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Beginners > Pogo Shell + UART cable

#20505 - jippie - Wed May 12, 2004 8:48 am

Hi,
I have been out the scene for a while. So maybe this is a dumb question.

When I first bought my GBA I also got a 256M flash advance card, that is programmed using the parallel port.

What I was wondering is now possible to upload roms/text etc. by UART cable an using the pogo shell?

thx

jippie

#20514 - Lupin - Wed May 12, 2004 12:11 pm

sure, you just have to upload the file system and the pogoshell binary to your gba and it should work as you want. You can't directly upload text files or pictures, you have to include them into the file system of pogoshell (you have to put the pogoshell binary at the start of the rom, then put all gba roms between the pogoshell binary and the filesystem - the filesystem comes last)
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#20516 - jippie - Wed May 12, 2004 12:26 pm

Ok then I go make myself a uart cable :)

thx again,

jippie

#20520 - Lupin - Wed May 12, 2004 2:03 pm

I don't really understand what you want to do now, do you want to upload pogoshell to the rom? Or do you want it to upload as multiboot using the uart cable??

Why don't you just use the rom you already have?
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#20531 - jippie - Wed May 12, 2004 3:19 pm

Lupin wrote:
I don't really understand what you want to do now, do you want to upload pogoshell to the rom? Or do you want it to upload as multiboot using the uart cable??

Why don't you just use the rom you already have?


Oh, now I'm a bit confused as well. From your mail you answered it(I thought :)

On the GBA I use pogoshell for displaying text and running homebrew games.
Now everytime I want to add/delete a new game or text. I have to rebuld the whole flash card and flash it via printer port.

What I would like to do is leave the flash card in the GBA and add new game/text via a cable.

I thought to use the UART cable as I have the parts to make one.

thx

jippie

#20579 - Lupin - Thu May 13, 2004 1:05 pm

Ah, now i understand :)

In theory this is possible, but in practice you will encounter some problems... First thing you do is build the cable and upload a rom to ewram, this rom will then accept the data from the communication port and write it to your cart, this means you will have to write the rom that handles the data/writing and for doing so you need to know what cart you own (the hardware specifications) because writing to flash carts is flash cart specific.

The problem with writing stuff onto the cart is a) that you can only write 256kb chunks of data and b) have to know where to put the data. A good way to solve both problems would be to create a file system like the gbfs and read out the filesystem information as you connect the gba with your PC (oh, you will also have to create a PC tool to upload the data to your gba).

This all sound more like a long term project, but sure would be great if you would be able to complete it :)

I wonder if it would be possible for someone to write a file system for the gba and then write a windows driver so that i can use my gba as a hard drive :)
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#20599 - tepples - Thu May 13, 2004 4:22 pm

If you want an external hard drive that's as big as a typical GBA flash cart, then go to Wal-Mart's computer section and look for USB pen drives.

I think the MBV2, F2A, and EZFA cables follow a routine like this:
Code:
PC sends start address and number of 32 KB blocks to GBA
for each block in the range or until failure:
  do 3 times or until hash matches:
    PC sends a block of data to GBA along with a simple hash such as CRC
    GBA computes hash of received data
  do 3 times or until data matches:
    GBA writes received data to the flash cart
    GBA reads it back from the flash cart and compares it

The two "do" loops can run concurrently. The step "GBA writes received data to the flash cart" will depend on 1. the flash cart's ASIC and 2. the flash chips' make and model. Because 2 is a commodity part, it may be easier to coax information about 2 from the manufacturer than 1, especially when the manufacturer in question is Borden.
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#20734 - jippie - Sun May 16, 2004 10:16 am

Lupin wrote:
Ah, now i understand :)

This all sound more like a long term project, but sure would be great if you would be able to complete it :)

I wonder if it would be possible for someone to write a file system for the gba and then write a windows driver so that i can use my gba as a hard drive :)


Hmm, you just killed it with this quote :)
I have too many long term project that never get finshed :(

So if anymore else would love tou have a go by all means go ahead :)

And good luck.

jippir