About the GOTEK
GOTEK is a floppy drive emulator which can be directly attached to computers instead of a normal floppy drive. The drives are popular and cheap additions to many 80s and 90s computers including the Amstrad CPC.
The basic Gotek has a 7-segment 2 digit display which shows the currently selected disk image, a USB socket for a USB memory stick, and 2 buttons to choose previous and next image.
There are additional mods that can be added:
- speaker (to simulate the sound of the read/write head stepping as heard in a real drive)
- eject button
- rotary dial (turn the dial to select the disc image)
- LCD/OLED display (this shows more information including the name of the image)
The most recent version of the GOTEK (SFRKC30.AT4.35, based on the AT32F435 chip) usually already comes with OLED display and rotary encoder but is also more expensive than the basic models.
In addition to the GOTEK you also need
- 5V power (e.g. USB power supplies will work - or you can use the monitor's 5V power output with a Y-splitter cable)
- a 34pin ribbon cable to connect it to the CPC (e.g. an old PC floppy cable which has both 3.5" and 5.25" connectors)
- connector cable to update firmware of the GOTEK (depends on firmware type)
CPC Disk images are put onto a USB drive which is plugged into the front of the Gotek. On the GOTEK a disk image is selected (via buttons or rotary encoder) and then the GOTEK behaves almost exactly as if it is a normal drive connected to the CPC with the disk being inserted.
There is only a small difference compared to a real drive with older models: the disc motor signal is not connected internally to the Gotek. This means the ready signal will be active even if the disc motor is off. The new model SFRKC30.AT4.35 can pass the motor signal and reacts (delayed if wanted) to it for the ready signal. See below for FlashFloppy firmware.
The GOTEK can replace the internal drive of the 664/6128, e.g. if the internal drive is broken. Or it can be used as the external drive B. It can even work as a 3.5" or 5.25" drive for example with Parados or VDOS.
Firmware Update
Before the GOTEK can be used with the Amstrad CPC it needs to be flashed with a custom firmware.
The process depends on the type and firmware and is documented on the homepages of the respective firmwares (see below).
HxC Floppy Emulator firmware
There is a version of the HxC Floppy Emulator firmware that can be used on the Gotek. It must be purchased from the HxC website and can then be installed and used.
The firmware supports multiple computers and their disk image formats as well as the HFE v1 & v3 file formats.
Once the firmware has been installed into a Gotek it can be updated through the USB memory stick.
FlashFloppy firmware
FlashFloppy is probably the most popular firmware for the GOTEK. It's well supported by the author Keir Fraser and completely free.
The firmware supports multiple computers and their disk image formats.
Firmware installation is more easy than HxC firmware and only needs a USB-A to USB-A cable and the use of the original software of the microcontroller vendor to install the firmware. The process is very well documented on the FlashFloppy wiki.
Once installed further updates can be performed via the USB memory stick.
On the CPC, the following FF.cfg setting can be recommended:
# Floppy-drive interface mode interface = shugart # Host platform host = unspecified # Pins 2 & 34 output (drive->host) manual configuration pin02 = high pin34 = rdy # Rotational offset of disk after a track change track-change = realtime # Rotational offset of disk after draining a write to Flash write-drain = realtime # Index pulses suppressed when RDATA and WDATA inactive? index-suppression = yes # Milliseconds from head-step start to RDATA active. head-settle-ms = 12 # Milliseconds delay from motor-on to drive ready. motor-delay = 200
The rest of the settings can be used to your liking as they depend on preference and not on hardware emulation.
Models
The best Gotek to buy currently (12/22) is the Model SFRKC30.AT4.35.
This model features a Artery AT32F435 APU and as well a motor jumper. This completes the emulation as it simulates the motor spin-up time. They are usually offered with Rotary encoder and with OLED display.
On the CPC also the AT32F415 models can be a good alternative. They are cheaper and can be upgraded with rotary encoder and OLED display.
For full details on which models to use and which to avoid, see here: Gotek models on Flashfloppy wiki
Physical connection
CPC 464 / DDI
You can directly connect the GOTEK to the DDI-1 cable connector however you would need to cut off the noses on the bottom of the cable - or you use a short IDC extension cable to avoid cutting of the noses. Please keep in mind that the DDI-1 is powered by the original FD-1 3" drive so you still need the FD-1 or need to power the DDI-1 via an alternative method.
CPC 664 / 6128 external
A 34 pin IDC floppy cable as used in old PCs is perfect. If it even has a 5.25" edge connector you can use it directly.
For German Schneider/Amstrad 6128 models you will need a Centronics connector instead of the edge connector.
The 6128 Plus also needs a Centronics connector but with a slightly different pinout.
For full details look here: DIY:Floppy_Drives#Multi-Adaptor_Cable_for_External_Floppies_.2F_HxC_emulator
Replacing the drive in a CPC 664 / 6128 or FD-1
As connections are slightly different from a 3.5" drive the connections to the GOTEK need to be modified to replace a 3" disk drive in the original 664/6128 or FD-1 case. Also, as the size of a GOTEK is different from a 3" drive a (usually 3D printed) frame is required to hold the GOTEK in place.
- adapt the 26 pin floppy cable of the CPC to fit to the 34 pin connector on the GOTEK - 26 to 34 pin adapter
- switch 5V and 12V on the power connector as otherwise you would fry your GOTEK with 12V
- set the jumper on the GOTEK from S1 to S0.
- put the GOTEK into a (3D printed) frame to properly fit into the 3" drive slot
Note: If you remove the 3" drive from the CPC it no longer needs the 12V power supply. This means you can now use a single 5V power supply to run your CPC, including the MP-1 or CTM640 for the 464.
adapters
There are prebuilt adapters that can be plugged into the rear of the GOTEK and provide connectors for the 3" connector cables. These can usually be bought on Ebay.
Alternatively DIY adapters can be done easily. Make 100% sure that you don't accidentally connect the 12V to the GOTEK as this will definitely fry your GOTEK.
Gotek mod
If you don't plan to use the GOTEK on any other machine than the CPC you can also make a few modifications to the GOTEK directly and can use the original cables without modifications or adapters.
- cut the pin that is labelled as 5V on the GOTEK. Either the whole pin on the side of the drive, so only 3 pins remain or a little more subtle on the backside of the connector so there's a gap between the pin and the PCB. This ensures 12V is no longer fed into the GOTEK.
- make a connection from pin 1 to pin 4 of the power connector on the backside of the PCB to connect the GOTEK to the 5V coming from the CPC.
- optionally: remove the first 4 pairs of the 34pin connector. Either just cut the pins or desolder them if you have the equipment. This step is not mandatory as you can just connect the cable to the outer most part of the connector.
- make a small bridge on the backside of the GOTEK PCB between pin 8 and 10.
- optionally: cut the trace on the PCB next to pin 10. Alternatively remember to NEVER close S0 on the GOTEK (or cut the S0 pins).
- set the jumper on the GOTEK to S1
Now you can connect the original cables directly to the GOTEK as if it was built for the CPC.
HXC Manager
Despite its name this software works with both FlashFloppy and HxC firmware.
Especially when using the 3 digit display the HxC Manager offers a great alternative to organise and mount DSK images. You can select 20 images and assign them to 20 slots which you navigate via the up/down buttons on the GOTEK.
