Hi, I think that this looks correct, please confirm. I am ONLY showing my connection to the 62256 32k x 8 ram CE pin that I added to the web page picture, slide 15: When A13,A14,A15 are all low, the 2764 should be selected. When A15 is high, the 62256 should be selected.



Keiichicom

 

hi keii,
Why not a 3 Input OR gate for 2764 Select decode.?
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Why not a 74LS138 to include all the other devices that you need to address?

 

hi keii,
Why not a 3 Input OR gate for 2764 Select decode.?
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Actually I can't, because I need the inverter for the 62256.

 

Why not a 74LS138 to include all the other devices that you need to address?

Eventually i will be doing that, I just wanted to do something quick here, to test a small program in ROM.

 

Hi k,
Like this
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Hi k,
Like this
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View attachment 289051

Ok, thanks that works.

 

hi k,
I see that you are using a 32K byte RAM. ie: A0 thru A14 address lines, so why the decode on A13/A14.

Use A15 as ROM / RAM select.
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Edit: do you have a complete circuit diagram to post, we can then give more defined help.?

 

Yes, that should work. There are no conflicts.