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Create and burn eproms for standard Jaguar 2 chip cartridges

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I believe they are 1uf. Digikey sells 500 for $35.

 

Actually have marked as 104 -> 10 + 0000 zeros -> 100.000 Picofarad -> 100 Nanofarad -> 0.1 Microfarad

 

This is the standard value of "decoupling capacitors" for the ic's. :)

Edited by santosp
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Hi all.

 

I know this is an old post but I need a bit of help. I'm new to all this but I have had a GQ-4X programmer for sometime but never used it.  I would like to try and repair a few of the games I have bought as some of the gold connectors have come of the cart.

 

My idea is to unsolder the 'HI' & 'Lo' eproms and solder them back on to a donor board.

 

But if I was to replace the eeprom Memory and/or 93C86 or 93C66 ram eeprom (as mentioned in the tutorial) what information do I need to write to those chips?

 

Thanks

Edited by namrood

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I went through the entire thread but didn't see it mentioned other than not requiring to be closed but what exactly are the C2/C3 spots for?

 

Some carts are closed and others are open and while it doesn't seem to matter in the end, would still like to know why or what the actual purpose of these are for.

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They're extra decoupling capacitors to stabilize the power delivery to the chips. I guess Atari found out that it worked fine without them and saved a few cents by removing them.

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Posted (edited)

Just wanted to post a helpful note on this thread about the EEPROMs (The save-game flash, not the big chips with the read-only game data).  There's lot's of info out there noting you should use the 93c46/93c66/93c86 chips as appropriate for the game you're building, but it is rarely noted (Found some references in the Rebooteroids public beta thread and a few other buried references) that there are two (Well, three. I'll get to this.) variants of all these chips: one with 8-bit and the other with 16-bit data organization.  Jaguar expects the flash organized as 16-bit words, as noted here: https://www.mulle-kybernetik.com/jagdox/cartridge.html.  Look at the datasheet before you buy, and be sure you're getting the right memory organization variant.  You can also get these chips in a variant that can support either mode depending on the value of an "Org" pin on the chip (Pin 6 on the 8-pin DIP Jag carts use), and this pin is floating on the Jaguar cartridge PCBs, so if you have one of these, just short pin 6 to pin 8 (VCC) to select 16-bit mode (Be sure that's the right value for your particular chip of course).  On the chips I bought, pin 7 was also a write-protect bit, and had to be shorted to VCC as well to enable writes at all, as this pin also floats on the Jaguar cartridge PCBs.  I just laid a bit of the capacitor leads that I snipped off after soldering those across all 3 of these pins and soldered it down to accomplish this.

 

As usual, one of @Matthias's tools is a huge help here:  If you have the right EEPROM and have it configured correctly, his EEPROM browser should auto-detect it and be able to manipulate the data on it.  If you made a mistake somewhere, it won't report that the chip type was "detected", and/or you won't be able to manipulate the data.  Of course, this only works if you have a BJL'd Jaguar, which everyone but me and a few other crazies thinks is heresy these days 🙂

 

Not a huge deal, but gave me quite a scare initially when I went to build some of those unpopulated fancy black PCBs from eBay after only recycling scrap cartridges from B&C in prior builds, which already had EEPROMs and capacitors on them, and wasn't getting any data saved!

Edited by cubanismo
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On 7/31/2020 at 4:43 AM, cubanismo said:

Not a huge deal, but gave me quite a scare initially when I went to build some of those unpopulated fancy black PCBs from eBay after only recycling scrap cartridges from B&C in prior builds, which already had EEPROMs and capacitors on them, and wasn't getting any data saved!

Just as a heads up, I have about 100 new black PCBs that I'll sell in lots of 5 for $20 shipped within the U.S. if there is any interest (the boards listed on eBay are not mine):

bpcb.thumb.jpg.ed9cefb806f0565ead3459157ed1d73c.jpg

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