Inspired from the SNAC Accessory Converter and the IEC Support of the C64 Core
I created together with dtimber this little Adapter PCB for the MiSTer FPGA.
The Adapter converts the MiSTer FPGA User Port (Serial IO) into a Commodore IEC/CBM (Serial) Bus Port.
Use the Adapter to connect a real Commodore Floppy 1541 or compatible devices (SD2IEC/PI1541) to your MiSTer.
I know there are better and faster ways to load a game into a MiSTer's Core, but this is fun 🚀.
C64, C128, Commodore Plus/4
SD2IEC, PI1541, CBM 1541, CBM1541-II, CBM1571, CBM1581 and Printer MPS-803.
Cores and some Hardware Devices are also tested with JiffyDOS 🚀.
Double check the User Video below.
I used "breakout Parts" for the used Voltage-Levelshifter and the Voltage-Regulator as I had them in stock.
There is also a Full-SMD-Version available, created by dtimber who created the Case as well.
The first Picture shows the "Breakout Version", the second the "Full-SMD Version".
Changes:
- Added support for the SRQ Signal which is needed by the C128 Core for Fast Serial Mode.
The Breakout Version v1.2 need a second Leveshifter on Top of the first one to support the SRQ Signal.
Solder two small cables from the Pins LV5 and HV5 to one channel of the second Levelshifter. - Removed 5V support (R1-R4) which needs a Standard SNAC Adapter connected before SNAC2IEC.
The first Picture shows the "Breakout Version", the second the "Full-SMD Version".
The Case was designed to look like the C64 Power Supply
Connector View
Left Connector = IEC/CBM Bus, right Connector = 5V Power from SNAC Port
Soldered PCB Version with Level Shifter.
Use it with the Standard IO Board with SNAC Port and 3.3V Signal Level.
You need all parts except the "optional's".
Soldered PCB Version without Level Shifter.
Only usable with the "first" PCB Versions.
Use it with SNAC Port's with integrated Level Shifter or with blue212's external SNAC Adapter and 5V Signal Level.
Just add some 0R 0805 Resistors or a blob of solder to R1,R2,R3 and R4.
A look inside...
All Parts for the Breakout-Version
| Part | Type |
|---|---|
| R1-R4 | 0 ohm 0805 resistors (optional, see schematics) |
| C1 | 4,7uF 0805 capacitor (optional, see schematics) |
| J1 | USB3 type A connector |
| J2 | 6 pin DIN connector (MAS60) |
| J3 | DC barrel connector (optional, 5.5/2.1 mm should be fine for most PSUs) |
| U1 | 4-Channel Voltage-Levelshifter (5V/3.3V), add a second stacked Levelshifter for SRQ |
| U2 | 5V to 3.3V Voltage Regulator |
| Part | Type |
|---|---|
| R1-R4 | 0 ohm 0805 resistors (optional, see schematics) |
| R5-R12 | 10k 0805 resistors |
| C1-C3 | 22nf 0805 capacitors |
| Q1-Q4 | N-Channel SOT23 MOSFET transistors (BSS138 or similar) |
| U1 | 3.3v LM1117 SOT223 regulator |
| J1 | USB3 type A connector |
| J2 | 6 pin DIN connector (MAS60) |
| J3 | DC barrel connector (optional, 5.5/2.1 mm should be fine for most PSUs) |
| Part | Type |
|---|---|
| R1-R10 | 10k 0805 resistors |
| C1-C3 | 22nf 0805 capacitors |
| Q1-Q5 | N-Channel SOT23 MOSFET transistors (BSS138 or similar) |
| U1 | 3.3v LM1117 SOT223 regulator |
| J1 | USB3 type A connector |
| J2 | 6 pin DIN connector (MAS60) |
| J3 | DC barrel connector (optional, 5.5/2.1 mm should be fine for most PSUs) |
| Part | Type |
|---|---|
| Brass Nuts | M3, outer size 4,6mm, lenght 6mm |
| Screws | M3, Counter Sunk, length 17mm |
- dtimber was helping me with KiCad and he is the Creator of the Case and the SMD-Version.
- https://github.com/MiSTer-devel/Main_MiSTer/wiki
- https://github.com/MiSTer-devel/Main_MiSTer/wiki/User-Port-(Serial-IO)
- https://github.com/MiSTer-devel/C64_MiSTer
- https://github.com/blue212/SNAC
- https://misterfpga.org/
- https://misterfpga.org/viewtopic.php?t=4469
- https://youtu.be/zR52L662JqI
- https://www.youtube.com/watch?v=zR52L662JqI
- https://www.youtube.com/watch?v=jKdF6Q4ZU_g
- https://www.youtube.com/watch?v=Q-g8Mt_xXnU
- https://www.youtube.com/watch?v=LXGE7Ap88mE
