ALPHA MODIFICATIONS

Post by **exxos** » 27 Sep 2018 16:47

Forgottenmyname wrote: 27 Sep 2018 16:22 If you've kept up, your board should now look a little something like this :)

*real* computing this is :thumbup:

Post by **Icky** » 27 Sep 2018 22:50

Forgottenmyname wrote: 27 Sep 2018 16:22 If you've kept up, your board should now look a little something like this :)

P.s. not done the 16mhz mmu fix as it was optional.

:coolpics: - Looking good.

PaulJ · Post by **PaulJ** » 29 Sep 2018 15:17

Icky, I'm putting in missing pullups on cpu. Your picture with the extra sip pullup pac shows a pullup connected to pin 10 (dtack) but nothing on pin 9 that is identified as needing a pullup. Initially I put the extra pullups in according to your picture but dtack then reads ~680 ohms which means the 1k pullup is ther and the 2.2 k is in parallel with it. Did you get the rw pullup on dtack or am I a marble short of a full deck?

Paul

Post by **exxos** » 29 Sep 2018 17:43

Looks ok to me...

11111111.JPG

DTACK is on RP1 (1K) so doesn't need a pull up, Icky doesn't have one on that pin, its RW.

PaulJ · Post by **PaulJ** » 29 Sep 2018 21:32

Your right, I'm one marble short. The prior picture is 90 degree different and I've been looking at it from this perspective.

Paul

Post by **Icky** » 01 Oct 2018 08:20

PaulJ wrote: 29 Sep 2018 21:32 Your right, I'm one marble short. The prior picture is 90 degree different and I've been looking at it from this perspective.

Paul

Hi Paul. Nice to see you working on the board.

Why not open a topic for your pics and experience in the Alpha User Builds section. https://www.exxosforum.co.uk/forum/viewforum.php?f=64

We would like to see where you are and some photos.

PaulJ · Post by **PaulJ** » 01 Oct 2018 15:42

I'll put something up later today.

PaulJ · Post by **PaulJ** » 02 Oct 2018 17:54

Do we need another pullup on BGACK pin 12 on processor. Once SJ1 is shorted it connects the 4.7k pullup on GLUE_BGACK (pin 40)? I may just change R150 to 2.2k?

Please advise..

troed · Post by **troed** » 08 Oct 2018 16:43

Is the description for RESET FIX complete? Icky has moved the leg of the resistor which is not in the description, but without it the cut tracks don't really make sense.

edit: Ah, read further down. Also the resistor connects to internal plane I guess. I'm not used to 4 layer boards ;)

Post by **exxos** » 08 Oct 2018 16:50

PaulJ wrote: 02 Oct 2018 17:54 Do we need another pullup on BGACK pin 12 on processor. Once SJ1 is shorted it connects the 4.7k pullup on GLUE_BGACK (pin 40)? I may just change R150 to 2.2k?

Please advise..

There is already a pull-up on it so it resistor is not needed as previously thought..

ALPHA MODIFICATIONS

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