6502.org Forum  Projects  Code  Documents  Tools  Forum
It is currently Sat Nov 23, 2024 1:41 pm

All times are UTC




Post new topic Reply to topic  [ 33 posts ]  Go to page Previous  1, 2, 3
Author Message
PostPosted: Sat Jul 03, 2021 5:59 pm 
Offline

Joined: Wed Jun 23, 2021 8:02 am
Posts: 166
GARTHWILSON wrote:
[color=#000000]On every RAM I've seen, OE\ is irrelevant when WE\ is low. It won't enable the output buffers when WE\ is low.


I had a quick look at a datasheet for a 62256 type RAM and sure enough there it is - the schematic shows a gate which overrides OE if WE is asserted. I never noticed that before. You learn something new every day. It just never occurred to me to have OE and WE asserted at the same time.


Top
 Profile  
Reply with quote  
PostPosted: Sat Jul 03, 2021 7:16 pm 
Offline
User avatar

Joined: Tue Mar 05, 2013 4:31 am
Posts: 1385
Jmstein7 wrote:
I give up. :?


It's not about giving up. Think about what you want to build... in many cases, start with someone else's proven design and go and build it... even this route may have it's challenges, but at least you'll have a solid chance of getting it working. Once you have a working machine, you can start modifying it, adding to it, etc.

You already have a handful of parts... use them. Take your time, don't be so anxious to make a PCB and load it up with parts. Look at the projects page on the forum, look at what other folks have built, and look to understand how the circuit works and why. Some good learning and you'll gain a much better grasp of how to get something working.

And there's a ton of support here as well.

_________________
Regards, KM
https://github.com/floobydust


Top
 Profile  
Reply with quote  
PostPosted: Sat Jul 03, 2021 7:23 pm 
Offline

Joined: Sun May 30, 2021 2:16 am
Posts: 375
BigEd wrote:
I hope this is helpful - and not adding insult to injury!

Indeed, it is helpful. I really didn’t think the jump from breadboard to PCB would be so messy. I’ve breadboarded all of this, but translating bb to silicon is not as smooth as I thought it would be.

First issue I need to solve, one step at a time, is learning how to do my 0.1uF capacitors. Then I can get to the rest. That seems to be the root of my whole “what happened to my VCC?” problem. That is, when I go from schematic to pcb, all my VCCs become GNDs.

Jon


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 33 posts ]  Go to page Previous  1, 2, 3

All times are UTC


Who is online

Users browsing this forum: Google [Bot] and 21 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: