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Old 19 June 2019, 23:24   #21
Mick
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Has this been all tested then? (any pics?) is clearance with the keyboard okay when the Amiga is all put back together? it uses the same memory chips as used in the A600/A1200(rev1.x) right? I just got an A1k board and considering one of these instead of the old chips, it seems a lot better for reliability as there's 6 less chips to fail.

Last edited by Mick; 19 June 2019 at 23:30.
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Old 22 June 2019, 17:41   #22
katarakt
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Well, about the cipram replacement board ...these IS41C16257-35 are all listed (mouser) as obsolete

Does it fit with keyboard mounted in closed case?

Anyways, thanks for the replacement board.
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Old 23 June 2019, 03:18   #23
project23
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Kai has done some great designs, but most (all?) of his stuff is as yet untested. There may be some mistakes or issues that aren't ironed out yet.

Don't let that put you off - if you're keen to develop things like this then you should absolutely go ahead!

But as far as i'm aware they're not ready-to-go tried and tested designs.
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Old 24 June 2019, 21:02   #24
katarakt
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ok, thanks for info
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Old 03 July 2019, 22:20   #25
Kai
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PCBWay delivery came in today!





Everything lines up BANG ON! Pin spacings for the SOJ's and the DIP socket pins both nice and accurate

@Project23 - i'm going to be sending you one of these and some DRAM's if you want
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Old 04 July 2019, 22:04   #26
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Sweet.

My boards have gone to manufacture but this sort of converter will be great for the DIY community going forward.
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Old 12 July 2019, 00:26   #27
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Will there be a version for rev.5 boards with 16 ram chips?
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Old 15 September 2019, 15:43   #28
Kai
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Quote:
Originally Posted by katarakt View Post
Will there be a version for rev.5 boards with 16 ram chips?
Probably in the future, should be easy enough to adapt, or for someone else to fork the project.

Here's the rev0 DRAM board working in a v2.1 Amiga 500++ reproduction board, DIAGROM output for proof:



Rev 0.1a has moved the SOJ's further back into the dead space between the RAM & Agnus, as rev0 does NOT clear the keyboard if socketed, currently.
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Old 20 September 2019, 19:25   #29
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Very nice!!! Just want to say that you should move the soj rams near the edge between ram and aguns so that they keyboard fit. Is this on the A500++ picture the new rev ?

Ah, and where can i find A500++ ? I don't need it because i have project red, but it's good to know for others.
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Old 21 September 2019, 01:56   #30
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Great work Kai. Looks awesome
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Old 17 October 2019, 00:44   #31
Kai
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v3 Boards now available, and the gerbers are up on github.

https://www.pcbway.com/project/share...ent_Board.html
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Old 17 October 2019, 05:30   #32
esel
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How about a 4 Chip Version ?
So you will have 2 mb Chip and dont Need a trapdoor RAM expansion.
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Old 20 October 2019, 02:02   #33
Kai
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How about a 4 Chip Version ?
So you will have 2 mb Chip and dont Need a trapdoor RAM expansion.
Going to test this, hopefully just cascading them should work.
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Old 03 November 2019, 16:55   #34
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I've bought 5 PCBs each of the V2 & V3 boards.
The V2 board works perfectly in my A500++ board but teh V3 will not.
Booting from a 3.1.4 ROM just gives you a yellow screen and a reboot cycle. booting from DiagROM and running a extended gives a pass but there are graphical corruptions. I built two of the V3s and got the same results on both chips. I'm wondering if extending the track lengths to move the chips into the dead space has introduced some latency into the signals.
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Old 03 November 2019, 17:08   #35
cmorley
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Looks like a faulty memory chip to me. Diagrom has manual memory edit which you can use to view/edit memory and work out which chip is dead (if you know which chip maps to what memory region). Then replace that chip.
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Old 03 November 2019, 18:07   #36
Vypr
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Looks like a faulty memory chip to me. Diagrom has manual memory edit which you can use to view/edit memory and work out which chip is dead (if you know which chip maps to what memory region). Then replace that chip.
That's what I though too, so I built another one with different memory chips and got the same result.
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Old 04 November 2019, 11:10   #37
cmorley
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Is the donor RAM known good or sourced from China? It could well be you have several bad chips in the batch. I'd take the RAM from a working V2 board and try that on a V3 PCB.

If it is not the RAM then I'm intriuged to know what the fault is.
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Old 04 November 2019, 21:24   #38
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The donor chip was this:

https://www.utsource.net/itm/p/456204.html

I've just built another V3, same visual corruption, almost exactly the same pattern as well. it starts with a single strip of green dots about an inch from the left hand side of the screen and then gradually begins to appear in other locations.

I'm waiting for another batch of chips from a different source. COuldn;t find any suppliers that hd 416257's in stock so got some 416256's instead
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