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Floppie209 / Amiga2000-remake

A recreation of the Amiga2000 motherboard using Sprint Layout
Creative Commons Zero v1.0 Universal
98 stars 22 forks source link

C1_and _R2 #4

Open rgbwalker opened 3 years ago

rgbwalker commented 3 years ago

Hi!

On a pcb "Amiga 2000 Remake Rev 1.8.5", while I solder the passive components I have a doubt about C1 and R2 as picture shows: C1_R2 It is sharing node with FB906, (as the main file show FB906 is unpopulated, ok), but the C1 and R2 must to be soldered as a serial? As show the silkscreen?

C1 and R2 sharing a soldered terminal "on air"?

What value for the R2? 68 Ohm?

Thanks in advance!!!

PeteDWard commented 3 years ago

Hi,

Not started my build yet but either side/node of FB906 are ground and doing a continuity test confirms that.

As for R2 and C1, after some investigating on Google etc these should be connected inline as per the silk screen. There is a blog post that you may find useful https://wordpress.hertell.nu/?p=1029 btw.

Hope this helps

rgbwalker commented 3 years ago

Thanks for the help!

Ok, no doubt about FB906, (on the Github project main file is explained, FB906 is unpopulated), And as you say, on the wonderful John Hertell´s web: https://wordpress.hertell.nu/?p=1029 are some pics, and is posssible to show something about this components. But the PCB used by John Hertell this time is Rev 1.6 and my PCB version is 1.8.5. Here is may doubt, is the same on both version?

I supose is the same, but im not sure.

I found this interesting web: https://retrohax.net/amiga-2000-codename-tesseract/ with an article about the same PCB version (Rev 1.8.5), it is possible to show some pics, with this components, with the doubts between R3 and R215 too.

Thanks for your answer!

rhaamo commented 3 years ago

The mod is for the 6.2 original rev, the PCB version of this repo don't mind. and effectively they are soldered "in the air", 270pF and 68ohm from CPU E line to GND, FB906 is left unpopulated. image

rgbwalker commented 3 years ago

Hi rhaamo again!

No doubt! I will solder C1 and R2 as silkscreen shows with a common leg on the air.

Thanks!!!