pdaehne/Atari-ST-5V-Cartridge
KiCad project and Gerber files for a Atari ST cartridge that provides 5V power to devices like Gotek or ACSI2STM drives
Atari ST 5V Cartridge
This repository contains the KiCad project and Gerber files for a simple Atari
ST cartridge that provides 5V power to external devices like
Gotek Floppy Drive Emulators
or ACSI Harddrive Emulators like ACSI2STM
via a single floppy power connector and two USB A ports.
Warning
I did test this cartridge with my own Atari 1040 STF. I do not own any other
type of Atari ST, so I do not know if the cartridge actually fits into Mega
STs, TTs or Falcons. Use at your own risk!
Warning
Using the cartridge port to supply power to external devices clearly is an
abuse. So use the cartridge carefully. Do not try to load the batteries of
your smartphone via the USB ports. This is meant as a dirty hack for low-power
devices like Goteks and ACSI2STMs. Pulling too much power might damage the
mainboard of your Atari ST.
Ordering the PCB
The subdirectory "gerber-files" contains a Zip file you can use to order the PCB
from PCB manufacturers like PCBWay or JLCPCB. Simply upload the Zip on their web
page. Order the standard PCB thickness of 1.6mm. I also recommend to order a
surface finish of ENIG with gold fingers and chamfered edges (if possible),
because it is much more durable than the default HASL finish.
Building the Cartridge
Bill of Materials
-
1x TE Connectivity AMP Connectors 171826-4.
This is the power connector usually found on floppy drives. It is also known
as a Berg connector. You can
get these from DigiKey or Mouser. There are cheap clones available from
AliExpress. Alternatively, you can also use a standard angled pin header with
four pins, but keep in mind that the pitch of the floppy power connector is
2.5 mm, while the pitch of pin headers is 2.54 mm, so they are not really a
good replacement. -
2x Molex 0676433910.
These are the two USB-A connectors on the cartridge. You can also get these
from DigiKey or Mouser, or cheap clones from AliExpress.
Soldering the Floppy Power Connector
Start with soldering the floppy power connector. I used an adhesive like
Blu Tack to stick the connector to the
PCB, soldered one single pin, and checked if the connector sits straight on the
PCB. Then, I soldered the other pins.
Soldering the two USB A Connectors
Next, solder the two USB A connectors. I used the same approach as for the
floppy power connector: I attached the connectors to the PCB using Blu Tack,
soldered one single pin, and checked if the connectors sit straight on the PCB.
Then, I soldered the remaining pins.
The last step is to solder the two clamps of each USB connector to the PCB. This
gives the connectors strength and prevents them from ripping off the board. You
will need a lot of solder and heat to fill the holes in the PCB completely.
Using the Cartridge
Warning
Before sticking the cartridge into your Atari ST, make sure the computer is
switched off, otherwise you might damage the computer!
Carefully stick the cartridge into the cartridge slot of your Atari ST. Make
sure that you insert the cartridge in the right orientation - the side of the
cartridge with the connectors has to face up, as shown in the image below.
Using the Floppy Power Connector
To provide power e.g. to a Gotek via the floppy power connector, you need a
cable with female floppy power connectors on both ends. These types of cables
are suprisingly difficult to find. I got mine from AliExpress, but it is quite
short.
Alternatively, you may use a simple jumper cable with female dupont connectors
on both sides. The 5V pin is the rightmost pin on the connector. There is no
need to connect the ground pins, there already is a ground pin on the floppy
signal cable.
The complete setup looks like this. The 34 pin floppy signal cable is connected
to an adapter that you can find in
one of my other repositories.
Important
Of course, the 12V pin of the floppy power connector is not connected on the
cartridge - the Atari ST cartridge port does not provide 12V. So do not try to
connect a device that requires 12V, e.g. old floppy drives.
Tip
Disconnecting cables from the floppy power connector is a pain, and you
quickly get dry solder joins. There is a hook on the connector that grabs the
socket on the cable from below. You can try to declamp that hook with a flat
head screwdriver that you carefully push between the connectors from below.
Using the USB A Ports
To provide power to devices with an USB port, e.g. ACSI2STM devices, use a
standard USB cable with a USB A connector on one side and a USB connector that
suits the device on the other side. The following picture shows how I connect
my ACSI2STM device build on a perfboard using a Bluepill with USB C connector:
The complete setup looks like this. The 20 pin ribbon cable is connected
to an adapter that you can find in
one of my other repositories.
Important
The two data pins of the USB connector of course are not connected on the
cartridge. You do not get USB functionality on your Atari ST! These USB ports
can only be used to provide 5V to other devices.
License
Atari ST 5V Cartridge (c) by Patrick Dähne
Atari ST 5V Cartridge is licensed under a
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
You should have received a copy of the license along with this
work. If not, see https://creativecommons.org/licenses/by-nc-sa/4.0/.