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Ksarul

2048K Cartridge

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Those of you who were either at the Chicago Faire or watching as Hal was showing the door prize I contributed know that there is a new, humongous cartridge board out there. This one uses non-inverted images (the same type used on the Red 512K and also on the ÜberGROM ROM side). Any ROM-only image set up for the Red boards will run on this board as well (I have test boards with all eight of those images set up on them). The board doesn't end there though--it works with images of several sizes: 128K, 256K, 512K, 1024K, and 2048K. The chips are not the same types used in earlier boards. These boards require chips capable of switching between 8 and 16 bit operation (the board uses them in 8-bit mode). I've tested the boards out with 512K 27C400 chips and with 2048K 27C160 chips. All but one of the 27C160s I got wouldn't switch to 8-bit mode as described in their data sheet (they work perfectly as 16-bit chips though). I've ordered some Maxim Flash chips that operate in the same 8/16 bit mode to see if those are more amenable to operation with the board--and I have ordered some one meg chips to test with as well.

 

What makes these boards seriously different (other than the size of the file it can use) is the type of EPROMs used. Up to 1024K they are 40-pin devices (which is about the max that most of the programers in use within the community can use with their EPROM burners right now), and the 2048K chips are in a 42-pin PDIP package. I have a programmer capable of doing all of these, so thee is at least one source of them from within the community, although if more show up, that would be good too.

 

They are not for sale yet--and won't be until I finish testing them with larger ROM images, but that shouldn't take too long once I get the chips in (soon, but probably not before the end of the month). The only current use-case is a compilation cartridge containing the first four of the Gazoo Game Cartridges. Note that these cartridges do not require switches to accomplish their magic--everything is already included in the hardware in the form of a 74LS377 for bank-switching. With that, we have reached the end of what is possible with off-the-shelf components. Anything larger would require a GAL with more I/O pins than the '377 has. EPROMs larger than 2048K also pretty much abandoned the PDIP format for TSOP and other surface-mount form factors, which I try to avoid due to the desire of most TI users to be able to populate their own boards.

 

I'll provide more information as it becomes available. . .so stay tuned. :)

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I am flabbergasted. After all the years of wanting a 128-in-1 cartridge like our other orphaned cousins, we have completely surpassed expectations. Not to mention with 2MB of space we could really have one helluva RPG :)

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Wow! Amazing! It's a cart space arms race!

 

Yeah, ya gotta love it! My imagined 'dream cart' is still quite a ways around the corner, if ever though.

 

Someday I'd like to own a cartridge with the following features:

 

A) XB 2.7

B) Editor Assembler / Word processor (80 Column version)

C) Multiplan

 

And of course with a ton of extra utilities like:

 

DM2K, DU2K, DSK2PC, HDX DSR LOADER, ARCHIVER, etc.

 

But lest you all think I truly lack imagination, it would also have a four bank Super Cart on board as well as reset switch. :)

Now, since you all know I'm always wanting more, we might as well add an SD card slot as well for things I'd like to use "at the moment", or when newer version of software are released.

 

Good luck building that one! :lol:

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Actually, you could probably do nearly all of that on an UberGROM board, Ohm.The XB 2.7 cart already has the TI Writer and E/A on it, along with some of the other utilities you mentioned, and Tursi has already noted that he's been working on code to allow you to connect an SD card to it (once you get a way set up between them to feed the necessary 3.3 volts to it). No way it will add Super Cart functionality though. . .

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Actually, you could probably do nearly all of that on an UberGROM board, Ohm.The XB 2.7 cart already has the TI Writer and E/A on it, along with some of the other utilities you mentioned, and Tursi has already noted that he's been working on code to allow you to connect an SD card to it (once you get a way set up between them to feed the necessary 3.3 volts to it). No way it will add Super Cart functionality though. . .

 

Yeah, there is always that one thing that eludes me, in this case the Super Cart aspect. Honestly though, if someone was eventually able to get 4A/DOS onto a multi-cart I'd be ecstatic. It would still require CHARA1 & AUTO-BAT to be on DSK1 though, but that's no big deal.

 

Yeah, the XB 2.7s Cartridge is the bomb, I love mine, but that TI-Writer is only 40 columns, so I'm using the 80-Column version of BA-Write off of disk instead.

 

I guess what I really want is an Uber Cart with stuff customized for use with the F18A (80 columns), and HDX board with room store future software that will eventually come out to support new hardware. I have an idea for a new device... ;)

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this sounds really "fantastic". Can this board also be used for GROM like the UberGrom board?

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With that, we have reached the end of what is possible with off-the-shelf components. Anything larger would require a GAL with more I/O pins than the '377 has.

 

Two '377s. ;)

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True--but then it also becomes a real estate issue. I can get a 26V12 GAL in there if I use a PLCC chip and still have room for the EPROM on the other end. That could conceivably get me four more latches--less if I want to force startup states and allow for inverted/non inverted output selection. Even then, with just 10 latches, you'd have this monstrosity that could hold 8192K. I'm not sure I could build a use case for an 8 Meg TI cartridge. . .the menus for the 2 Meg cartridge are already 8 screens long. . .

Edited by Ksarul

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True--but then it also becomes a real estate issue. I can get a 26V12 GAL in there if I use a PLCC chip and still have room for the EPROM on the other end. That could conceivably get me four more latches--less if I want to force startup states and allow for inverted/non inverted output selection. Even then, with just 10 latches, you'd have this monstrosity that could hold 8192K. I'm not sure I could build a use case for an 8 Meg TI cartridge. . .the menus for the 2 Meg cartridge are already 8 screens long. . .

 

... and what fun it was putting 126 menu entries in alphabetical order, and realizing it wasn't quite right, and realizing it wasn't quite right, and realizing it wasn't quite right, and realizing it wasn't quite right...

 

;)

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... and what fun it was putting 126 menu entries in alphabetical order, and realizing it wasn't quite right, and realizing it wasn't quite right, and realizing it wasn't quite right, and realizing it wasn't quite right...

 

;)

 

Not to mention having to keep a spreadsheet of what is in all the banks.

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Not to mention having to keep a spreadsheet of what is in all the banks.

 

Well, I cheated a little. ;)

 

I just joined the 4 images together. Then for the bank switching on the 2nd bank I added >80 to all the existing values, for the 3rd bank added >100, and for the 4th bank added >180. I was able to combine the menu source from all four carts and just delete or edit parts of it for the most part, the only real work was creating the new menu screens.

 

Gazoo

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I am flabbergasted. After all the years of wanting a 128-in-1 cartridge like our other orphaned cousins, we have completely surpassed expectations. Not to mention with 2MB of space we could really have one helluva RPG :)

 

I would love to see an RPG come out of this much space!!!!!

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True--but then it also becomes a real estate issue. I can get a 26V12 GAL in there if I use a PLCC chip and still have room for the EPROM on the other end. That could conceivably get me four more latches--less if I want to force startup states and allow for inverted/non inverted output selection. Even then, with just 10 latches, you'd have this monstrosity that could hold 8192K. I'm not sure I could build a use case for an 8 Meg TI cartridge. . .the menus for the 2 Meg cartridge are already 8 screens long. . .

 

Just musing for the sake of musing now, but what if you went double-sided? A quick test suggests there is enough room under the PCB to still fit a standard case. If you trimmed the through pins very close to the board, you could mount the banking chips under the EPROM ;)

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Useful idea, Tursi--and they would definitely fit that way. I'll have to mull that one over and see what comes out of it. :) I've been working on some layout projects for Rasmus (done) and Atrax (in progress) since I got back from the Faire. I also updated my 2048K boards to rearrange the lines coming into the jumpers (in the original layout they were present but didn't move the correct line to ground when set in non-default position). Everything worked--it just didn't do the additional thing I wanted it to do.

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I know--but you got my interest piqued with it, so now about one sixth of it is in a new layout. . .it is definitely interesting and a nice size using easily sourced chips. . .once the user burns a set of the PALs for it (or gets a set with the bare board).

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So the new board can take one large 2048K image? Could you make a giant multicart image out of all those game compilations that have been released for the 512K cart then?

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Gazoo made me a compilation image of the first four game carts, Tempest--but I have to get some of the chips to put the image into for testing. The first batch of chips I received would only work in 16-bit mode (contrary to the data sheet), with the exception of one chip. . .

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Just in time for Christmas, I now have a sufficient stock of good chips to announce the general availability of the 2048K cartridge board. As it stands now, there is just one image built for the board, containing the entire contents of the first four 512K Games cartridges--and all games except Attack of the Creepers work properly. Note that some require you to press a key on the keyboard to start, some require the presence of joysticks to work, and some require the speech synthesizer. My boys have pretty much tested this cartridge to oblivion now, so the image (and the hardware) is solid. I may be the only person around with a programmer that will do the 27C160 chips it uses, so this one will only be sold as a complete cartridge for now with the 2048K Games 1 image on it, for $35 each, shipped to a US address. Cartridges will have the same style professional labels as the ones we've been using for the 512K carts.

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I have been working on moving threads, too. So far I have moved about 100 or so over, and the PCB threads are ones in my sights. While we are working on splitting up the threads, I welcome any recommendations via PM.

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