My floppy emulator has not yet arrived and I have some time to spare so I need to find a way to get software on and off this machine. I could use the cassette port but thats too easy so I need to access one of the ports. The printer port is only an output, the floppy is controlled by the floppy disk controller so would require a long winded deciphering process to use it, so that leaves the expansion port.

My idea is to hook up a micro controller and access the computer  via a serial connection, or spi or  ic2 or give access to a sd card or lcd display. I looked around online for a information on the expansion port like this http://www.cpcwiki.eu/index.php/Connector:Expansion_port But how do you get data to it from the CPC, after a bit of research I found out you use the IN and OUT commands of basic or assembly. 

During my research I came across a project that is similar to what I wanted, some one had resently built a serial port using a Pic micro controller and a few other components, heres the project : http://retroworkbench.blogspot.com/p/universal-serial-interface-for-amstrad.html .I had seen other projects using a bunch of ic or using an FPGA, but this used a micro, a  4002 logic IC, a transistor and a few other components, I had a 4002, game on!

I needed an edge connector, they are not common anymore, the local Jaycar didnt stock them, the local computer store laughed at me ( I asked for a floppy cable with an edge connector, they claimed to have lots of cables), I found a 50pin edge connector on ebay but it turned out to be the wrong pitch, I eventually ordered one from the USA, Digikey. This would take some time to arrive so I looked for an alternative, what about a PCI slot connector from a motherboard,  Ive got a few boards that I harvest parts from but they are bigger and have a lot more pins, but lets give it a go.

I cut the connector from the board with a rotory tool and checked it against the 6128 for size, it too long but I can cut it.  The connector has 124 pins, and soldered onto the board through holes, it cant be desoldered by me, I have to cut the borad so I have less solder joins per piece of board. The pins are interleaved and make diagonal rows of 4 pins, if I make diagonal cuts Ill have four pins per piece of board to desolder.  This worked but I couldnt desolder 4 pins per piece, I made a cut down the middle so I had 2 pins per piece then tried for one pin per piece by making another cut but the force of the spinning disk ripped the pins off.  I could still use the connector so I left it at 2 pins per piece and remove all the board, cut the connector and check contacts with the 6162 expansion port, all good.