FE3 respin - SD or micro SD card?

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srowe
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FE3 respin - SD or micro SD card?

Post by srowe »

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.
tlr
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Re: FE3 respin - SD or micro SD card?

Post by tlr »

MicroSD makes sense IMO. Allows you to make a more compact design as well. Can you still source the CPLD?
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srowe
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Re: FE3 respin - SD or micro SD card?

Post by srowe »

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).
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Wilson
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Re: FE3 respin - SD or micro SD card?

Post by Wilson »

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 :D
Fixing the cross-talk issue would be huge for the utility of the FE3. That sounds great!
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javierglez
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Re: FE3 respin - SD or micro SD card?

Post by javierglez »

For storage I prefer USB pendrives like in the 1541Ultimate2. I don't know if this brings technical issues.
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Re: FE3 respin - SD or micro SD card?

Post by groepaz »

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 :)
I'm just a Software Guy who has no Idea how the Hardware works. Don't listen to me.
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srowe
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Re: FE3 respin - SD or micro SD card?

Post by srowe »

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).
FE3ng.png
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Mike
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Re: FE3 respin - SD or micro SD card?

Post by Mike »

Y1 should be 32.768 kHz. :)
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srowe
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Re: FE3 respin - SD or micro SD card?

Post by srowe »

Mike wrote: Sat Aug 31, 2024 2:15 pm Y1 should be 32.768 kHz. :)
Oops, yes. Clock would be interesting otherwise.
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