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Old 06 June 2018, 09:09   #381
fpmpaolo
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Quote:
Originally Posted by 8 Bit Dreams View Post
Yes
but it will be discussed in other thread, if author decides to do it, not here
Who is the author, if I can ask?
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Old 10 June 2018, 00:10   #382
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Originally Posted by PeteAU View Post
That's keirf's systest: https://github.com/keirf/Amiga-Stuff
You can download a bootable ADF there, it's good stuff for h/w testing.

I can't find the bootable adf ...where is it

edit: ah, found it
https://drive.google.com/open?id=0B6...GhXMWRvOXVDd3M

Last edited by katarakt; 10 June 2018 at 00:15. Reason: Found it
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Old 10 June 2018, 00:13   #383
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I can't find the bootable adf ...where is it
Look under the first header 'SysTest Binaries'. It has a link to Google Drive.
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Old 04 July 2018, 11:25   #384
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Would this type of RAM work?

I can source myself a memory with 4 of these on. Would that work?

4 pcs NEC 4218160-60 42-pin (2 x 21) chip on a 8MB EDO module.

Datasheet says 16 M-Bit Dynamic RAM, 1 M-word by 16-bit fast page mode, byte read/write mode, 5V power supply.

Thanks.


Last edited by Andreaux; 04 July 2018 at 11:42.
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Old 04 July 2018, 19:05   #385
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Yep
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Old 05 July 2018, 12:58   #386
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Is there a way to use this trapdoor expansion along with MegAChip/similar to get to full 2mb Chip + some Slow RAM in A500 (rev 5, if that matters)
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Old 05 July 2018, 14:03   #387
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Is there a way to use this trapdoor expansion along with MegAChip/similar to get to full 2mb Chip + some Slow RAM in A500 (rev 5, if that matters)
I have the same question but for a rev 6

and also other question. in your expasion design there aren't memory buffers, are they not need? like commodore did on the original design of a500 memory expasion?
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Old 08 July 2018, 14:28   #388
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dont think this is possible with this design.


You will need this:


http://eab.abime.net/showthread.php?t=93130
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Old 08 July 2018, 14:56   #389
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dont think this is possible with this design.


You will need this:


http://eab.abime.net/showthread.php?t=93130
Hi esel, I saw your project, but I still have my doubt. Since your adaptor dosent have memory buffers, ist needed?
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Old 09 July 2018, 11:01   #390
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Originally Posted by 1NOM155 View Post
Hi esel, I saw your project, but I still have my doubt. Since your adaptor dosent have memory buffers, ist needed?
By "memory buffers" do you mean the resistor packs on an A501?

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They are required to reduce voltage undershoot (& overshoot) at the RAM chips (worse on early Amigas rev3 & rev5). Undershoot & overshoot can affect reliability and if too great will damage the RAM (which is why they are fitted on the Commodore A501).
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Old 09 July 2018, 15:24   #391
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When I try to test memory with MBRTest-2 v1.22, it reports "Inhibiting mounted volumes..." and doesn't do anything
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Old 09 July 2018, 18:31   #392
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Quote:
Originally Posted by cmorley View Post
By "memory buffers" do you mean the resistor packs on an A501?

Attachment 58772

They are required to reduce voltage undershoot (& overshoot) at the RAM chips (worse on early Amigas rev3 & rev5). Undershoot & overshoot can affect reliability and if too great will damage the RAM (which is why they are fitted on the Commodore A501).
Hi Cmorley,

Sorry for my late response. I'm refering to the CAS and RAS signals, also refer as Refresh "Feature" by Commodore, using a 74F27, 74F86 and a 74LS163A or 74ACT00 and 74ACT273 by Techtravels.

You can find more information by those links http://www.amigawiki.org/dnl/schematics/A500_R6.pdf by Amigawiki.org and or https://www.techtravels.org/a500-dram-card/ by Techtravels.

I know you made some refresh in your GAL program, my doubt is they will work like Commodore design?

regards,

1NOM155
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Old 09 July 2018, 19:36   #393
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Originally Posted by 1NOM155 View Post
Sorry for my late response. I'm refering to the CAS and RAS signals, also refer as Refresh "Feature" by Commodore, using a 74F27, 74F86 and a 74LS163A or 74ACT00 and 74ACT273 by Techtravels.

OK, I follow.


Yes the OCS Agnus only generates refresh on (BDR)A0-A7 and not A8, hence the extra circuitry. Not all DRAM chips require the same refresh row count but many xx256 need all 512 rows visiting hence the extra logic for A8 refresh generation on A501.


So if you have an OCS Agnus and fit RAM which require 512 rows refresh then you will have a problem. ECS Agnus generates A8 on refresh I understand.


My board uses CBR refresh (CAS before RAS) to solve the problem, so it works with OCS or ECS the same.


Chris
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Old 09 July 2018, 21:08   #394
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Pete,
Are any of the Gerbers you have linked to here the same as the ones you use to make the expansions you are selling on eBay?
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Old 11 July 2018, 01:16   #395
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Nice mate doubt solved
Quote:
Originally Posted by cmorley View Post
OK, I follow.


Yes the OCS Agnus only generates refresh on (BDR)A0-A7 and not A8, hence the extra circuitry. Not all DRAM chips require the same refresh row count but many xx256 need all 512 rows visiting hence the extra logic for A8 refresh generation on A501.


So if you have an OCS Agnus and fit RAM which require 512 rows refresh then you will have a problem. ECS Agnus generates A8 on refresh I understand.


My board uses CBR refresh (CAS before RAS) to solve the problem, so it works with OCS or ECS the same.


Chris
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Old 11 September 2018, 21:43   #396
Chain
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Found not much of those simm, hope it will be enough for three boards:

can anybody tell which is sutable chip and which not?

Hynix HY5118164B (im sure sobebody on eab uses that)
NEC 4218165-60
SEC KM416C1204AJ-6
SEC KM416C1200AJ-6(7)
LGS GM71C18160BJ6
TI TMS418160DZ


thanks in advance
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Old 11 September 2018, 22:55   #397
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TI TMS418160DZ
Are you sure it's 160? I have used 169 successfully.

Another chip that worked for me is Alliance AS4C1M16E5-60JC.

Making a compatibility list is a good idea!
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Old 12 September 2018, 21:38   #398
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Hm, if i have an A500 with damaged onboard-ram ...is it possible to use this expansion as replacement for the damaged onboard ram if i desolder all amiga onboard ram chips ?

Btw...i've finished soldering 2 ramexpansions fully loaded with ram...all is working nice. Excellent ramexpansion.
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Old 13 September 2018, 19:39   #399
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can anybody tell which is sutable chip and which not?

TI TMS418160DZ

I've built my two expansions exactly with these rams, working excellent

But all of those you've listed should work. If they're not working, something is wrong with soldering or one or more rams you've soldered are damaged rams. Test them in old PC if you can before picking the rams from simm! This way, i've found 2 damaged EDO 72pin simm out of, puh, around 60 tested 72pin EDO simm.
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Old 13 September 2018, 20:46   #400
Chain
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Thanks!
As i have Blizzard card in A1200 i can test it there .)

so we have Five chips confirmed as working:

Hynix HY5118164B
TI TMS418160DZ
TI TMS418169DZ
SEC KM416C1204AJ-6
Alliance AS4C1M16E5-60JC

Last edited by Chain; 16 September 2018 at 23:02.
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