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Cheap cartridges for developers and gamers


Zerosquare

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You may have heard about SCPCD's 4-way cart programmer - it's a device intended for devs/publishers to allow them to rapidly produce Jaguar games on flash cartridges (for the moment, this means Jagtopus).

 

I made a video of the programmer in action, check it out here.

 

Hi looking good, any date when final price of the flashcards and programmer wil be released ?

 

The programmer is an internal only tool, nobody would want to buy one if they had to pay what it cost for parts and labour :-)

 

As for end user carts to be BJL flashed (or whatever) - that's something people will have to really demand in numbers and convince those guys that there is sufficient demand to make it happen. Support, testing, logistics, finances... it's all a lot of hassle if only a handful of people would use them and a few more just wanted them to stick in a box with everything else.

 

Skunkboard is still the way to go for devving stuff - faster, simpler, rock solid. If people have a game they want to put out, maybe they should talk to SCPCD, Zero, RGC or RGCD.

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  • 1 year later...
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A few questions:

 

1. What is the disadvantage of only have a 16-bit bus access oppose to the standard 32-bit real cartridges use? Will it be slower at loading/accessing?

2. I didn't see an answer posted in regards to using sizes above 4MB. Would this require some sort of multi-banking or is 6MB+ actually possible rather easily?

 

 

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A few questions:

 

1. What is the disadvantage of only have a 16-bit bus access oppose to the standard 32-bit real cartridges use? Will it be slower at loading/accessing?

Standard jaguar cartridge is 32-bit in 10 clock cycles speed.

New generation cartridge with flash memory in 16-bit works in 5 clock cycles.

So we can say that the throughput is almost the same.

2. I didn't see an answer posted in regards to using sizes above 4MB. Would this require some sort of multi-banking or is 6MB+ actually possible rather easily?

The Jaguar ROM address space is limited to a direct 6MB, to use more memory, you need external hardware to do software bankswitching with, for example, logical device, PAL, GAL or CPLD.

 

 

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Thanks for the response.

 

Reading in the FAQs, I know the Jaguar could access at very least (externally) 2MB additional RAM, though one FAQ I came across said it could access up to 8MB (though I don't ever recall that being the case the whole time I've been into the Jaguar). Everyone is going out of their way for cartridge solutions but no one has (that I"m aware of) attempted to integrate the idea of adding more on-board RAM to be accessed via the cartridge (whether it be 2MB or 8MB, permitting that is even possible). Are there no readily available chips able to be used to do this? I'm guessing the cutdown to 16-bit access from 32-bit could pose a problem but isn't there a way aound that as well?

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The maximum amount of memory that can be mapped in the cartridge space is not 8 MB, but only 6 MB, because the upper 2 MB are reserved for things like the boot ROM, GPU/DSP RAM and hardware registers.

 

You could have on-cart RAM, but:

- if it's SRAM, suitable chips are probably expensive

- if it's DRAM, you'd need a FPGA or memory controller to manage it

- the performance will be limited because of the cartridge timings (at best 5 clock cycles per R/W access).

- the performance will be limited because of the cartridge bus width (at best 32 bits, but that would require several SRAM chips, or a FPGA with lots of pins, plus voltage translators)

 

Basically it's doable but not cheap, and it would be significantly slower than internal RAM.

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  • 7 months later...

Hi Matthias,

 

For games that have been released using Jagtopus boards (Another World, Elansar...), I haven't been involved in the financial aspects - I gave the manufacturing company contact info to the developers, so that they could order directly. As a consequence I don't know the current prices. If you have a project, let me know so that I can get you in touch with the right persons.

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