180 reputation
6
bio website
location New York City
age
visits member for 3 years, 1 month
seen May 20 at 15:49

I am an embedded programmer currently available for contract work in NY City or remotely.

My specialties include

  • Android, especially troubleshooting obscure issues and the underlying Linux
  • Embedded Linux
  • Smaller microcontrollers
  • FPGA/Verilog design
  • Debugging and interfacing to undocumented systems

May
6
comment why are RAM chips independent of whether my system is a 32bit system or 64 bit system?
In fact, it is routine for memory interfaces to be wider than the processor word (for filling caches, or for using parallelism to deal with slow memory technologies), or also for them to be narrower (to simplify circuitry). Also, today 32 vs 64 bit is as likely to refer to the mode of operation utilized by an operating system as to the actual processor word width.
May
1
comment Laptop crashes at 60 c
If indeed it is overheating related, it's possible the part overheating is some distance from, and quite hotter than, the temperature sensor you are looking at. Or the sensor you are watching could be bad, or a different faulty one could be triggering a protective shutdown that looks like a crash. Or perhaps there are incompatible reporting mechanisms.
Jan
28
comment Where is the BIOS stored?
Indeed, phototransistor effects leading to a temporary crash are a much more plausible explanation than eeprom cell erasure. Years ago, decapping DRAM chips to make crude cameras was briefly in vogue; I tried it, but without putting real effort into optics (just trying to light/shadow half the array) all I was getting was phototransistor action of the output circuitry.
Jan
27
comment Where is the BIOS stored?
Back in the day, most PC repair/build shops had an EPROM burner - likely not every copy of a bios that went into an XT clone was licensed. These were standard parts, containing a program performing highly standardized functionality - although not what we got, it was hinted copies of the IBM ROMs would work in the machine we purchased. EPROMs when purchased typically came blank, able to be programmed without erasure. You only needed the UV if you made a mistake and wanted to re-write one. Even then, you could turn 1's into 0's without erasure, a fact still exploited by some storage schemes.
Jan
27
comment Where is the BIOS stored?
You are confusing the bios program with it's settings data. The obvious distinction: remove the backup battery and the program still runs, but its settings are reverted to default. While the settings are battery backed, the program is stored in a "read mostly" memory technology which requires active measures to erase.
Jan
27
comment Where is the BIOS stored?
What do you mean nobody has the equipment to reprogram an EEPROM? It was easily rigged up with a parallel port and I/O expander - something like an 8255. Regardless, consider the advantage to a manufacturer who discovers a tiny bug which needs to be fixed - UV meant paying overtime to fix existing units, not the delay and cost of sourcing replacements. UV light is not required to Program EPROMs, only to erase them. Stories of erasing a UV eeprom with a camera flash seem rather preposterous - you'd be damaging your eyes with a flash that could do that in any small number of repetitions.
Jan
27
comment Unmounting Detachable devices (eSATA,USB storage) in Linux
lsof simple trolls through the per-process proc/##/fd directories - you almost certainly have a /proc filesystem these days. So you can either port lsof or easily duplicate it's functionality. Chances are it's already available as an option in busybox which you merely have not enabled in your build.
Dec
10
comment How can I increase the maximum number of USB devices that can be connected at one time in Windows 7?
From comments in the stackoverflow question, it appears the actual problem is running out of virtual COM port numbers to assign to the user's USB-serial devices.
Dec
10
comment Does HDD need to be screwed in?
I've seen adhesive mounted drives (but be careful of cooling), and I've seen manufacturers strongly caution against forcing screws in where that could distort the casting.
Oct
24
comment How can I delete a user which is logged in and have a uid=0
You do not want to delete that account. Also this is off topic here.
Oct
14
comment Bad effects of coiling up HDMI cable?
Whoever downvoted this, please note that the reference is to common mode interference in which the current on both the signal and the shield is in the same direction, in contrast to the differential mode of the intended signal where the signal and shield currents are in opposite directions.
Oct
14
awarded  Supporter
Aug
27
comment Can I use a CNC 3020 router on Linux with a USB to parallel cable to mill PCBs?
Actually it's more fundamental than that - regardless of software , USB is not suited to carrying raw step pulses, but only higher level data from which they could be generated.
Jun
7
comment I can't change permissions in /media folder
Actually, you don't need to restart - just log that user out and back in again, possibly even on a per-shell (window) basis.
May
22
comment In Linux Driver, how to disable a specific USB Device
This should be sent back to stack overflow, as it concerns low-level internal details of the USB driver (ie, kernel programming), not configuration.
May
21
comment In Linux Driver, how to disable a specific USB Device
I seem to recall that there actually is a standard way to tell a hub to power down a port, but most are built without the necessary high side switches to actually make it work (even if the logic that would control them is there). If the firmware is really in a bad state, it's possible that no USB bus state transition that doesn't interrupt power will fix it (since the firmware has to make an effort to actually pay attention to the USB), though if it's a firmware undergoing development it might be worth checking if the MCU on which it is running has a watchdog timer which could be enabled.
Mar
15
comment What is the advantage of using 'tar' today?
Actually, most stock Android firmwares have an unzip and use renamed and optimized zip files as their application delivery format, and they may have a gzip, but they do not have a tar. Alternate installations often have a more complete unix toolset.
Jan
21
comment How to get Mac OS X 10.8 (Mountain Lion) to see USB modem device (Arduino)?
Wouldn't it make sense to examine the board and look for an FTDI part, vs another Atmel part?
Jan
15
comment How can I combine the output of 2 laptops through 1 set of speakers?
@Kortuk Move the question back to the site where such an answer would belong, and we can make some progress.
Jan
15
comment How can I combine the output of 2 laptops through 1 set of speakers?
@Kortuk - factually untrue! The poster explicitly mentions willingness to solder something together, hence there's an openness to the design of a proper mixer circuit. Dumping the question to superuser where it is limited to moderately unsuitable off-the-shelf widgets does a real dis-service.