Parts Substitution¶
Pi Picos Without Headers¶
The parts lists of Build With Soldering and Build Without Soldering both have Pi Picos with headers, which need no soldering. If you prefer to solder the headers yourself, these are the part numbers of the Pi Picos without them.
Qty |
Reference |
Description |
Mfr Name |
Mfr Part Number |
Mouser Part Number |
|---|---|---|---|---|---|
1 |
U2 |
Raspberry Pi Pico 2 W no headers |
Raspberry Pi |
SC1633 |
358-SC1633 |
1 |
U4 |
Raspberry Pi Pico 2 no headers |
Raspberry Pi |
SC1631 |
358-SC1631 |
4 |
U2, U4 |
Pico 20 Pin Header (2 per Pico) |
Amp |
10129378-920001BLF |
649-1012937892001BLF |
Substitutions¶
The WDC W65C02S and W65C22S must not be substituted. Don’t try NMOS chips (the ones without the C in the part number). Some older CMOS designs may work, but there are no plans to support out-of-production ICs.
Only Raspberry Pi’s own Pico 2 has been tested. Both the original and the “H” (header) versions work great. Pin-compatible alternatives usually work too.
The parts list specifies a Pico 2 W for the RIA. Its radio adds Wi-Fi and
Bluetooth. A Pico 2 without the W runs the RIA without them, flashed with
rp6502-ria.uf2 in place of rp6502-ria-w.uf2.
All resistors are 1% tolerance or better, any power rating. Leads must fit 0.8 mm plated holes spaced 10 mm apart. A size of roughly 0.1” x 0.25” (2.4-2.6 mm x 6-8 mm) is recommended.
0.1 μF ceramic capacitors come in axial packaging (like resistors), but classic radial (disc) capacitors work just as well if you prefer them. Leads must fit 0.8 mm plated holes spaced 10 mm apart. Any rating of 10 V or higher is fine; tolerance and temperature coefficient don’t matter.
Yes, 47 μF ceramic capacitors are pricey, but you only need two, and they never leak. Leads must fit 0.8 mm plated holes spaced 5 mm apart. Any rating of 10 V or higher is fine; tolerance and temperature coefficient don’t matter.
The CUI audio jack comes in many colors and with optional switches. The switches go unused, but the board accepts the extra leads.
The REBOOT switch is made by several manufacturers in various lengths, colors, and actuation forces. Nothing matters except that it’s “momentary on”.
The VGA jack is made by several manufacturers. This style has been around since the beginning, so if it looks like it’ll fit, it probably will. Newer VGA jacks are designed to save PCB space or to be oven-soldered; they look different enough to spot and avoid.
The 74xx ICs must be true CMOS. Use AC or HC, never ACT or HCT. Two of the three must be AC to reach 8 MHz. You can substitute 74HC00 and 74HC02 for the AC parts, but then 8 MHz is off the table. I’ve never seen a DIP 74AC30, but if you find one, prefer it over the 74HC30.
The RAM IC is 128K because two 32K chips cost more. Speed must be 70 ns or faster to reach 8 MHz.