2,889 reputation
1019
bio website cheshireeng.com
location Monrovia, CA
age 50
visits member for 5 years, 2 months
seen Sep 10 at 21:05

Engineer, Magician, Jack of all Trades


Sep
8
comment Sudden doubts about DVD+R reliability
We've tried media from a variety of sources, and recently replaced the DVD writer. Reading is still hit and miss across our office, even when attempting to read back with the same drive that wrote the platter.
Sep
8
comment Sudden doubts about DVD+R reliability
A workable Plasticback would have to include redundancy and resiliency against being transported on a hot dashboard. And I'm not sure what safe for home or office technology could be used to read it out non-destructively. I like the chutzpah of paperback, but it is still a lot of paper per equivalent DVD platter.
Jul
23
comment Sudden doubts about DVD+R reliability
At least DVD is optical, so it is still playing in the same sandbox as paper, just at a much higher resolution. And there are the M-Disc folks, claiming media that is etched and having a 1000 year lifetime. (Take that claim with a saltshaker, but note that normal media is in the sub 10-year lifetime ballpark.) But my problem right now isn't longevity. It is getting files back at all.
Jul
23
comment Sudden doubts about DVD+R reliability
@ChrisInEdmonton The discs are stored in a normal office environment both before and after writing, and both onsite and offsite. The images were written with verification on, and the software believes the images are intact. We have not investigated PAR2 or the like. Our experience is that we either can read the file, in which case it is complete and correct, or the entire file is unreadable. I believe there is some amount of ECC at work at the block level producing that result.
Jul
23
comment Sudden doubts about DVD+R reliability
@DanielB the most recent test was a freshly written disc, not yet stored for years.
Jul
23
comment Sudden doubts about DVD+R reliability
@DanielRHicks PaperBack is clever. But the back of the envelope says that 1 mostly filled DVD platter is on the order of 15 reams of letter paper... not necessarily the most practical of solutions. ;-)
Jul
23
asked Sudden doubts about DVD+R reliability
Jul
15
awarded  Yearling
May
5
comment What is this thing on the cord of my IBM model F keyboard?
Before cutting any of the cable open, use an ohm-meter to check for continuity. Each pin on the connector will almost certainly connect to exactly one pin on the other end of the cable. I don't know if the ground strap is connected to any of the pins, but it will likely be connected to the shell of the round DIN connector that plugs in to the PC. You can probably find the official wiring diagram of this cable as well, it was made at a time when IBM published full schematics of everything.
Mar
8
awarded  Scholar
Mar
8
accepted Should I worry that registry key HKCR\Installer\Assemblies refers to a disk drive that doesn't exist?
Mar
7
awarded  Popular Question
Feb
26
comment What's the logic behind the “W” in Control+W to close a Tab in IE?
As a long time user of an emacs-clone (lugaru epsilon, since version 3 or so) on DOS then Windows, the sudden introduction of that shortcut is annoying. On a traditional emacs binding, Ctrl+W is bound to kill-region, which is the most common command I use to cut selected text to the clipboard. When typing in a another context (like this comment right here) typing Ctrl+W has a very different and rather more catastrophic effect. Switching among several editor key bindings on the same machine is always a pain, but this one is relatively new compared to my history with epsilon.
Jan
30
comment Why the heck does NTFS allow invisible executables?
@NathanOsman The good news is that Windows Defender is defending you even from code that probably cannot be run at all on a 64-bit platform. :-)
Jan
13
comment In modern webbrowsers is there any point in putting www infront of a url that uses it?
@DarrelHoffman I usually pronounce it woo-woo-woo and that is usually understood in context.
Jan
7
comment IP address that is the equivalent of /dev/null
+1 for "you probably don't actually want any of this..."
Jan
7
comment In modern webbrowsers is there any point in putting www infront of a url that uses it?
I've always been amused that the acronym "www" requires far more syllables to pronounce (at least in English) than the entire phrase it replaces. At least it is easy to type... :-)
Sep
7
comment Why does RAM have to be volatile?
According to wiki what you describe was called NOVRAM. I've never seen one in the wild. Popular devices in the 80s were serial EEPROMs with a few 100s of total bits based on a floating gate technology, using large geometry to get good lifecycle times. EEPROM evolved into FLASH devices, which bifurcate to NAND for capacity and NOR for speed and reliability.
Aug
30
comment Why does RAM have to be volatile?
NVRAM is not the same as battery backed SRAM. NVRAM has a capacitor per bit that can be sufficiently insulated that any charge does not leak away, but can also be sensed, and programmed. The bit cell structure is fairly large, and in some technologies involved more exotic fab steps, so NVRAM is a low density high cost technology. But it also has very long storage lifetime. CMOS SRAM draws very little power when idle, and so backing it up with a battery is cost effective. The once common PC "CMOS" device is one example.
Jul
31
comment How can I remove a file or directory called “\”?
I always liked the file named * myself...