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.

[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.

[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...

[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.

[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...