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ChildOfCv

ColecoVision diagnostics shield

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15 hours ago, Tursi said:

Nice! Can it test for the ground pin that sometimes gets disconnected and causes issues with some carts? Seems like having a quick verification of that wouldn't hurt.

 

Thanks for the schematic update!

In fact, that is also one of the things the cartridge port add-on was designed to test :)

 

It's just 4 8-bit shift registers.  Both grounds have pull-up resistors on them so they'll read high if disconnected.  The power has a pull-down to read low if disconnected.

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hi @ChildOfCv  great work with ColecoVision diagnostics shield! would it work on a PAL coleco? what differences?
would you sell a ready-to-use version? although it is not the final final version.I already have 4 stacked colecos waiting for a little magic. tnks

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Everything but the external video generation test would work.  The video generation test uses NTSC timings, so it would technically "work" except for the sync problems.  With some effort, the timings could be adjusted for PAL though.  It does not attempt to produce color, it is only to check if a pattern can appear.

SECAM SCART CVs would be different due to the redistribution of external video 

 

I do have "final" PCBs made now.  I haven't made any attempt to sell them though since the casual user would only have use for it, maybe once to diagnose a failed system.  It might possibly help a repair tech though, especially since the chips aren't socketed, so swapping them for a mere test is a chore.

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Exactly, for the technician it is a great tool, so you say all the chips are welded (and heavily welded!) which makes the task quite tedious. I am learning to be able to dedicate myself to repairing the colecos in my region. In Argentina it was a very popular console in the 80s and there are many around. But many unfortunately black screen. I am passionate about repairing them and bringing them back to life.

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Having repaired multiple colecovisions for me and a friend this would be something I would buy for sure, previously I have replaced chips until I found the correct one which is a pain

 

If you do decide to sell any I will be purchasing provided it deals with both pal and ntsc

 

I do have a secam machine that has some issues with video (jail bars displayed when the system warms up) that i havent tracked down unfortunately, this possibly would help

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7 minutes ago, omf said:

Having repaired multiple colecovisions for me and a friend this would be something I would buy for sure, previously I have replaced chips until I found the correct one which is a pain

 

If you do decide to sell any I will be purchasing provided it deals with both pal and ntsc

I have a stack of ColecoVisions that need testing and repair and I too would love to have something like the diagnostics shield for testing.  I liken this to the dead test cart and diagnostics harness that's available for the Commodore 64.  The latter is extremely useful for verifying that everything is working after a repair without having to manually try out a load of different games to make sure all is good.

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Obviously I'm in for one of these should they become available to us hobby techs.

 

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Hmmm.  Looks like I need to order more boards.  I just got the "prototype quantity" of 3.  Sounds like I need a full panel instead.

 

I also noticed while collecting the final BOM that I used way-under-performing filter inductors on the power supply.  3mA probably won't work.  I should increase the footprint size by at least a 100x.  Maybe use the 500mA USB max supply as a guide.  That means I need to increase the footprint size a little.

 

I'll do a tweak there and then order some new PCBs.

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Okay, I assembled the final BOM.  Looks like it will cost $42 in raw materials.  Adding 10% to partially recoup past costs, let's call it $48 + shipping.

 

I also need to consider installing a boot loader on the Atmel so that you don't need the expensive programmer to update it.  Hmmm.... which one though, and how to use it?

 

Edit:  Forgot to account for the ribbon cable connector

Edited by ChildOfCv
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4 hours ago, ChildOfCv said:

Okay, I assembled the final BOM.  Looks like it will cost $42 in raw materials.  Adding 10% to partially recoup past costs, let's call it $48 + shipping.

 

I also need to consider installing a boot loader on the Atmel so that you don't need the expensive programmer to update it.  Hmmm.... which one though, and how to use it?

 

Edit:  Forgot to account for the ribbon cable connector

i would be happy with a 6 pin icsp header, then it can be flashed with a cheap arduino uno clone and avrdude

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On 8/14/2020 at 6:02 AM, Ikrananka said:

I have a stack of ColecoVisions that need testing and repair and I too would love to have something like the diagnostics shield for testing.  I liken this to the dead test cart and diagnostics harness that's available for the Commodore 64.  The latter is extremely useful for verifying that everything is working after a repair without having to manually try out a load of different games to make sure all is good.

Seconded. I would love to automate diagnosis on my stack of ColecoVision machines. There truly are many fragile components on this aging hardware.

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I would also like one of these if made available to purchase to use for my 10 colecovisions sitting in my shop. It would save tons of testing time.

 

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13 hours ago, omf said:

i would be happy with a 6 pin icsp header, then it can be flashed with a cheap arduino uno clone and avrdude

Hmmm.  Looks like the Arduino boot loader is supported by avrdude, and it can use the FT232 for serial transfer rather than bit-banging its extra I/O ports which are assumed to be connected to the ISP pins.  Maybe I'll go that route.

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The latest news is that the new boards are at the "sent to the fab" stage.  They typically get the boards back and tested within a couple of days.

 

In other news, looks like I successfully added a boot loader using MCUDude's MegaCore add-on.  This means you don't need special hardware to upload newer flashes.  It can be done through the USB serial connection.

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9 minutes ago, ChildOfCv said:

The latest news is that the new boards are at the "sent to the fab" stage.  They typically get the boards back and tested within a couple of days.

 

In other news, looks like I successfully added a boot loader using MCUDude's MegaCore add-on.  This means you don't need special hardware to upload newer flashes.  It can be done through the USB serial connection.

excelent news!

@ChildOfCv  were you able to get the PAL version of the BIOS? Here in Argentina the Colecovision (PAL) were sold with an improved BIOS, from the factory the "Coleco screen" only lasts about 3 seconds. Would it be useful if I extract one of the ROMS and read the content and send you the BIN file?

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2 hours ago, Zak said:

excelent news!

@ChildOfCv  were you able to get the PAL version of the BIOS? Here in Argentina the Colecovision (PAL) were sold with an improved BIOS, from the factory the "Coleco screen" only lasts about 3 seconds. Would it be useful if I extract one of the ROMS and read the content and send you the BIN file?

It might be.  I have checksums for about 5 variations of ROM, including aftermarket patches, but... like Pokemon, gotta collect em all!

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4 hours ago, ChildOfCv said:

It might be.  I have checksums for about 5 variations of ROM, including aftermarket patches, but... like Pokemon, gotta collect em all!

 

Not sure if the Argentinian PAL BIOS is the same as the UK/Europe PAL/SECAM BIOS but the latter is attached.  You've likely already got this one.  Not sure what was used in Australia but I suspect it was the same one.

 

There's also my hacked NTSC BIOS which "improves" the title delay, reducing it to 3.3 seconds, to exactly match the PAL title delay.  Also attached.

CBS ColecoVision BIOS OS7 (1983)(CBS Electronics)(PAL-SECAM).rom ColecoVision BIOS OS7 (2019)(Ikrananka)(NTSC)[3.3s Title Delay].rom

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28 minutes ago, Ikrananka said:

 

Not sure if the Argentinian PAL BIOS is the same as the UK/Europe PAL/SECAM BIOS but the latter is attached.  You've likely already got this one.  Not sure what was used in Australia but I suspect it was the same one.

 

There's also my hacked NTSC BIOS which "improves" the title delay, reducing it to 3.3 seconds, to exactly match the PAL title delay.  Also attached.

CBS ColecoVision BIOS OS7 (1983)(CBS Electronics)(PAL-SECAM).rom 8 kB · 2 downloads ColecoVision BIOS OS7 (2019)(Ikrananka)(NTSC)[3.3s Title Delay].rom 8 kB · 2 downloads

Your BIOS is also fully compatible correct?

 

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3 hours ago, -^CrossBow^- said:

Your BIOS is also fully compatible correct?

 

Just a single byte controls the title screen delay and so there is only a single byte's difference between the stock NTSC BIOS and my hacked NTSC BIOS.  So unless the game/program running on the ColecoVision checks the value of this byte and uses it in some way, then yes my hacked BIOS would be fully compatible.  I am not aware of any game/program that checks and uses the byte in question.  More details of my BIOS analysis and hack can be found here.

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45 minutes ago, Ikrananka said:

Just a single byte controls the title screen delay and so there is only a single byte's difference between the stock NTSC BIOS and my hacked NTSC BIOS.  So unless the game/program running on the ColecoVision checks the value of this byte and uses it in some way, then yes my hacked BIOS would be fully compatible.  I am not aware of any game/program that checks and uses the byte in question.  More details of my BIOS analysis and hack can be found here.

I was asking because it is well known that some games do NOT work with the current No-Delay BIOS that is all over the place. Even the no-delay BIOS that console5 sells still has the compatibility issues with games like Sewer Sam. I thought I had seen mention of a no-delay bios or similar that didn't have these game compatibility issues. Would be nice to let Console5 know this so they could a different rom to burn their BIOS chips with vs the common one now.

 

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11 minutes ago, -^CrossBow^- said:

I was asking because it is well known that some games do NOT work with the current No-Delay BIOS that is all over the place. Even the no-delay BIOS that console5 sells still has the compatibility issues with games like Sewer Sam. I thought I had seen mention of a no-delay bios or similar that didn't have these game compatibility issues. Would be nice to let Console5 know this so they could a different rom to burn their BIOS chips with vs the common one now.

 

The issues with the no-delay BIOS were the very reason that I investigated the title delay byte option.  I've now changed the BIOS in all my CVs to the 3.3 second delay rather than the no-delay (fire skip) BIOS to avoid those issues.  I'll contact Console5 so that he is aware there is an alternative.

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1 hour ago, Ikrananka said:

I'll contact Console5 so that he is aware there is an alternative.

Email sent.

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4 hours ago, -^CrossBow^- said:

I was asking because it is well known that some games do NOT work with the current No-Delay BIOS that is all over the place. Even the no-delay BIOS that console5 sells still has the compatibility issues with games like Sewer Sam. I thought I had seen mention of a no-delay bios or similar that didn't have these game compatibility issues. Would be nice to let Console5 know this so they could a different rom to burn their BIOS chips with vs the common one now.

Looks like in the Sewer Sam case, it's precisely because of the fire-skip addition.  The game makes calls into the middle of the start delay function with its own delay counter values in order to save on its own code.  In at least one place, it expects the 'b' register to be unharmed during the call.  The fire button check destroys the 'b' register.

 

Also, the fire button check adds a little bit more time to the delay if you wait it out, because it doesn't adjust the countdown values accordingly.  So if a game is timing-critical and calls that function chunk, it could end up waiting juuuust a little bit too long.  And on the other extreme, it may return without delay if you are pressing the fire button at the times it makes those delay calls.

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@ChildOfCvjust some general feedback based upon your shared project folder with the schematics and whatnot.

 

There appears to be some errors with the PAL SCART board project, there seems to be multiple R180's and R181's also the pcb layout is for a NTSC Coleco, i did try importing a new netlist but errored because of the multiple resistors.

 

i did try and fix that by giving them some name appendages but it gave me more issues after, so gave up.

 

this is only because i spent most of the week trying to self learn kicad which i have learnt a lot but there's still a lot missing like multiple schematics and hierarchy etc

 

thought i would have a play with a more complex project than my own one sheet jaguar joypad to coleco joypad converter project, which is coming along quite well now :)

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