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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Illuwatar on January 22, 2009, 07:16:16 PM
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Got the ARM board from Yaqube this week and as usual - it took only a brief moment and it was installed:
(http://www.illuwatar.se/project_pages/minimig2/images/minimig20-008.jpg)
(http://www.illuwatar.se/project_pages/minimig2/images/minimig20-009.jpg)
(http://www.illuwatar.se/project_pages/minimig2/images/minimig20-011.jpg)
I got a beta-version of the firmware from Yaqube to verify. And it works really good including the hard file support and the overclocking features. Also, the new core supports the AD724 now with proper S-video output on my board. More to come...
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I should get mine soon :-)
Could you please list all the features of this board please and summarise what it can do?
What would this board allow us to do?
Thank you. :-)
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when can we normal people expect to order one ?
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Its a HD controller for running hardfiles on the SDcard.
Really nice Mini-ITX motherboard! :-)
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Out of interest, why does it require a hardware controller? Why can't the hardfile access be done in software? How does the controller interface with the rest of the board and make the hardfile support available?
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moto
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It's not a hardware controller. It is a plug in replacement for the original PIC that controls the SD functions. The HD support is in software. The problem is that the original PIC was not powerful enough to handle everything it was currently doing AND support hardfiles. We saw some pretty significant improvements to the PIC software from the time the minimig was originally produced and now. No doubt we will see more improvements with a more powerful processor replacing it. The first big improvement being hardfile support.
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Ahhh ok. So is the additional circuitry on the board just to make the new PIC compatible with the existing board?
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moto
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motorollin wrote:
Out of interest, why does it require a hardware controller? Why can't the hardfile access be done in software? How does the controller interface with the rest of the board and make the hardfile support available?
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moto
The original PIC is a slow processor (it gives less than 5 MIPS at 20MHz) and has very little RAM. So little that it cannot even cope with folders on the SD card.
On the other hand, the ARM processor is much faster (I reckon 18MIPS+) and has enough RAM to allow buffering of the read/write streams, and possibly support for folders on the SD card as well.
In Yaqube's video you can see around 400k transfer rate in SysInfo using the ARM processor. If using the PIC this would most likely have been 40k or less!
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Partly, it appears, but there is also a USB connector on the board, so I assume that that requires at least some circuitry. It is also possible that the ARM does not have everything in chip that the PIC does, so that could add circuitry. Someone would with more experience with the two would have to tall us that though.
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Belial6 wrote:
Partly, it appears, but there is also a USB connector on the board, so I assume that that requires at least some circuitry. It is also possible that the ARM does not have everything in chip that the PIC does, so that could add circuitry. Someone would with more experience with the two would have to tall us that though.
Well, the ARM has more peripherals than the PIC, though for this application, it's likely that use was made of onboard SPI and USB device. (Not USB host!) Obviously Yaqube could clarify on this. I'm merely speculating.
If you'd like to have a look, datasheets are here:
PIC18F252 (http://ww1.microchip.com/downloads/en/DeviceDoc/39564c.pdf)
AT91SAM7S (http://www.atmel.com/dyn/resources/prod_documents/6175s.pdf)
Mind you that Yaqube has mentioned previously that he plans to change ARM processor from an Atmel to a Philips LPC2388. The Philips part looks like a very nice chip. It has Ethernet, USB Device, USB Host, SD card interface, battery backed clock and lots of extra goodies!
Regards,
Edwin
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Yes, he has said before that the USB is used as a device and not as a host.
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I'm guessing too, but the USB port is probably to load firmware into the ARM. These days it's probably easier to add a USB port than a serial port. And smarter, since they're disappearing from peecees