The TeensyROM was designed with hand assembly in mind. While surface mount packages are used, they are the larger types (SOIC IC packages and 0805 passives). If you feel this is beyond your solder capabilities, assembled units are usually available at a fair price. If there are additional questions, feel free to contact me.
- Tools/materials needed:
- Soldering iron/Solder (lead-free or otherwise)
- Wire cutters (aka Side Cutters, Dykes)
- Tweezers
- Vice to hold work
- Small knife (ie Exacto)
- Workspace with good lighting and magnification
- Computer with USB and the Teensyduino app
- Parts listed in the TeensyROM BOM
- Including bare PCB Link to latest design at OSH Park
- These steps need to be done before assembling the TeensyROM and connecting to a C64/128 for the first time.
- Load the initial firmware to be used into the Teensy 4.1 module.
- This initial programming needs to be done using the Teensyduino app
- Update process is described in the General Usage Document
- Disconnect the Teensy module from USB
- The 5v/USB connection on the Teensy module must be cut so that the C64 won't back-feed power from USB, or vice-versa.
- Find the small jumper trace between two pads on the back side of the Teensy (see pic below)
- Carefully cut the trace with an Exacto knife
- After cutting, plug the module back in to USB to be sure the LED does not come on.
- This verifies that the trace is cut.
- The module will be supplied power from the C64/128 when fully assembled.
- BOM item # 1-6
- Observe pin 1 marking/orientation on the 5ea ICs
- Recommend tinning a single pad of each device and attaching first.
- Once placement looks good with single pin, solder remaining pin(s)
- BOM item # 7-10
- Place the PCB in a small vice with the top side up, being careful not to contact previously placed components
- Place 2ea 1x24 headers, 1ea 1x5 header, and 1ea 2x3 2mm header (BOM items 8-10) into the TeensyROM PCB with the longer pins facing down through the PCB.
- Place the Teensy module (prepared in previous step) on the pins making sure all 59 pins are showing through it.
- Solder all 59 pins from the top, taking care not to bridge or touch any components on the Teensy itself.
- Holding on to the Teensy assembly, turn the PCB over and solder a pin or two while holding it in place. Then solder the all the remaining pins from the bottom.
- Cut the protruding pins from the bottom so they don't interfere, scratch, or short.
- BOM item # 11-15
- Observe propper polarity:
- LED: Square hole=short lead=flat side=Cathode
- THM capacitors: '+' mark on PCA opposite '-' mark on caps
- PCB v0.2c: Neg side has square pad
- BOM item # 16
- Use thermal tape to attach heatsink to center of the microcontroller on the Teensy module.
- Make sure the heatsink is not contacting any pins or other components, such as the large capacitor near it.
Action/test | Signals tested |
---|---|
Programming Teensy first time | USB Device Port (part of prep step) |
Power up, Verify main menu | EXROM/ROML, IO1, R/W, Phi2, Data bus, address bus |
Verify Main LED on | LED orientation, series resistor |
Read SD card directory | SD card port operation |
Read USB Thumb Drive directory | USB Host port signals |
Synch time via ethernet | Ethernet signals |
Verify Ethernet LED on | Eth LED signal |
Run self test | Rapid emulated ROM reads |
Jupiter Lander | GAME/ROML |
Button press, restart | Button, Reset signal |
Run CCGMS/Swiftlink, AT command | NMI |
MIDI USB keyboard to Cynthcart | IRQ |