A while ago when the Cortex Firmware was released allowing low cost USB floppy emulators to be used in Amigas there were initial plans to release further firmware updates allowing usage on Atari ST and Amstrad 3″ drives. Unfortunately for a number of reasons I won’t go into that never eventuated. However the creator of HXC Devices has stepped up to the plate and is offering HXC firmware updates to the Gotek devices which are compatible with Amiga, Atari ST, and Amstrad CPC.Unlike the Cortex firmware the HXC firmware requires a licence cost of 10 euro, which I consider a bargain as the firmware is constantly being updated and supported. Recently I have installed such a device into an Amstrad 6128.
Purchasing the hardware
The Gotek floppy emulator can be purchased from eBay. The prices do vary, and there are plenty of people “reselling” these with pre-installed firmware for tidy profits. Thats fine if you want to pay for convenience, however savings can be made doing it yourself. I recommend searching for “USB Floppy Emulator” rather than “Gotek” as the listing that mention Gotek in the description tend to be more expensive. You can also search for a model number such as SFR1M44-U100K.
You should be able to land a shipped unit for about $25 AUD. Most units are practically the same, with the major differences being firmware (which will be overwritten anyway) and number of LCD display panel digits.
You will also need a USB TTL serial programmer. You can buy these from eBay, and you should go for one that comes with header cables. These should set you back about $3 AUD posted.
Purchasing the software
To purchase the HXC firmware follow the instructions at http://hxc2001.free.fr/floppy_drive_emulator/. Essentially you need to send an email as per the webpage, and then you receive instruction on how to pay. You will receive details of how to download the software, and a username/ password for the download server.
Other items needed
For an Amstrad Gotek installation you will need a 34 pin IDC header because the Amstrad connection is a different size, and also some of the wires need to be shifted. You can get these easily enough from eBay, or at electronic retailers like Jaycar.
Preparing the Gotek device
Instructions are provided on how to program the firmware when purchase it.
To make programming the device easy install some header pins where indicated in the picture below. Note this requires soldering.
Follow the instructions provided to then install the software.
The first thing to do is install software using the serial bridge. This requires use of the USB TTL programmer. Connect the pins up as explained in the documentation.
So now it is time to set up the serial bridge. Launch the Serial Bridge software, and plug the programmer into a USB port on the computer.
Enter provided username & password, then click connect. Yo should receive a message saying the link is up.
Select the appropriate COM port. Note if you have several device set up for COM ports you will need to select the right one. Using a Windows computer, if you plug the programmer into the USB port it will search for a driver and install automatically, assigning a port in the process. Then click Open.
After a few seconds, you should receive a prompt saying the device is detected. If this does not happen, try momentarily bridging the reset pins as described in the documentation. If this still does not work, ensure you are using the correct username & password, or verifying you have selected the correct COM port by viewing the allocations in Device Manager. The seller of the software is very helpful, so if you get stuck you can message them for advice.
Providing you get past that point, click Program to begin. This installs software.
Once you are done, you can install the firmware at this point if you want to. Copy the firmware installer onto the root of a USB stick, and place it in the Gotek. Remove the jumper that puts the Gotek in programming mode, and you can also remove the TX/RX lines. The Gotek just needs the 5V supply. Then when plugging the USB programmer back into the PC, hold both button in for a couple of seconds and the firmware will automatically install. After it has finished, you will see the letters “hxc” providing you have a 3 digit display.
Installing the Gotek into the Amstrad 6128
Remove screws from the bottom of the Amstrad Case, and the side connecting the disk drive. Be careful when prising the top and bottom parts of the case apart due to the membrane ribbon connectors on the left hand side which need to be carefully removed. Take the disk drive out by disconnecting the drive cable and the power cable, and removing the 2 screws holding it in place.
The first thing to do is change the ribbon cable connector. There are various ways this can be done, with options for modifying the cable in a way where it can still be used for both 3″ and Gotek/ normal 3 1/2″ floppy drives. However as this is a spare Amstrad I have it will permanently use the Gotek as the drive, so I will do things the easy way.
Prise apart the existing cable connector by putting pressure on the tabs as shown. The once the back of the connector is removed, carefully prise the ribbon cable from the connectors.
You will then be left with the bare cable.
Carefully separate the 6 strands on the side with the red stripe on the right.
Now get your new 34 pin IDC connector, and carefully place place the ribbon cable in it. The main piece goes in starting all the way to the left. Then skip 2 pins, and place the part with 6 strands in. There should be 6 remaining empty pins to the right hand side. Make sure this is carefully lined up, and place in a vice and slowly tighten. This will ensure a neat even connection. See the photo below where you can see the gaps as described.
Now to the power cable. Be warned that the 12V and 5V lines are reversed on the Amstrad 3″ drive compared to a standard 3 1/2 ” drive. Once you swap to a gotek, you will no longer need the 12V supply.
Place a small jewellers screwdriver under the plastic ridge above the Red 12V connector. Prise it up while gently pulling back on the wire to remove it. Put the red wire out to the side. Now remove the orange 5V wire in the same way, and then place it where the red wire was. As we no longer need the 12V supply, place some insulating material over the red wire connector such as heat shrink tubing. Then to keep things neat keep it attached to the other wires with a cable tie.
The Gotek is not the same size as the previous 3″ drive, so some modification is required for a neat fit within the case. The best position for the Gotek is at the front as far right as it will go. However there are some items on the right hand side wall of the case in the way, as well as a mounting point plus small pin guide on the left. Rather than hacking up the Amstrad case, it is a better option to hack up the Gotek casing. See below I have cut out parts of the Gotek casing to fit against the side wall, and also cut out some of the case to fit over the mount point and pin guide.
After checking that it all fits nicely, the gotek casing will be mounted with double sided tape. Use good quality tape such as 3M brand and it will be a very strong hold which will last. Be careful when positioning the base with the adhesive exposed.
Now placing the top part of the Amstrad case back, there is a gap above the Gotek Unit. To neaten this up, I cut a piece of MDF to size to fill the gap, and attached some spare quality black adhesive vinyl to it.
Having confirmed the size and fit was right, this will be attached by again using quality double sided tap on the top part of the case.
The final thing to configure on the Gotek unit is to ensure the only jumper is in position SO. This is required for the Amstrad to load files.
All done, now time to reassemble the case. The gap filling works better than expected, and looks very good. Following instructions from the HXC website, copy the file manager program and config file to the root of a USB drive. You will need to convert .dsk files to .hfe using supplied software then put them on the USB stick.
To open the file manager, ensure slot 000 is chosen using the buttons on the Gotek unit. On the Amstrad type run “hxc to launch the file manager. The file manager is easy to use and has built in help. Assign disk images to slots. Don’t forget to save the image file assignments before exiting. Simply use the buttons on the gotek to select a particular slot and load it as if it was a normal disk. Now enjoy some Amstrad CPC games!