My SD/MMC interface project

[ferix]

I'm proud to present my new project, the SD/MCC card interface for old Amigas.

Some pics of the prototype:

A closer view from the top:

Another view from the bottom:

The yellow wire is a small modification for some odd mmc cards, but It works fine now
I coded some test programs, and I can say It works flawlessly.
I can get the SD/MMC card status and read or write to It without problems.
It can achieve up to 1Mbyte/sec. on an A500.

Now comes the hard work... to write a system driver.
Any tip or advice is wellcome.

Edit:
I forgot to say It plugs into the parallel port.

[mingle]

Nice work...

One question - any reason why the SD slot is on the underside of the card?

Seems like an excellent solution for those Amiga without a PCMCIA slot...

Are you going to make a production run of these? :-)

Cheers,

Mike

[ferix]

Nice work...

One question - any reason why the SD slot is on the underside of the card?

The card slot is for surface mount, and the board has only one layer, so the slot goes underside.

Seems like an excellent solution for those Amiga without a PCMCIA slot...

That's the point.

Are you going to make a production run of these? :-)

I have no time nor money to make a production run, but I'll free the schematics and the board layout.

[lauri.lotvonen]

Sounds very cool indeed, I always had so much problems with my A500 and null modem cable. This would make data transmission so much easier, like PCMCIA CF readers/writers.

[ferix]

Just a brief update of the post...

This is the log of one of my test programs:

Code: [Select]

-=[ MMC/SD interface test program ]=-
(C) 2010 by ferix

Initializing ports...Ok.
Initializing MMC/SD card...Ok.
Reading sector #0...Ok.
Read data:
fa 33 c0 8e d0 bc 00 7c 8b f4 50 07 50 1f fb fc
bf 00 06 b9 00 01 f2 a5 ea 1d 06 00 00 be be 07
b3 04 80 3c 80 74 0e 80 3c 00 75 1c 83 c6 10 fe
cb 75 ef cd 18 8b 14 8b 4c 02 8b ee 83 c6 10 fe
cb 74 1a 80 3c 00 74 f4 be 8b 06 ac 3c 00 74 0b
56 bb 07 00 b4 0e cd 10 5e eb f0 eb fe bf 05 00
bb 00 7c b8 01 02 57 cd 13 5f 73 0c 33 c0 cd 13
4f 75 ed be a3 06 eb d3 be c2 06 bf fe 7d 81 3d
55 aa 75 c7 8b f5 ea 00 7c 00 00 49 6e 76 61 6c
69 64 20 70 61 72 74 69 74 69 6f 6e 20 74 61 62
6c 65 00 45 72 72 6f 72 20 6c 6f 61 64 69 6e 67
20 6f 70 65 72 61 74 69 6e 67 20 73 79 73 74 65
6d 00 4d 69 73 73 69 6e 67 20 6f 70 65 72 61 74
69 6e 67 20 73 79 73 74 65 6d 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 03
06 00 06 0f e0 cc 65 00 00 00 9b 99 07 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa
Taken from a plain A500...

[countzero]

very nice work !

Is there any programmed logic there ? or do you drive purely on 68k ? I'll be looking forward to schematics !

[ferix]

very nice work !

Is there any programmed logic there ? or do you drive purely on 68k ? I'll be looking forward to schematics !

No, It's all made of standard TTL logic, and the 68k only has to read and write to the parallel port, so It's very fast.
The circuitry is a small SPI uart, and It takes advantage of the handshake capabilities of the CIA.
Just write a byte to the CIA's port B, and It will be sent through the SPI.

[Sourraund]

Great! I'm working on something similar

[Tajmaster]

This looks a great project, well done mate!! Maybe someone like AmigaKit could take on the design or work with you to finalise it for release. Id pay around £15 for one of these, I hope its cheap enough to manufacture

[yorgle]

Sweet!  Want!  

[ferix]

Great! I'm working on something similar

This looks a great project, well done mate!!

Sweet!  Want!  

Thanks

Maybe someone like AmigaKit could take on the design or work with you
to finalise it for release. Id pay around £15 for one of these, I hope its cheap enough to manufacture

I guess that my prototype had cost about 20€ (or less), but It's just a prototype, so It lacks too many things, like leds (for power and card access), etc...
There are many things to change before make a batch run, like the voltage regulators, the use of smd components, etc...

[ipod_sock]

Sweet! Want!

Ditto!

[save2600]

Really nice! I'd buy one for sure if it ever gets released. Be nice to hack one inside an A1000 too  :-)   I'm sure I have a gender changer or two that could come in handy anyway. lol

[yorgle]

Really nice! I'd buy one for sure if it ever gets released. Be nice to hack one inside an A1000 too  :-)   I'm sure I have a gender changer or two that could come in handy anyway. lol

That is EXACTLY what I want to do with mine.  Mount it internally in my A1000, with just a ribbon cable out the back to plug it in.  I just need to figure out where to put the card slot then.  I'd say the front, but i kinda need that 256k expansion on the front... and I still kinda need that DF0:

Heheh.

[amigean]

Great work!

I take it this will eventually support proper filesystem mounts? And what about booting from an SD card or starting an adf from it?

A way to overcome the awkard position of sd card slot would be to place the parallel connector on a ribbon cable, so one could bring the whole interface round to the front (for easier access). Add a nice plastic housing and we have a 21st century external floppy!