Adding sram to laser invasion

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nocash
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Joined: Fri Feb 24, 2012 12:09 pm
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Re: Adding sram to laser invasion

Post by nocash » Wed Sep 11, 2019 6:07 am

Thanks, that makes it much clearer to know what have there. The wiring in the drawing looks okay.
I didn't see traces (drawn?) on the photo, but with the new drawing it's easier to understand what is shown on the photo.
mmc5.pin76+75 look misplaced in the drawing (but look okay on the photo, so it should be no problem).
mmc5.pin71 shouldn't be connected as you have only one ram chip.
The diode is gone now?
Though... there are MMC5 photos with SRAM in internet: Those seem to have a diode... between NES.5V and SRAM.VCC?
The resistor is really 1K? if it were 100K then you'd have a problem.
Probably obvious: I hope battery GND is also connected to sram+mmc5 GND.
The battery always has 3V, even when SRAM.VCC is less?

My main guess would be that SRAM VCC,/CE,/WE are accidently shortcut with other pins or with other chips.
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Frankym2612
Posts: 34
Joined: Thu Jun 27, 2019 8:25 pm

Re: Adding sram to laser invasion

Post by Frankym2612 » Wed Sep 11, 2019 9:24 am

Ya I removed the diode it didn’t make a difference. For the pcb I have extra pins because sim city calls for 2 8k ram chips and legend of link needs 1 32k pin 75 are 2 ram ce and 71 which I have on there is fit 1 ram ce. A short does make sense Ille have to keep looking and maybe redesign the board, how I have it drawn is how I have it wired now a little different then the pcb thanks for the help

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