO style shell.  I have tried all the different original 125 style carts except Congo (don't have it) and several homebrews like Missile Domination, Astro Invaders, B.C.'s Quest and BSG Space Battle and they all seem to work fine.

 

However if I use an LTO, Rick Dynamite, Old School, the BSR Releases or anything in those shell types I just get a solid colour screen.  The one exception I found so far is Maria worked but not Fantasy Puzzle.

 

What do you think could be causing this unit to be a cartridge snob?  They all work fine in my other units.

 

Didn't realize I posted this in Programming.  That was not intended.  I will repost in the main forum.

Edited by Sinjinhawke
Admitting my posting error

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What type of system is it?  If there's a firmware issue on my boards, I can try to address it.  

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In the early LTO releases, I remember that sometimes you had to hit the reset button a few times, although it didn't happen all the time.  Could that be it?

 

   -dZ.

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LTO Flash and the BSR releases have modern firmware.

 

The earliest JLP boards behave more like dumb ROMs, and so require manual reset about as often as dumb ROMs.  I tested this with a couple original Mattel boards, and JLP.  A simple power cycle required hitting reset afterwards a certain fraction of the time.  ISTR the Mattel boards required reset slightly more often than JLP.

 

I revised the JLP firmware to try to force a reset on power-up, to work around power-up glitches.  With that change, JLP boards didn't require a manual reset in my power-cycle test.  That change has been in the firmware for a very long time now: 8 or more years, I think.

 

Early JLP builds didn't have it (early 2012 or before), but I believe it was in the firmware by the time Christmas Carol was ready for production.

 

Whatever issue Sinjinhawk is reporting sounds different. 

 

@Sinjinhawke, some quick questions:

  • What type of Intellivision? Original 2609, Intellivision II, System ///, SuperPro? Something else? (Tandy, Sears, French SECAM, Bandai...)
  • Do you get a solid color screen that sits still, or does it flicker periodically (about once per second)? 
    • That flicker (if you see it) is the reset code in the firmware trying to make things healthy.
    • What color screen do you get?
    • If it's not solid color, what pattern do you see? Do you get a black screen with hot pink vertical stripes, for example?
  • Have you tried putting an Intellivoice or ECS between the cart and the Intellivision, to rule out cartridge connector or shell fitment issues?

 

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11 hours ago, Sinjinhawke said:

Didn't realize I posted this in Programming.  That was not intended.  I will repost in the main forum.

FWIW, I only saw this because you posted it in the programming forum.   🙂

 

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It’s an original.  It’s a solid colour that just sits there.  I’m using a voice module with the LTO.  I’ll try the ECS tomorrow.  

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6 hours ago, intvnut said:

LTO Flash and the BSR releases have modern firmware.

 

The earliest JLP boards behave more like dumb ROMs, and so require manual reset about as often as dumb ROMs.  I tested this with a couple original Mattel boards, and JLP.  A simple power cycle required hitting reset afterwards a certain fraction of the time.  ISTR the Mattel boards required reset slightly more often than JLP.

 

I revised the JLP firmware to try to force a reset on power-up, to work around power-up glitches.  With that change, JLP boards didn't require a manual reset in my power-cycle test.  That change has been in the firmware for a very long time now: 8 or more years, I think.

 

Early JLP builds didn't have it (early 2012 or before), but I believe it was in the firmware by the time Christmas Carol was ready for production.

 

Thanks for the details.  Yes, I do recall that issue on the very early test builds.  I also recall that you said it was fixed, so it seems like it shouldn't be the same issue.

 

Quote

Whatever issue Sinjinhawk is reporting sounds different. 

I don't know if you saw in the duplicate post on the regular forum, but he confirmed that hitting reset fixes it, so it seems related -- not that it's an LTO-specific issue, but a "dumb ROM" issue.

 

Edited by DZ-Jay

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Are there any timers, NE555, capacitors or similar inside the Intellivision that could have gone bad, so some games that are fast on initializing are border cases for the system being ready to boot without pressing the reset button? I have a very vague memory of some VICs that took very long to count its memory on boot and it was some aged component. If Joe has tested the LTO hardware and firmware on plenty of systems (both directly and their customers) and it usually works, it might be a straw to grab?

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8 hours ago, Sinjinhawke said:

It’s an original.

I assume that means "original Intellivision I console."

Quote

Hitting reset does indeed get the game working.  I didn't try this because I have the console open and I need to stick something in to press down on the reset.   Much appreciated.  

Quote from the other thread.

 

My guess is that the reset capacitor needs replacing.  If this is truly an Intellivision 1 system, then the capacitor you're interested in is C26, which is listed as a 1µF capacitor, 20V, +/-20%.  I got this from the schematic and service manual linked here.

 

What's likely happening is that the capacitor itself has dried out, and so the reset signal hops up too quickly.  Simple ROM designs may cope with that, but my firmware-based boards need a little more time to sync up. (I suspect Intellicarts and CC3s will have similar issues.) JLP and LTO Flash will detect when they've lost a "reset race" by pulsing the reset input.  But, if that capacitor is just acting like an open circuit, then that pulse may not make it through.

 

C26 should be the capacitor right next to the reset button.  While this picture is from a System /// board (since that's what I had handy), this capacitor hasn't moved since the Intellivision 1, from what I can tell.

 

PXL_20210310_130420437_2.thumb.jpg.29dbeef61fcf968c1888f6fa58a00545.jpg

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3 hours ago, carlsson said:

Are there any timers, NE555, capacitors or similar inside the Intellivision that could have gone bad, so some games that are fast on initializing are border cases for the system being ready to boot without pressing the reset button? I have a very vague memory of some VICs that took very long to count its memory on boot and it was some aged component. If Joe has tested the LTO hardware and firmware on plenty of systems (both directly and their customers) and it usually works, it might be a straw to grab?

It's most likely the reset capacitor.  If the system comes out of reset a little too fast, I'll lose that race.  Ordinarily, the cart can pulse Reset and run the race again in the off-chance it loses the race.  But, if the capacitor is totally gone, then the race is likely super fast and the cart can't ask to run the race again.

 

LTO Flash! also uses the reset input pin to start the game once it's loaded, to try to give as close to "Just powered on"/"Just hit reset" environment to the game as possible.  I know with TutorVisions and TutorPros, you have to hit the actual reset button to start the game after it loads.  Or, at least you did. I don't remember if I added code to still try to start the game in the absence of hardware reset on TutorVision/TutorPros or not.  I'm not even sure what's wrong with the TutorVision/TutorPro reset input pin.  It's actually there, and actually wired to an RC circuit, and it actually doesn't do what you want it to do.  (From what I recall on TutorVision machines, you're hitting reset for everything for everybody, not just LTO Flash! or JLP boards.)

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Cool! While I'll admit I'm mostly barking, at least I wasn't aiming at the completely wrong tree. Now let's hope that Sinjinhawke's capacitor cat comes down from the tree and can be replaced.

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I can order some replacements.  Replacing capacitors is a whole lot easier than desoldering IC's to put in a socket.  I have a lot of dead boards here I can harvest the capacitor from until I get some modern replacements delivered.

 

On the LTO I do have to hit reset again after the game has loaded for it to actually play so it sounds like the issue I am having.

 

I have a lot of new ceramic capacitors handy but no electrolytic ones unfortunately.  Console 5 cap kit I guess.

 

Thank you

 

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It seems sometimes you can replace an electrolyte with a ceramic, though you would watch out for ESR. Perhaps better to wait for the right kind, plus that 1 uF ceramics apparently is on the upper end of its range.

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2 hours ago, carlsson said:

It seems sometimes you can replace an electrolyte with a ceramic, though you would watch out for ESR. Perhaps better to wait for the right kind, plus that 1 uF ceramics apparently is on the upper end of its range.

I'm less concerned about ESR for something like a reset pin.  Ceramic isn't polarized—at least, I don't think I've encountered polarized ceramics—which is also nice.

 

The main thing is making sure the capacitance is high enough that the reset low-to-high transition does what it's supposed to do.

 

1µF does sound high for a classic ceramic disc capacitor.  But I wonder whether that's mostly a cost thing?  For something like re-capping an old PCB, we're not as worried about saving 5 - 10 cents per capacitor as Mattel would have been in 1980.  Looking at Mouser's selection, it seems we have a number of options in ceramic, but they're pricey.  (Dunno if that search link will work, but I'll try anyway.)

 

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Yes, the Mouser link converts properly for respective country which can't be said about every other website that exists in localized versions and demands you to follow along. I didn't think he'd order a different kind of component than it takes, but if he had a bag on hand it might just as good as desoldering an equally old capacitor from another broken Intellivision. If he anyway needs a number of components, it probably is most economical to order everything at once.

 

Generally speaking, it might be good advice in case others experience similar issues with the latest games and utility carts, as all consoles are roughly equally old and may exhibit the same issues.

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Yeah none of my ceramic are high enough if I understand the conversion correctly.  I have 6 or 7 boards here so can quickly pull one of those and try it.

 

Console 5 kit $12 looks like it includes some capacitors for the power supply.  Might be a good idea to have some recent versions of those handy.

And they also seem ok with ceramic for C26.

image.png.eb09f2b9bc3a6df52af9b94250142cbd.png

Kits now include a ceramic cap to replace the 1uF non-polar cap C26

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Swapped in a capacitor from a dead board and issue resolved.  No longer have to hit reset for a cart to appear or finish loading from the LTO.  Excellent diagnosis. 

 

Someone definitely opened this system before, there is no cover on the RF box.  Most of the tabs were soldered as well making it a pain to open.

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