mos6507's Blog - Scalable board design

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Just a quick note about some changes in the current board design.

 

First off, the SRAM area has two footprints on them in order to accomodate two different kinds of SRAM chips. The SRAM chip is what is used to house the ROM code (or the cart RAM in the case of Supercharger, Ram+, etc...). So it can accomodate chips from 128K up to a whopping 512K. Before it was maxed out at 256K.

 

On the ARM front, during the hiatus, NXP released yet another ARM variation called the 2387. This has a full 64K of highest speed internal memory (plus other useful memory blocks), which could make the concept of loadable custom ARM modules truly viable, or storing much more data in fast queues at once.

 

The LPC2387 might as well have been called a LPC2369 for that matter. The difference is the SRAM size and the absence of the speed related Erratas. The LPC2387 is obviously based on the corrected database of a LPC2368 rev “B”.

 

http://www.lpc2000.com/apnotes/LPC2300.LPC2400_Q_A.htm

 

It shouldn't cost a lot more to max out the board, but everything does start to add up so I'm going to need some feedback before final decisions are made on which chips to ship with the production Chimera.

 

For the most part this stuff is irrelevant to end users who want to use Chimera as a multicart. It's more for developers who want the headroom to make a homebrew that are at the absolute bleeding edge. So we could create a low and high end model. I would just prefer to set a high bar so that end users could one day transition into being coders or Chimeras can circulate in the aftermarket and change hands from gamers to coders without introducing any artificial barriers.

 

 

 

http://www.atariage.com/forums/index.php?a...;showentry=4914