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Author Topic: SD card interface (Read 342620 times)

Offline Saint

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Re: SD card interface
« Reply #90 on: 2014.March.16. 22:24:25 »
Very nice job! Dd you end up using a CPLD to handle the SPI interface?

I'll get back to trying to track down why my flash isn't reading from the z80 again next week... :)

I'll still develop mine as I still like the idea of an 'all in one' expansion which would allow a standard ep64 to run all software. So RAM upgrade plus flash and SD interface.

Great to see more new hardware for the old Enterprise. :D

Offline Z80System

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Re: SD card interface
« Reply #91 on: 2014.March.16. 22:35:38 »
Quote
I'll still develop mine as I still like the idea of an 'all in one' expansion which would allow a standard ep64 to run all software. So RAM upgrade plus flash and SD interface.
And finally which direction did you choose for the connection ? Will it be an inside expansion, like the RAM expansion, or a right side expansion port device ? (Zozo said the cartridge placement direction is dropped.)
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Offline gflorez

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Re: SD card interface
« Reply #92 on: 2014.March.16. 22:37:25 »
Ah, now I understand you. You are right, but in the comments of the article Zozo is "threatening" with a Fat16 operating system surely compatible with it... Plain SDs before the actual SDHC or SDXC can access up to 2Gig(or 4Gig with tricks), enough for the EP.
----------------------
Ah, ya entiendo. Tienes razón, pero creo que Zozo ya ha "amenazado" con un sistema de ficheros FAT16 que ya si que sería compatible.... Las tarjetas normales SD(antes de las actuales SDHC o SDXC) pueden manejar hasta 2Gig(o 4Gig con trucos), suficiente para el EP.
« Last Edit: 2014.March.16. 23:02:44 by gflorez »

Offline Saint

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Re: SD card interface
« Reply #93 on: 2014.March.17. 10:29:16 »
Quote from: Z80System
And finally which direction did you choose for the connection ? Will it be an inside expansion, like the RAM expansion, or a right side expansion port device ? (Zozo said the cartridge placement direction is dropped.)
I plan to do both an internal expansion and a plug in expansion port card. I like the idea of a single card which will allow any Enterprise (128 or 64) to run any software designed for 128K RAM or more. So this means it has to be either internal or on the expansion port to give the additional RAM at F8-FB. The internal card is more for me than anyone else, as prefer to be able to run the machine with no expansions plugged in... it just looks neater. :)

Offline Z80System

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Re: SD card interface
« Reply #94 on: 2014.March.17. 10:45:56 »
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The internal card is more for me than anyone else, as prefer to be able to run the machine with no expansions plugged in... it just looks neater. 
No, you are wrong, when they will be available (at a price I can pay) I would like both of them too, because of the reasons you mentioned.

One of them is good for EPs what you don't want to assemble, and one of them is good for final assemble, for a nicer EP.

Cartridge version would be the megaultimate version, beacause that would provide both of the goodness. But Zozo said yesterday, the cartridge unfortunately can have only four segments of memory ...
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Offline Zozosoft

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Re: SD card interface
« Reply #95 on: 2014.March.17. 11:20:30 »
Quote from: Saint
using a CPLD to handle the SPI interface?
He wrote in the Hungarian forum: it is a Xilinx CPLD.

Offline Saint

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Re: SD card interface
« Reply #96 on: 2014.March.18. 21:16:12 »
I wired up the 29c020 to the internal memory expansion and reprogrammed the GAL for 64KB at 40-43, and it boots fine. There must be some crosstalk I guess on the "big mess of wires" that is my prototype causing some random noise.

Ah, well, I'll just get on and create a proper PCB instead then!

Offline Saint

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Re: SD card interface
« Reply #97 on: 2014.March.18. 21:49:52 »
Zozo -- would it be easier if I created the internal expansion first? Once I have one built and some code written to access the SD card, I will send you one to write the EXDOS driver.

If I build the internal expansion first then you can still use EXDOS or any other storage device on the expansion port to help test and code.

Let me know what you think...

Offline Z80System

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Re: SD card interface
« Reply #98 on: 2014.March.18. 21:58:02 »
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If I build the internal expansion first then you can still use EXDOS or any other storage device on the expansion port to help test and code.
Zozo probably has expansion port splitter cards, with what you can connect multiple expansion port carts to the EP ...
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Offline Z80System

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« Last Edit: 2014.March.19. 10:39:35 by szipucsu »
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Offline Zozosoft

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Re: SD card interface
« Reply #100 on: 2014.March.18. 22:05:02 »
Internal or external also OK for me :-D

Offline gflorez

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Re: SD card interface
« Reply #101 on: 2014.March.20. 05:05:04 »
This is some out of topic here, but I have received a WIFI SD card I ordered. The brand is Transcend, the 16G model.

As it is greater than 4Gig it is formated to FAT32, but I`ve managed to partition it to four 4Gig partitions formated to FAT16. Then I had mixed results, as only the first division is recognised, but the WIFI side reads perfectly the content of the card, that can be acessed remotely. I have inserted it on a camera and the SD card sends pictures to my android phone via the App suited.

The system is intended for digital cameras and so it is a bit limited, but it allows transfering any type of files than only Jpeg or Mov.

Next tests are: first to do a little FAT12 partition, and second to connect it properly to Windows, not only by web page.



Offline Zozosoft

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Re: SD card interface
« Reply #102 on: 2014.March.20. 08:54:49 »
So then the Wifi SD not a Wifi for the host, just a dual access (local/network) storage?

Offline gflorez

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Re: SD card interface
« Reply #103 on: 2014.March.20. 16:33:39 »
It appears like this  small little card has inside an ARM processor at 400Mh running a Linux environment, but has been castrated to only permit  to do a few things with few file types, and only in one way. There are people actually working on hacking it. Some claim have already got root, but this scene is only in its beginnings.


On this page you have more information.

Offline gflorez

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Re: SD card interface
« Reply #104 on: 2014.March.20. 17:23:06 »
Quote from: Zozosoft
So then the Wifi SD not a Wifi for the host, just a dual access (local/network) storage?
Only permits transfer files from the camera SD-card to the up to three devices connected, only that way (I was wrong), but it can be inserted on a card reader on a device and allows to add files to the card.

Just the stock card has little use for the future SD card interface(we need traffic in both ways), but the panorama can change as the card is poorly protected...

The only proved fact is that the system works FAT16 formatted, but you lose part of the storage (is better to buy the same but 8Gig wifi card, as you only lose half).

I bought this card for use in the HXD, which has no problems with FAT32, but better meanwhile I'll use it on a camera...