Forum Rules and Etiquette

Our mission ...

This forum is part of our mission to promote the preservation of vintage computers through education and outreach. (In real life we also run events and have a museum.) We encourage you to join us, participate, share your knowledge, and enjoy.

This forum has been around in this format for over 15 years. These rules and guidelines help us maintain a healthy and active community, and we moderate the forum to keep things on track. Please familiarize yourself with these rules and guidelines.

Rule 1: Remain civil and respectful

There are several hundred people who actively participate here. People come from all different backgrounds and will have different ways of seeing things. You will not agree with everything you read here. Back-and-forth discussions are fine but do not cross the line into rude or disrespectful behavior.

Conduct yourself as you would at any other place where people come together in person to discuss their hobby. If you wouldn't say something to somebody in person, then you probably should not be writing it here.

This should be obvious but, just in case: profanity, threats, slurs against any group (sexual, racial, gender, etc.) will not be tolerated.

Rule 2: Stay close to the original topic being discussed
  • If you are starting a new thread choose a reasonable sub-forum to start your thread. (If you choose incorrectly don't worry, we can fix that.)
  • If you are responding to a thread, stay on topic - the original poster was trying to achieve something. You can always start a new thread instead of potentially "hijacking" an existing thread.

Rule 3: Contribute something meaningful

To put things in engineering terms, we value a high signal to noise ratio. Coming here should not be a waste of time.
  • This is not a chat room. If you are taking less than 30 seconds to make a post then you are probably doing something wrong. A post should be on topic, clear, and contribute something meaningful to the discussion. If people read your posts and feel that their time as been wasted, they will stop reading your posts. Worse yet, they will stop visiting and we'll lose their experience and contributions.
  • Do not bump threads.
  • Do not "necro-post" unless you are following up to a specific person on a specific thread. And even then, that person may have moved on. Just start a new thread for your related topic.
  • Use the Private Message system for posts that are targeted at a specific person.

Rule 4: "PM Sent!" messages (or, how to use the Private Message system)

This forum has a private message feature that we want people to use for messages that are not of general interest to other members.

In short, if you are going to reply to a thread and that reply is targeted to a specific individual and not of interest to anybody else (either now or in the future) then send a private message instead.

Here are some obvious examples of when you should not reply to a thread and use the PM system instead:
  • "PM Sent!": Do not tell the rest of us that you sent a PM ... the forum software will tell the other person that they have a PM waiting.
  • "How much is shipping to ....": This is a very specific and directed question that is not of interest to anybody else.

Why do we have this policy? Sending a "PM Sent!" type message basically wastes everybody else's time by making them having to scroll past a post in a thread that looks to be updated, when the update is not meaningful. And the person you are sending the PM to will be notified by the forum software that they have a message waiting for them. Look up at the top near the right edge where it says 'Notifications' ... if you have a PM waiting, it will tell you there.

Rule 5: Copyright and other legal issues

We are here to discuss vintage computing, so discussing software, books, and other intellectual property that is on-topic is fine. We don't want people using these forums to discuss or enable copyright violations or other things that are against the law; whether you agree with the law or not is irrelevant. Do not use our resources for something that is legally or morally questionable.

Our discussions here generally fall under "fair use." Telling people how to pirate a software title is an example of something that is not allowable here.

Reporting problematic posts

If you see spam, a wildly off-topic post, or something abusive or illegal please report the thread by clicking on the "Report Post" icon. (It looks like an exclamation point in a triangle and it is available under every post.) This send a notification to all of the moderators, so somebody will see it and deal with it.

If you are unsure you may consider sending a private message to a moderator instead.

New user moderation

New users are directly moderated so that we can weed spammers out early. This means that for your first 10 posts you will have some delay before they are seen. We understand this can be disruptive to the flow of conversation and we try to keep up with our new user moderation duties to avoid undue inconvenience. Please do not make duplicate posts, extra posts to bump your post count, or ask the moderators to expedite this process; 10 moderated posts will go by quickly.

New users also have a smaller personal message inbox limit and are rate limited when sending PMs to other users.

Other suggestions
  • Use Google, books, or other definitive sources. There is a lot of information out there.
  • Don't make people guess at what you are trying to say; we are not mind readers. Be clear and concise.
  • Spelling and grammar are not rated, but they do make a post easier to read.
See more
See less

Amstrad PPC512 CMOS Battery replacement

  • Filter
  • Time
  • Show
Clear All
new posts

    Amstrad PPC512 CMOS Battery replacement


    Just acquired a PPC512 for a reasonable price. It's in pretty good nick condisdering, both disk drives work fine, screen looks good (or as good as it ever did), only problem is it complains that the internal battery is dead, and asks to re enter the date and time on each boot if it's disconnected from the mains.

    Could anyone be so kind as to point me in the direction I'd need to look to find the CMOS battery in this? Considering in every other respect it seems to work fine, I don't want to do any unnecessary disassembly on it, if I could just go straight to this battery, that'd be the most desirable option.

    Thanks very much.

    It doesn't have a separate CMOS battery; the clock runs off the same ten C-cells that it uses for power when the mains isn't connected.


      Do you mean C batteries when you say C cells? If so, if it can retain power when it's unplugged, then it should retain its settings.

      Remember, wherever you go, there you are.


        Ah I see, thank you.

        So, seeing as the power switch on it is either battery or mains, when you've got these batteries installed, do you presumably just pull the mains to switch it off when it's on mains? Sounds a silly question I suppose.


          I would assume so. Switching it off using the power switch would turn it off. In laptops, the battery keeps it running when external power is lost. So, when you unplug it, with the switch still on, it should stay running. Unless the battery doesn't hold a charge anymore.

          Remember, wherever you go, there you are.


            Very interesting/unusual computer. I've never seen one before., so I did a search on info. You may already know of the following links:

            Amstrad Users Group:

            PPC512 Technical Manual:

            Link to Service Manual:

            Hope this helps.

            Smithville, NJ


              So, when you unplug it, with the switch still on, it should stay running. Unless the battery doesn't hold a charge anymore.
              Let me explain: The power switch on the PPC has two positions:

              BATT. OFF
              EXT. ON


              BATT. ON
              EXT. OFF

              So if you have the mains plugged in, switching the switch with batteries installed would switch the power source to the batteries, you see what I mean?

              What I'd guess is you just switch to the batteries unplug the mains, then switch back to switch off.


                Oh. Does it turn on when the switch is set to Batt. On, Ext. Off, and it is unplugged from the "mains?" Unplug it first before switching it to battery mode.

                And have you checked if it can remember its CMOS settings for more than 30 minutes after turning it off?

                Remember, wherever you go, there you are.


                  Does it turn on when the switch is set to Batt. On, Ext. Off, and it is unplugged from the "mains?"
                  It does indeed. Out of curiosity, I tried it while it was still on mains, and while plugged in, the switch does nothing. It must have the type of switch that connects the other setting before disconnecting the first. Not even a blip when you switch between power sources.

                  I'll just go down now and try it now it's been off for a while. At least two and a half hours. That should be a decent enough test.


                  Yeah, works great. Even tells you what time and date it was last powered on.

                  So yeah, definitely is the user installed cells that provide the clock memory. Logical, I guess. It's just the power switch arrangement I find odd. It'd make more sense to have perhaps a middle 'off' setting.

                  Just in case anyone may be interested, here is the power button arrangement. clicky clicky

                  So left like it is in that picture, if I were to plug the external mains supply in, it'd just power straight up.


                    Only one problem I could see with the middle "Off" setting is when the user wants to switch it from the external power setting to the battery setting. They would have to turn it off first, loose their work, turn it back on, and resume work. With the current configuration, that doesn't happen.

                    It seems that the battery is in working order. And from what you said, it also retains the CMOS settings.

                    Remember, wherever you go, there you are.


                      Yeah, very true. Never considered that. Yes, all seems well with that machine now. Not bad considering it was sold me with a possibly broken screen and untested. My theory that the screen was disabled, based on a few things I saw on the sale for it turned out to bear fruit. Sometimes it's worth a gamble it would seem.

                      Thanks very much for all your help, everybody.