Denial

I'm currently reworking the design of the Final Expansion 3 cart in KiCad. Partly this is a learning exercise in how to use the program but I'm also planning to produce a slightly updated version incorporating the fix for the crosstalk issue that was done recently.

I'm using mostly SMD components, some parts are cheaper/easier to find in that footprint and, with a bit of patience, it's not that hard to hand solder them. It also makes the board layout less crowded.

One further change I'm considering: should the new design use a micro SD? Full-size SD cards are getting harder to source, and I've had problems with poor quality micro SD to SD adapters.

MicroSD makes sense IMO. Allows you to make a more compact design as well. Can you still source the CPLD?

tlr wrote: ↑Sat Aug 31, 2024 6:21 am MicroSD makes sense IMO. Allows you to make a more compact design as well.

That's another reason for going for microSD.

Can you still source the CPLD?

Mouser seem to have them available at a reasonable price (£3.50/€4/$4.50).

IMHO coupling storage with RAM expansion is unnecessary if not undesirable.
I don't think we'll ever have a "final" storage solution. SD2IEC has been impressively stable over the last ~15 years, but even today there are other, albeit C64-centric, options on the market.

That said, I do understand that the majority of consumers are attracted to a simple all-in-one solution, and micro-SD is totally fine
Fixing the cross-talk issue would be huge for the utility of the FE3. That sounds great!

For storage I prefer USB pendrives like in the 1541Ultimate2. I don't know if this brings technical issues.

It's much easier to interface with SD cards than with USB (A bit of bitbanging SPI vs an entire USB stack).

I prefer regular SD cards any day for that matter. micro SD is just too fiddly to use. And too easy to misplace and never to be found ever again

Here's my initial attempt at a schematic. I think it's reasonably neat given I'm new to KiCad (and schematic design in general).

Y1 should be 32.768 kHz.

Mike wrote: ↑Sat Aug 31, 2024 2:15 pm Y1 should be 32.768 kHz.

Oops, yes. Clock would be interesting otherwise.