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Messages - Keoni29
Pages: 1 ... 31 32 [33] 34 35 ... 168
481
« on: April 08, 2014, 09:14:39 am »
If I did not care for the esthetics of my projects I would have started writing android apps a long time ago.
482
« on: April 07, 2014, 03:58:08 pm »
Is this project still being worked on?
483
« on: April 07, 2014, 09:10:18 am »
Holy necropost batman. That must be a new record!
484
« on: April 07, 2014, 08:51:23 am »
That is right. Not only did we choose to design the hardware ourselves, but we also wanted to write the operating system for it from scratch. There are not a lot of people who use this microcontroller in the way we do.
485
« on: April 07, 2014, 05:40:59 am »
It is tough to find all of this information condensed in one webpage/datasheet, because the technology is obsolete. I bet there are some great websites out there, but they have been buried below thousands of floppy drive music tutorials.
486
« on: April 06, 2014, 03:02:59 pm »
I am still figuring out how this works, so this information is not 100% correct!
Old hard drives use the same magnetization patterns as floppy disks. It is called MFM (Modified Frequency Modulation)
I just read a datasheet of a diskette drive. Data is stored as changes in the magnetization layer. On a transition a short low pulse can be detected at the DataRead pin of the drive. The time in between those pulses represents a bit pattern.
2us pulse = a > next up: a
3us pulse = ab > next up: b
4us pulse = ab > next up: a
Example of a pattern starting with logic 1.
Pulse length: 2 3 3 4 ...
Bit pattern: 1 10 01 10 1...
The byte on the end
I do not know how the start of a sector is marked yet though.
487
« on: April 06, 2014, 10:50:39 am »
I have been experimenting with floppydrives today. I found out that you can pretty much define your floppy's data density yourself if you write data slow enough. An IBM formatted double density floppy's shortest pulse length is 4microseconds. The eZ8 runs at 20MHz, so that is a minimum of 80 clocks per signal change. In order to simplify the operating system I will use a second eZ8 to control the floppy drive.
488
« on: April 05, 2014, 12:53:21 pm »
Nope not really. The parts list was based on the old portable design. I kind of deviated from that idea. I might go back to it though since the operating system allows the use of multiple output devices. I only need to add driver code for an lcd screen.
489
« on: April 05, 2014, 12:47:45 pm »
For the prototype it is well over $30. The gameduino alone cost me $40+10shipping+$20tax+customs fees. It was pretty expensive.
490
« on: April 05, 2014, 10:59:21 am »
Perhaps it is some kind of debug interface. There should be interesting stuff on the uart.
491
« on: April 05, 2014, 06:18:39 am »
@Keoni: Nice!
@DJ: Never played Double Dragon V. Too bad it only 1vs1. That's like the alternate mode on Double Dragon I. 
Picked up ICO & Shadow of the Colossus HD Collection for PS3 for $10 at Wal-mart.
Wow nice. ICO costs about 26-40 euro here
492
« on: April 05, 2014, 06:09:44 am »
I am waiting for the flash rom to arrive. Then I can continue working on the filesystem.
493
« on: April 05, 2014, 06:05:08 am »
You mean the pins on the board marked with rx and tx?
494
« on: April 04, 2014, 10:12:23 am »
495
« on: April 04, 2014, 03:17:51 am »
Oops did not change the link. Just thke link text
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