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Discussing the Open Source FPGA Amiga Project
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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Thu May 16, 2013 1:39 am 
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Joined: Wed Aug 08, 2012 12:44 am
Posts: 31
CHAOS....Not sure if this should be a new topic...but talking about disk access and R/W.... you know that IDEFIX upgrade that you can get for your A1200 that fits over the GARY chip, I think...it allows for PIO Mode 5...upto 15MB per sec maybe...not sure...I wonder if that logic could be added to the minimig. Right now, I only get about 900KB/sec on the minimig DE1 port...is that what every else is getting? Have to somehow figure out how to reverse engineer it...what logic is it taking over during operation...is it a complete redesign of the Gary chip...implementing all functions but just hijacking all of the on board GARY pins....

Anyway, just thought I would mention...have the HD file support is awesome as it is...but...just thought I would ask anybody else's opinions...definitely out of ability to implement it at this point in time...

Cheers!

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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Thu May 16, 2013 1:58 am 
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Joined: Wed Aug 08, 2012 12:44 am
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@Chaos....you know...I have 3 different DE1's and they all have different SDRAM chips, I think I checked a long time ago the first time that there was some deal with the different speeds causing problems...I can set them all up to use as a test battery for any test release you have...if you are in a hurry for feedback...

-Sjamaan

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~ Amiga 1200 030/42MHz ~ Amiga 500 010/7MHz ~ Altera DE1 with Minimig core ~ Amithlon (DELL GX260) GeforeceFX5200
Details of my projects: http://takuma-denpa.blogspot.jp/


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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Thu May 16, 2013 12:21 pm 
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Joined: Tue Nov 09, 2010 3:10 pm
Posts: 316
Hi,

sjamaan wrote:
CHAOS....Not sure if this should be a new topic...but talking about disk access and R/W.... you know that IDEFIX upgrade that you can get for your A1200 that fits over the GARY chip, I think...it allows for PIO Mode 5...upto 15MB per sec maybe...not sure...I wonder if that logic could be added to the minimig.

I don't know the details of how the Idefix Express works, but I'm guessing it provides buffering for the IDE bus and allows tighter IDE cycle times, which is basically what the PIO modes specify. I'd say you are still limited with Gayle's bus speed to memory. Plus, since this is Programmed I/O, the CPU more or less directly drives the data transfers, so the achievable speed is greatly dependent on the CPU speed.
There is no actual IDE bus in minimig, all transfers are done over the SPI bus and the IDE registers are emulated, so I don't think that anything much can be done here. Well, except writing a DMA IDE controller, but that would require a new driver (scsi.device), and I have nowhere near enough knowledge atm. to write such a driver.

Quote:
Right now, I only get about 900KB/sec on the minimig DE1 port...is that what every else is getting? Have to somehow figure out how to reverse engineer it...what logic is it taking over during operation...is it a complete redesign of the Gary chip...implementing all functions but just hijacking all of the on board GARY pins....

Yes, that speed is generally what is expected. The theoretical maximum frequency for SD cards with SPI bus is 25MHz, that means 25Mbit/s or a little under 3MB/s. Even with a perfect master, that speed is not achievable on real hardware. But there are things that can be done to increase the speed:
- get as fast SD card as you can find (although mostly all SD cards work at the same 25MHz frequency, there is a difference between them in what kind of delays they need between commands)
- increase the size of buffers in FPGA (as reading multiple blocks is much more efficient, a small increase in speed)
- instead of SPI bus use the 4-bit SD bus (this would require a compatible ARM controller & writing of a SD bus implementation in FPGA, would theoretically provide up to 4x speed increase)
- get (write! :)) a faster CPU for the Amiga - as described earlier, the transfer speed is greatly dependent on the CPU speed (unfortunately, there are no plans for a new, faster 68k FPGA core that I know of; however I am already - slowly! - working on a 68040-68060 type CPU for the minimig, but it will probably take me at least a year for any usable results, if I'll be able to do it at all)
- DMA IDE interface (would have to be written, but it is possible that yaqube has done something like that, if I read between the lines correctly ;))

Cheers!

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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Thu May 16, 2013 12:23 pm 
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Joined: Tue Nov 09, 2010 3:10 pm
Posts: 316
sjamaan wrote:
@Chaos....you know...I have 3 different DE1's and they all have different SDRAM chips, I think I checked a long time ago the first time that there was some deal with the different speeds causing problems...I can set them all up to use as a test battery for any test release you have...if you are in a hurry for feedback...

-Sjamaan

That's great! I only have two, with Zentel and PSC chips. I could use your help when I get back to updating the SDRAM controller and the cache, will let you know.

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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Sun May 19, 2013 7:08 pm 
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Joined: Thu May 09, 2013 11:32 am
Posts: 32
Pinball Fantasies "error" is not Minimig error, it cannot write highscores on WinUAE, too. WinUAE says "this software uses non standard disk format..."


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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Mon May 20, 2013 10:26 am 
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pik33: Thanks, that's good to know.

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 Post subject: Re: Write error #22 - minimig DE1 can't write to virtual dis
PostPosted: Mon May 20, 2013 1:14 pm 
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Joined: Mon Dec 01, 2008 9:58 pm
Posts: 1568
Location: .de
Turrican I/II and some other title also can't save any data to a standard ADF disk image.

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