This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
Messages - wchill
16
« on: August 23, 2010, 05:16:41 am »
I'm thinking something on the lines of what Apple does, except with more information than just a pic 
For what, exactly?
17
« on: August 23, 2010, 12:45:47 am »
Dust? Dust could screw with the fans and make your GPU/CPU run hotte.r
18
« on: August 22, 2010, 11:55:11 pm »
I didn't really read that document, but it appears to be NOR flash.
The problem with NOR flash is the slow write speeds. Apparently that company's NOR flash implements a buffer or something (section 8.4) to speed up writes, however I'm still unsure how slow/fast the NOR will be.
But the exciting thing about it is being able to XIP (execute in place) meaning you can keep your programs in NOR flash and run them there!
19
« on: August 22, 2010, 09:42:31 pm »
Regarding other parts. I found these USB mini A to mini B cables for link cables (assuming we use miniUSB OTG) http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=WM17494-NDAssuming we buy 100 at a time, that's around ~$2.18 per cable. Regular miniUSB cables are slightly cheaper at $1.90/unit for 100 ( http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=Q362-ND). However, eBay auctions have these cables in auctions for considerably less than a dollar each. discmakers.com manufactures 100 CDs for $162 and 100 DVDs for $202 shipped + with paper sleeves. So we're looking at ~$2 per disc. For packaging, we can use printed boxes. Makes it look professional but doesn't cause the user to go #$%^@&$! when trying to open it. Think smartphone boxes, with their component trays and everything. Manuals are quite expensive, unfortunately. A black tape bound 50 double-sided page manual is ~$7 each at mimeo.com. An option here is to make a Quick Start kind of sheet and put the manual on the printed disc.
20
« on: August 22, 2010, 08:39:53 pm »
SDHC is for cards >4GB.
There are some 4GB non-SDHC cards, but they don't conform to specifications.
Anyway, I doubt OTeZ80 will need anything even close to 1GB.
Now, how about this:
If OTeZ80 will use a USB OTG port, why not just code in support for external storage into the OS and forget the SD slot?
If you don't want/need one, don't use one. If you want/need one, use one via the USB OTG port.
You'll need one of those cables like what usb8x uses, but it seems a fair compromise.
The idea is that we can port something like usb8x and make it as part of the OS, then create a driver for it. Only cost there is developmental time.
21
« on: August 22, 2010, 04:42:38 am »
If we use a read-only bootloader, then I think the prototype OTARM calculators should use EEPROM or some kind of rewritable memory. It would suck to have to create a new prototype for each revision of software.
I believe the point of making an OTcalc was to provide a competitive alternative to TI's calculators and to allow the user to tinker around (unlike the Nspire). Something like superuser privileges being disabled by default would work, and you would need to "root" the calculator in order to use root access (similar to Android, but less cumbersome).
22
« on: August 22, 2010, 03:45:07 am »
If you're going to go OTG, will it be a miniUSB or microUSB port?
The miniUSB port is officially deprecated, but the microUSB cables are considerably more expensive (and I have yet to find a microA to A cable at a reasonable price).
23
« on: August 19, 2010, 05:41:10 am »
OTARM will also require a fail-safe bootloader for in case a user manages to break their calc, which is entirely possible with root privileges.
The main filesystem should be FAT, FAT32, or ext2, I believe. Assuming that we're going to use flash memory, ext3/ext4 will wear out the flash much faster because of the journaling. SD cards need to use FAT/FAT32 simply because of Windows.
24
« on: August 16, 2010, 05:28:22 pm »
If you want to be able to read/write to the OTARM filesystem, FAT32 is probably the best choice, unless you use some kind of client software to manage file transfer (not recommended).
Depending on the speed of the ARM processor and some other hardware choices, we can also use a custom build of Android (like what they've done for BeagleBoard). This would do two things:
1) Allow for the familiar Android interface with the ability to customize
2) Allow us to hopefully make apps compatible with Android, allowing us to sell it for project funding + compatibility with other Android apps
I probably missed something there, but who knows.
25
« on: August 16, 2010, 05:18:42 pm »
If OTARM is going to be faster than Nspire, we can go with one of the lower-end 375MHz A8s. More than sufficient to run a slimmer build of Linux.
26
« on: August 16, 2010, 05:07:01 pm »
My school's robotics shop computers were all infected with viruses because some idiot brought in an infected flash drive.
So what I did was open up Security Center, use Paint to modify the antivirus part of it so that it said "This computer has been infected with (some number of) viruses!", and screenshot/desktop background.
Someone else happened to do the background thing on another computer, except he also renamed all the icons to inappropriate things (Turbo C++ became Turbo Vibrator, for example)
27
« on: April 04, 2010, 09:41:59 pm »
That could work. But unfortunately this form of OTP on a calculator is a memory hog.
The memory usage works out to basically ~57 bytes per character while it's processing everything.
Using compression on the lists increases processing time and I don't want to make it a lot slower than it is right now.
Short password lists (or math formulas?) could work, as long as you can protect the program, encrypted data and key themselves.
If only there was some faster way to use the sub( command, eh?
28
« on: April 02, 2010, 01:51:37 am »
: " →Str1
: For(I,1,C)
: ∟ENC(I
: While Ans>length(Str0
: Ans-length(Str0
: End
: Str1+sub(Str0,Ans,1→Str1
: Output(3,1,iPart(100I/C
: End
: sub(Str1,2,length(Str1)-1→Str1
29
« on: April 02, 2010, 12:54:24 am »
The conversion code goes something like this:
-Character set stored to Str0.
-Initialize Str1.
-For( loop through list elements.
-Perform modular arithmetic on list element.
-Place character in string using Str1+ sub(Str0, Ans, 1 -> Str1
-End For( loop.
-sub(Str1, 2, length(Str1)-1 -> Str1 (removes initial space stored to Str1)
30
« on: April 01, 2010, 11:56:46 pm »
I actually believed the story this morning. 
|
Show Posts
