11/24/2023 0 Comments Chrome os raspberry pi 3> unfortunately, their current design seems to have a fatal flaw that renders it useless for its intended purpose, but one that's easily fixed It would make more sense to use either an ultra-low-power cpu, getting orders of magnitude more battery life (and probably reducing the weight and charge time of the battery), or a screen that takes advantage of the orders of magnitude more power available, with features such as backlighting, grayscale (the memory lcd is really only black and white with no shades of gray), or even color My comment on this three months ago got upvoted to the top of the thread, īasically, i said the ultra-low-power screen is wasted by using a cpu that uses ten thousand times as much power I very much agree about the clamshell that would also make it possible to include a keyboard big enough to touch-type on If not, i might have to lean harder on making the jit compiler smart I think, and i might be wrong about this, that this will be sufficient to run things like libpng and pcc at useful speeds My current plan is for my nascent jit compiler to implement paged virtual memory using bytecodes for paged-load-byte, paged-load-halfword, paged-load-word, paged-load-multiple, paged-store-byte, paged-store-halfword, paged-store-word, and paged-store-multiple, so that i can compile existing c to its bytecode instruction set these will be implemented by calls to millicode subroutinesĬ call and return, argument passing, and accesses to local variables whose addresses are never taken, can be provided by mechanisms that don't involve accessing a paged virtual memory space So, a drawback of the apollo3 (and actually every cpu i've found with a decent deep-sleep state) over an actual vax is that it doesn't have virtual memory or much in the way of memory protection Which reminds me, i'm late for a pairing session on a jit compiler targeting the ambiq apollo3 ultra-low-power 48 megahertz cortex-m4f ![]() So you can get a vax in your pocket that runs off a coin cell for six months ![]() ambiq's microcontrollers are two orders of magnitude lower, like 30 picojoules per instruction, so 100 μW should give you 3 mipsĤ00×240 is half the screen resolution of the original macintosh, and the same as the vt100, though with a different aspect ratio microcontrollers are typically an order of magnitude lower energy per instruction. a sleeping esp32 is supposedly around 10μW, and at full speed it's about 200 32-bit mips at 1 watt. ![]() If you pair that with a cpu that's using some similar amount of power, probably due to being in a low-power deep-sleep mode 99+% of the time, you can get a month or two of interactive computing out of a coin cell. I think i was the naysayer you're talking about ( ) and i have one slight correctionįor applications where its lack of backlight and grayscale mean you get a significantly longer battery life, or smaller battery, or no battery at allīeing able to maintain the display on 50μW means you can run it off a cr2032 coin cell for 17 months
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |