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Movie Cart


rbairos

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11 minutes ago, Thomas Jentzsch said:

AFAIK the MovieCart isn't using an ARM (or similar) chip.

No, but that was not my suggestion. I was simply saying that the 10-sprite-wide display algorithm with PF as BG and colour changes per-sprite that the MovieCart uses would be an interesting system for use in displaying a Mandelbrot image.  "The display format is just begging for someone to write a Mandelbrot program."  To further clarify, I'm not suggesting the MovieCart hardware would do that encoding. It would be an ARM and probably a new bankswitch format, I'd say.

Edited by Andrew Davie
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12 minutes ago, Andrew Davie said:

No, but that was not my suggestion. I was simply saying that the 10-sprite-wide display algorithm with PF as BG and colour changes per-sprite that the MovieCart uses would be an interesting system for use in displaying a Mandelbrot image.  "The display format is just begging for someone to write a Mandelbrot program."  To further clarify, I'm not suggesting the MovieCart hardware would do that encoding. It would be an ARM and probably a new bankswitch format, I'd say.

I see. Not sure how fast a 70MHz ARM can do Mandelbrot calculations. Maybe fast enough.

But how complex would the display calculations become? IIRC there currently is some brute force behind it, no?

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2 minutes ago, Thomas Jentzsch said:

I see. Not sure how fast a 70MHz ARM can do Mandelbrot calculations. Maybe fast enough.

But how complex would the display calculations become? IIRC there currently is some brute force behind it, no?

Well, I'm not proposing 60Hz frame rate, to start with!  One frame/minute would be just fine. I'm just pointing out that the display kernel would be nice to display Mandelbrot. Having said that, the display calculations are not that complex, but yes time consuming. A bit of an exhaustive search going on, but with early-cutoff optimisations. If I had to guess, I'd say maybe 1 frame every 10s might be a goer (including the Mandelbrot bit). But that's just a wild guess.

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18 hours ago, Al_Nafuur said:

 

?

 

That's really cool.
When thinking about 'what next' for movie cart, I investigated the gameboy briefly.
It has 4-shades per pixel, so would be much easier to encode for.
Nice to see someone having built such a nice implementation of streaming video for it.

Also thought about Coleco-vision. Though the resolution would be much better,
the palette is really limited compared to 2600, making for a worse image from what I 
initially gathered.






 

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On 12/30/2021 at 9:09 PM, rbairos said:

So I run a little script when you hit Reset (Erase).
It sets up the length of the timeline, otherwise its left at whatever it was last time.

Are you pressing Reset after loading the new file?
I should make that more automatic.
 

Yes - it needed Reset.  

 

Thank you

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17 hours ago, cbelcher said:

Yes - it needed Reset.  

 

Thank you

I've just updated the toe file so
-Dialog now includes 'Length' info
-Length is updated when you press start, not init.
-Output section labelled 'Encoding'

Cheers.

 

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On 12/29/2021 at 8:08 AM, cbelcher said:

Yes, with a little effort I did find the two chips - from Microchip themselves and the dual port RAM from Digikey. Stock levels were very low.

 

Microchip has the PIC18F47K42-I/P as available to ship Jan 9 2023!

7130LA35PDG does not seem available anywhere either.

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3 hours ago, Fierodoug5 said:

Microchip has the PIC18F47K42-I/P as available to ship Jan 9 2023!

7130LA35PDG does not seem available anywhere either.

I'm currently redesigning the cart to avoid 7130LA35PDG (obsolete dual port ram).
And changing the chip from PIC18F47K42 to dspic33ev series, though that's probably in short supply as well for the time being.

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35 minutes ago, rbairos said:

I'm currently redesigning the cart to avoid 7130LA35PDG (obsolete dual port ram).
And changing the chip from PIC18F47K42 to dspic33ev series, though that's probably in short supply as well for the time being.

 

Haha I've done searches over several days and my feeling was you chose parts made from unobtanium.

Looking forward to the redesign :)

 

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  • 6 months later...

Thanks for asking.
I've been quietly working on V2 off/on over the months.
I had to go with SMD parts in the end, so learned about stencils, drag-soldering etc.
Wasn't as horrifying as I'd imagined.

The end result is probably half the part in costs ( and no obsolete parts), and looks like no cart mods will be necessary (after I add some tab-holes)
(hoping to make it drop-in compatible with a combat cart).
Still 2600 and Flashback2 compatible.

Re-wrote the firmware from scratch as well, so the boot-time is much faster (2 msec if I recall), so no more repeatedly cycling the power switch with baited breath.

Another major improvement is you can just drag-drop the movie file directly onto the SD card.
Version 1, required a special utility to painstakingly transfer the file onto special sectors on the SD card, which made it unreadable with the host PC afterwards.

My goal from here is to add some tab-holes onto the PCB.
Then I'll likely put everything up on open-source again.

If somebody wants to build + sell them that would be ideal.
I'm hoping after these modifications that will be a much more straightforward process.

From there I can concentrate on more software changes like PAL settings etc

Cheers,
Rob.

VNTLUKBZemf8dJssilQmydw76a43qujq_Qsv8Ec3Rba1P5tQ_8Kbw1KOGZDOVb0L34HyfINicjeYU32cP-kRnXzvG9L2z9yuRuM7t2r49wq7NiG9k9O26uTMFcQkReCFCiFnSKTtKb95xvf3UjukhX_qSNL5TeSDC1ZwHHD2WxMSlKpuzt0yJ5MC2Kte-L7mfGhI4D29QOAtKs-M7XD0cZoe-thYMlfS1ZCOLJbyHMaLkTJBvYcIfn1CmtLmGgDwTLEf_00J9ImV9zVfO18N6_drJtOV70gBu54eoXbqqhQenWrTjsgaAbrxliCNvI8ixlbYxAA40WHHxBTEAYT_ORjcKL5QRzDJ5ruuKFAuGnwQmg-SahTjbc5kmhXiHUn7EO02DdCbel7ZtgNqex5nerKfUd-8Z9RtHsUadR9Hae9rJkmiX49oOw7Z_BiINCjRkJvvS24dIcZcqVP1GhqXURWmEODS3dA9wHpu98JGASObeG1cmmpzaNRQAM17kvgyoByDXYp13pX2laordgQDTeCrzN9O1Cy9ajluUgJ89FzeHYvpo-gAkpPzRKwHtOzcytkYx8rTbneg1rOviPu44A_ld5WyTMDtnJlo2Qrgu30RjnEWj39gIublMBeW77W-pDF83-y8GyTeSmTko7YMg7xyvDRt_rUDzlgKGEnrs8w41pvFy79EVzT_PVPRld3a3V0bd0JvfoYajXaHHSKnazlDTDAXw7OfIQEr_ctvouxEr820OnJhUsW3ICtu=w1181-h1574-no?authuser=0



 

Edited by rbairos
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  • 4 months later...


Hardware update:

So, I've been slow working on the tab holes, and experimented with an overseas assembly service.

My 5 test boards just came in today.
Good news is it's crazy cheap to get SMD assembled boards.
Bad news is, the modern easy to find microcontrollers I redesigned around, are now unobtanium as well.
Luckily, I have exactly *1* spare microcontroller to hand-solder into one of these new test boards.
Unluckily,  my tab-holes don't quite work, and need some tweaking. 
I really want to make this 100% drop-in compatible to an unmodified combat cart. Getting close.

Here's a pic showing the evolution so far: (BROKEN LINKS FIXED)

1. Through-hole, (expensive obsolete parts/heavy/requires cart mod and hard to insert/expensive SD card module), but easy to solder.
2. Hand soldered SMD components including SD card section (center screw post preserved)
3. Machine assembled SMD components (and almost drop-in combat compatible), SD card oriented properly + lots of test points for debugging more easily.



No idea if 3 will work or not, but its electrically the same circuit as 2, except some resistor values changed in keeping with their inventory options,
and its a different SD card socket, plus a million little routing path changes to accomodate the tab holes.
I'll hand solder my last microcontroller (yuck) onto the shiny square in the middle right and post an update.


 

moviecart_123_pcbs.jpg

Edited by rbairos
broken picture link
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(Thanks Andrew. Replied.)

 

So good news. 

Despite my best attempts to melt/scorch/warp the circuit board I was able to finally hand solder my last .4mm pitch microcontroller to the board. It is not my favorite activity.  I nearly threw in the towel several times but it miraculously works.

 

The tab holes need adjustment though so the layout needs another iteration before it will slip into an unmodified combat cart.

 

Digikey lists a 52 week delay for the chips but mouser lists 610 in stock right now.  I've nabbed 5 for development but hope they'll still be available once I finalize the design.

 

Cheers.

 

 

20221204_092937.jpg

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  • 2 weeks later...

Great news. The next revision of the boards came in, and it now fits properly into an unmodified combat cart, and inserts cleanly into the cartridge slot as well.
No more clunky heavy carts with cut up insides.

And here it is in action:

https://photos.app.goo.gl/EtMRvqjUrbMGruVw6

Next step. Taking a cue from @ZackAttack to figure out to make the firmware updatable from the sd-card before finally releasing it to the wild.

Cheers.



 

atari_moviecart_combat.jpg

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