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Post by gmoon on Mar 10, 2007 8:11:06 GMT -5
@ racob: Yeah, Digikey seems to be the one distributor that gets ALL the Atmel products...
@ andydtv: I assume the same, too. "Cherry picking" is also how they separate the military spec ICs. Test a percentage of each production batch to failure, grade the remaining chips on the results.
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Post by rrolison on Mar 10, 2007 9:28:27 GMT -5
I'm running mine using an Atmega32L running @ 3.3v.
It's worked flawless since I've put it together. Lots of loading. Lots of files loaded that were 180+ blocks. (nice long stretch) Maybe I'm just luckier than the people with the rare loading errors?
I have two Atmels in my joystick. The other is a keyboard controller. Every time the system is turned on or reset, the keyboard controller injects the load command that resets the MMC2IEC into the keyboard buffer. So, this drive is always reset before use....
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Post by gmoon on Mar 10, 2007 10:59:45 GMT -5
@ rrolison:
Where'd you get the nice MMC/SD socket? Most need to be mounted directly on a PCB (and require some traces to operate), but that one looks 'stand alone.'
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Post by rrolison on Mar 10, 2007 11:08:35 GMT -5
Digikey part# HR845CT-ND $4.67
They are surface mount type. Nice ones. Push in. Push in again to eject. It's a locking type. It also claims to be moron proof for the guy that just wants to yank it out. The push to eject is nice, because the card is about 90% buried in the DTV during use...
Anyhow, the shape of the legs is cool. I flipped it upside down and soldered fine wire to the legs easily. I wired up everything properly, even the card detect switch. Not knowing until afterwards that it's not supported in the software yet...
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Post by 1570 on Dec 23, 2007 13:36:03 GMT -5
Just FYI, there's been a lot of activity concerning the MMC2IEC in Forum64.de lately. Unseen wrote a new firmware that features better IEC compatibility and even some fastloader support (currently "Turbodisk" fastloader only). Many games now run using MMC2IEC - see [1] for a list. There's a new wiki page for the MMC2IEC: www.c64-wiki.com/index.php/MMC2IECSchematics, PCB layout, and firmware are available there as well as further information ( in english). I built a simple version of the device (one-sided PCB, DIL chip, DTV only). Will add information on that to the wiki page later. When soldering the ATMega32 directly, it might be possible to make it small enough to fit into a DTV - even without SMD parts. Shadowolf's MMC2IEC version (which is SMD-based) is barely larger than the SD slot. [1] www.forum64.de/wbb3/index.php?page=Thread&threadID=19522 - german but you'll spot the games
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Post by racob on Dec 24, 2007 12:23:30 GMT -5
Alas, as I lamented before, (maybe i can speak for some North American members) I can not speak nor understand the language...so even wishing to be member of Forum64.de would not do me any good.
I wish some friends here can pass on the goodies that can be shared like being able to download the games as mentioned. I really would like to try that new firmaware with "turbodisk"
Anyway, thanks for the info.
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Post by shadowolf on Dec 24, 2007 12:35:12 GMT -5
The WIKI is Englisch and from there you can get here: snowcat.de/mmc2iec/Where you find snowcat.de/mmc2iec/sd2iec-0.4.1-hex-m32lp.zipThis is the latest sd2iec firmware for MMC2IEC with the original design by LarsP. You'll need a crystal though to really use the fastloader-support since even calibrated the internal RC-oscillator is not accurate enough. Which is why I changed my hardware variant to include a crystal.
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Post by racob on Dec 24, 2007 13:09:02 GMT -5
Thank you Shadowolf for the quick response.
Merry Christmas to all
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Post by 1570 on Jan 2, 2008 22:06:39 GMT -5
I think the timing is pretty important in the IEC-bus routines. Some lines have to be pulled low in an exact timeframe. That's why Jan Derogee used a 20 MHz crystal in his 1541-III, although the used PIC has an internal 8 MHz RC-oscillator like in the ATmega's in MMC2IEC. While timing certainly is important, it's not microcontroller processing power that matters really - current microcontrollers are by far powerful enough with 4+ MIPS (compared to <<1 MIPS on C64 side). What matters is exact clock frequency: Some speeders do not synchronize for more than 10.000 C64 cycles. However, with speeders that synchronize on a per-byte basis (Jiffy...) this is not a problem really even if the clock isn't completely exact. BTW concerning oscillator calibration values, in theory you can run a small program on the C64 that toggles IEC lines every X cycles and use that reference signal for calibrating the IEC device. The C64 helper program and a bit of measuring code on MMC2IEC side is all that's needed for this. Of course this is not needed if you use a crystal though.
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Post by Unseen on Jan 13, 2008 6:20:10 GMT -5
Alas, as I lamented before, (maybe i can speak for some North American members) I can not speak nor understand the language...so even wishing to be member of Forum64.de would not do me any good. Well, that's the reason why the README, (almost) all the comments in the source code and even the check-in comments are in something that may actually pass for English. For some strange reason noone at Forum64.de has yet complained about that even though I know there are some people there who can't read it... You may want to check out version 0.5 in that case, 0.4.* had a few problems with LarsP-style hardware. Besides, it now supports JiffyDos (which is rather tolerant of slight timing errors, so it even works with a miscalibrated internal oscillator) and D64 images (read+write). =)
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Post by 1570 on May 24, 2008 4:09:01 GMT -5
Some news: The MMC2IEC hardware has been reworked and is now called SD2IEC. It features the ATmega644 microcontroller (more flash memory and RAM) and an improved IEC driving circuit. Its firmware version 0.7 supports Jiffy and the Final Cartridge 3 fastloader. Long filenames are supported, too. For details, see www.c64-wiki.com/index.php/SD2IEC
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