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Old 09 July 2018, 18:31   #392
1NOM155
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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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