xrbrevin Posted July 29, 2018 Share Posted July 29, 2018 I am aware you can mod the XE super carts to take other EPROMs but can the same be done with the older brown carts? I have a missile command PCB with 2x socketed 24-pin chips and i wondered if there is a way to change its content. cheers! Quote Link to comment Share on other sites More sharing options...
1050 Posted July 30, 2018 Share Posted July 30, 2018 Not easy at all as Atari went way out of their way to corner the cartridge market with extra custom OTP so called maskable PROMs for the cartridges. So if you want to use the cartridge board as is you also have to have reverse polarity enable function chips and with moved pins from standard EPROM locations too. It's really easier to buy your own EPROM board from B&C for example. IIRC, some pink cart boards from Atari with a single chip were slightly less of a nightmare to work with, but these are a bit rare. So missile command is 8K and on two PROMS then you need two 4K eproms and to split the code. And some are done already because this just went past the easy part. End of the day your 4K EPROMS will have some dead bugs mounted to them with lifted legs on the EPROMS too. And this makes reusing the EPROMS difficult too. Yes there is a way to change the content but it's a very real nightmare and challenge to do so. Exactly what Atari wanted when they did it this way. Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted July 30, 2018 Author Share Posted July 30, 2018 Hi, Many thanks for the info. Looks like atari achieved what they set out to do - the task is to prohibitive... i'll do the xe cart mod instead. Cheers! Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted July 30, 2018 Share Posted July 30, 2018 Seems that for at least the Atari BASIC 8K cart, even though it's two 4K ROM's, a single 2364 (8KB) compatible e-prom would work in 1 slot. Example: BASIC PCB with Retro Innovations 2364 --> 2764-27512 adapter in one of the sockets ( http://www.go4retro.com/products/23xx-adapter/ ) http://atariage.com/forums/topic/187359-looky-what-i-uh-found/ 16K PCB's are probably much more difficult to re-purpose... 1 Quote Link to comment Share on other sites More sharing options...
lbaeza Posted July 30, 2018 Share Posted July 30, 2018 Hi xrbrevin Please let me know if this is of any help: https://www.insentricity.com/a.cl/200/A800-2764 Regards, Louis BQ 1 Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 30, 2018 Share Posted July 30, 2018 68764s and 68766s also work (if you can find one). 1 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 1, 2018 Author Share Posted August 1, 2018 hi, much appreciated, i'll have to give it a go! Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 24, 2018 Author Share Posted August 24, 2018 Hi xrbrevin Please let me know if this is of any help: https://www.insentricity.com/a.cl/200/A800-2764 Regards, Louis BQ it works first time! - i made my own SALT cart thanks again Quote Link to comment Share on other sites More sharing options...
lbaeza Posted August 25, 2018 Share Posted August 25, 2018 Cool xrbrevin! Can you post a picture of your modified cart?Kind regards, Louis BQ Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 25, 2018 Author Share Posted August 25, 2018 (edited) here it is: the 3x cut tracks are all on the reverse i used single core wires and soldered them right into the PCB through-holes i soldered the wires directly to chip pins 1, 2, 27, 28 which means i cannot 'hot-swap' EPROMs but it wouldnt be too hard to wire them up to the socket instead. i intend to keep this as a SALT cart so its fine for this purpose now i could do with making a 16k SuperSALT cart... the challenge continues! Edited August 25, 2018 by xrbrevin 3 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 25, 2018 Author Share Posted August 25, 2018 looks like the 27128 EPROM is also DIP28, the only pinout difference is pin 26 = A13. the other option is to consider 2x 2764s with the code split in two Quote Link to comment Share on other sites More sharing options...
+David_P Posted August 26, 2018 Share Posted August 26, 2018 Or go to OSH Park and order 27128 EPROM boards that fit in the old brown cart shells: https://oshpark.com/shared_projects/YreZRvio http://www.grandideastudio.com/pixels-past/ 1 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 26, 2018 Author Share Posted August 26, 2018 Or go to OSH Park and order 27128 EPROM boards that fit in the old brown cart shells: https://oshpark.com/shared_projects/YreZRvio http://www.grandideastudio.com/pixels-past/ hmmm, their schematic for the the 27128 version shows A13 connected to cart slot pin 1 - which is absent from the old brown cart PCB!... i think your link will be the way to go thanks! Quote Link to comment Share on other sites More sharing options...
1050 Posted August 26, 2018 Share Posted August 26, 2018 Pin 1 absent from the old brown cart board simply means that your particular selection for cart board to work on was NOT a 16K cart as issued. Another old brown cart board that was 16K would have that line... Take away tuesday on a sunday is that all old brown cart boards are not the same ting. If you'll look harder you might find one suitable for further studies. I bet it won't cost $30 either. B&C used to sell twin EPROM ready and fitting brown case boards for less than that, but they are doing revisions to their supply listing and zippo is what they got listed for sale right now. Quote Link to comment Share on other sites More sharing options...
+David_P Posted August 26, 2018 Share Posted August 26, 2018 The cost is $30 for 3 boards; alternatively, you can get 20 boards for $120. You may be able to get lower costs from other board makers, but I've had nothing but great results and experiences with OSH Park. 1 Quote Link to comment Share on other sites More sharing options...
1050 Posted August 27, 2018 Share Posted August 27, 2018 Now that's much more reasonable, didn't spot that first time thru there so my bad there. Thanks because they deserve the business when they play fair. Quote Link to comment Share on other sites More sharing options...
+David_P Posted August 28, 2018 Share Posted August 28, 2018 OSH Park's pricing is a bit confusing, and their website isn't always easy to figure out... but the handful of times I have ordered they've given fast shipment and a quality product... and purple boards, to boot. Specify quantity 20 and "Medium Run" and the price goes to $117.80. And Best shows cases for $4.95 in the addendum: Page 103 Atari 400/800/XL/XE Empty Game Cartridge with metal back. CB101080 $4.95.(http://www.best-electronics-ca.com/addendum.htm) Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted August 28, 2018 Share Posted August 28, 2018 I bet it won't cost $30 either. B&C used to sell twin EPROM ready and fitting brown case boards for less than that, but they are doing revisions to their supply listing and zippo is what they got listed for sale right now. Yeah... I put an order into Bruce last month, quoting a bunch of stuff from his price lists on the website.. He was able to accommodate my requests, but he indicated he was really overloaded and his website was way out of date, which is why removed all the items from his website. He still has lots of stuff, so I guess its e-mail only for now to ask what he has .. Anyway, here's the line items with prices I paid for EPROM PCB CARTs straight from my invoice: PRA062 PCB CART board 16K for EPROMs W/SOCK 2-2764s - $8.00 PRA065 PCB CART board 8K for EPROMs W/SOCK - $9.00 1 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted August 28, 2018 Share Posted August 28, 2018 xrbrevin, I just wanted to say thanks for posting your detailed pictures of the 8K PCB mods! I was thinking of doing this with a go4retro adapter board, but I'm pretty sure that would not fit inside the case. Your pictures will make it easy to do this without the adapter board, looking forward to trying this out. Quote Link to comment Share on other sites More sharing options...
BillC Posted August 28, 2018 Share Posted August 28, 2018 (edited) Yeah... I put an order into Bruce last month, quoting a bunch of stuff from his price lists on the website.. He was able to accommodate my requests, but he indicated he was really overloaded and his website was way out of date, which is why removed all the items from his website. He still has lots of stuff, so I guess its e-mail only for now to ask what he has .. Anyway, here's the line items with prices I paid for EPROM PCB CARTs straight from my invoice: PRA062 PCB CART board 16K for EPROMs W/SOCK 2-2764s - $8.00 PRA065 PCB CART board 8K for EPROMs W/SOCK - $9.00 The 16K EPROM boards for the brown cartridges can also be used as 8K boards, using a single 2764, by cutting a single trace on the solder side. I posted details on this modification in the post linked below: http://atariage.com/forums/topic/178027-memtop-issue-with-cartridge/page-1?do=findComment&comment=2223087 Edited August 28, 2018 by BillC 1 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 28, 2018 Author Share Posted August 28, 2018 (edited) xrbrevin, I just wanted to say thanks for posting your detailed pictures of the 8K PCB mods! I was thinking of doing this with a go4retro adapter board, but I'm pretty sure that would not fit inside the case. Your pictures will make it easy to do this without the adapter board, looking forward to trying this out. youre most welcome! here is an image showing which traces to cut, circled in yellow. im now attempting my first 3D printer design for cart cases using freecad. ive done most of 1 half but i cannot seem to cut the 2x notches out of the main body nor reduce the height by 2mm!.... if i get it done i'll upload it for all to use/modify Edited August 28, 2018 by xrbrevin 1 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 30, 2018 Author Share Posted August 30, 2018 Here is the finished SALT cart! 1 Quote Link to comment Share on other sites More sharing options...
+David_P Posted August 30, 2018 Share Posted August 30, 2018 Is it also available with a "NaCl" label? #ChemistryGeek 2 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted August 30, 2018 Author Share Posted August 30, 2018 i used images from this thread to make my own label: http://atariage.com/forums/topic/189247-8-bit-cartridge-label-project/page-2 Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted August 31, 2018 Share Posted August 31, 2018 Is it also available with a "NaCl" label? #ChemistryGeek How about I paint the label with a solution of NI3 and allow it to dry, and then you touch it? That would be fun. Quote Link to comment Share on other sites More sharing options...
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