anyone interested in instant-on technology?

**brownpage** · 12-19-2003, 07:15 PM

Hi, guys. I have been building my carputer for a while, haven't finished yet.
I have an idea here.
I know many guys use shutdown controller to give their carputers enough time to shut down. However, I feel that's not neat enough. As when I drive my car somewhere, I may quite ofen ignite and shut down my car, so each time I ignite my car, my carputer has to restart. That will be a pain. If instead, I connect the carputer directly to the battery and let it run even I have parked my car, the car battery may dies out.

So I am thinking if there is a way to solve these two cases, that is, I can shut down my computer in no time and when I power it again, it starts in exactly the same state before shutdown! This sound a crazy idea, however, if you really think about it, it's not that crazy. Most of our electronic devices can start up instantly, only computers need a couple of minutes to start up. So I did some research on google, and I found some articles about this "instant-on pc" idea. But I haven't really found a practical way to accomplish this.

I think it's doable, like, the biggest problem for instant-on pc is that the sdram memory will lose its data in a power failure. However, we can use some method like the one used in hibernation to solve this. And, I found another possibility to solve this problem. If we can replace the normal sdram memory by some non-volantile memory, such as flash memories, we may be able to keep data in the memory even after power off. Also I have found something fit for this idea, it's called SyncFlash memory from Micron, and it is compatible with DRAM standard, but use the technology of flash memory. I don't know if the current processors support SyncFlash memories, but that's a possibility.

Is there anyone who is interested in these ideas? I hope to know your opinons, to make me not feel alone.

**henkbliek** · 12-19-2003, 08:42 PM

The problem is that flash memories have a limited number of write cycle. Depending on brand and technology, you can usually write a single flash cell between about 1000 and 100000 times. In a PC-memory configuration, this means that your memory will die in a fraction of a second.

What you could do, and that is what a typical embedded device has, is to program the memory footprint of the executable code in the flash. That way it will run instantly. The memory organisation of the PC is not meant for this kind of use however, so you have to program everything yourself, including the OS (or perhaps you could use some RTOS for i386).

**Naamanf** · 12-19-2003, 09:29 PM

Ummm...have you tried standby? My computer starts up and is playing music from where it left off in about 5-7 seconds. It actually turns on faster than the monitor.

**namshik** · 12-19-2003, 09:41 PM

well pda's are "instant on" ... if there's some way to get an ext. display connected to that

**eugenen** · 12-19-2003, 10:05 PM

PDA's basicall use the same technology as a laptop, suspend. They typically have less ram and lower power ram as well so they can set in suspend for a long time. Most modern motherboards support suspend and hibernate. So you could suspend which will keep the ram live and use a bit of current or hibernate which dumps the current system state to a file on the hard disk. Or setup something like Xp embedded or Linux for a simple and fast boot up system. You could always add in a second battery to keep your system in suspend without draining the start battery.

**CptnDipshit** · 12-19-2003, 11:50 PM

Would there be a way to create a ROM drive. Burn a small OS (or part of one) onto an EPROM (or EEPROM) and leave swapfiles and mabey a few drivers on the HD to cut boot time down to a couple of seconds? An IDE chip and supporting components and an (E)EPROM on a small board.

**shakes** · 12-20-2003, 12:00 AM

Originally Posted by Naamanf

Ummm...have you tried standby? My computer starts up and is playing music from where it left off in about 5-7 seconds. It actually turns on faster than the monitor.

do you mean standby or hibernate? i was doing some bench testing with my unit and when i put the system in standby it would still pull 1.64a (and didn't turn off the system fan) ... however hibernate showed a leakage of only .16a (compared to the .15a when system is completely off)

**Misanthro** · 12-20-2003, 12:30 AM

Originally Posted by shakes

do you mean standby or hibernate? i was doing some bench testing with my unit and when i put the system in standby it would still pull 1.64a (and didn't turn off the system fan) ... however hibernate showed a leakage of only .16a (compared to the .15a when system is completely off)

Hibernate does turn the computer completely off. RAM is stored on the hard drive, and the computer is shut off, so that's odd. How long do you guys think a standard car battery could take a 1.6 amp drain and still have enough power to start the car? Standby seems like an interesting option, I thought it drew much more power than that.

**shakes** · 12-20-2003, 12:40 AM

Originally Posted by Misanthro

Hibernate does turn the computer completely off. RAM is stored on the hard drive, and the computer is shut off, so that's odd. How long do you guys think a standard car battery could take a 1.6 amp drain and still have enough power to start the car? Standby seems like an interesting option, I thought it drew much more power than that.

Hibernate only shows .16a (not 1.6)

Standby pulls 1.6a ...

And like I said, my meter reads a leakage of .15a with the system completely off ... so I don't know if my meter is maybe lying ... or if the meter itself is causing that draw. (it is a cheapy)

**Misanthro** · 12-20-2003, 12:45 AM

Originally Posted by shakes

Hibernate only shows .16a (not 1.6)

Standby pulls 1.6a ...

And like I said, my meter reads a leakage of .15a with the system completely off ... so I don't know if my meter is maybe lying ... or if the meter itself is causing that draw. (it is a cheapy)

I must have worded that wrong. I meant how long do you think the battery would last on standby (with a 1.6 amp drain)?