Announcement

Collapse

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

Found a method of upgrading Macintosh 128k memory!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Found a method of upgrading Macintosh 128k memory!

    It's probably already known by now, but I just discovered this yesterday:

    https://macgui.com/news/article.php?t=466

    I'm already working on it.

    But, there is good news. I have preserved the original Apple-branded 128k chips, with one heat-gun treatment. (Hey, I'm not that cheap. I'm not going to clip and throw these away.)

    I already have cleared one row, and I think I have most of the components that I need. The last one is coming tomorrow. (A multiplexer.)

    At least this gives me a reason to use more of the good 256-kilobit memory chips that I got for my Sanyo's memory upgrade project.

    #2
    I think the ultimate thing to do would be to obtain a 512k board to pop in there, that way you could just store the 128k board away without disturbing it. I was thinking about doing that when I was looking at a 128, but ended finding a nice 512 instead, which actually turned out to be a dealer upgraded 128, which I think is awesome.
    Compaq - It simply works better

    Comment


      #3
      Back in the day, my 128K Mac was upgraded in a dark room of a back office behind a non-descript door in a Pasadena alley. Opportunistic, guerrilla work to be sure.

      Comment


        #4
        Congratulations for actually doing the right thing to a 128K Macintosh.

        (Although, yeah, you may regret it financially because there do seem to be a lot of bozos out there so obsessed with the idea of having an original, "virginal" 128K Mac, despite the fact that they're utterly useless, that you may have been able to swap your board to one of them for their already period-modified board plus significant cash on top.)
        My Retro-computing YouTube Channel (updates... eventually?): Paleozoic PCs Also: Blogspot

        Comment


          #5
          Originally posted by Eudimorphodon View Post
          an original, "virginal" 128K Mac, despite the fact that they're utterly useless
          I'm working on writing an email client, FTP, and Telnet that will work on the Mac 128K. A web browser and Usenet newsreader are also on the to-do list.
          Mac 512K Blog

          Comment


            #6
            Originally posted by DFinnigan View Post
            I'm working on writing an email client, FTP, and Telnet that will work on the Mac 128K. A web browser and Usenet newsreader are also on the to-do list.
            What are you using for a TCP stack? How are you networking the Mac?

            The web browser will be a challenge, everything else should be straightforward. TCP is simply expensive memorywise.

            Comment


              #7
              Welp, I was wrong. I DON'T have ANY of the passive components I need (except for the logic IC). I'll have to worry about that later.

              Anyways, yeah. I got tired of having to worry about "Not Enough Memory!" when I started games like "A Mind Forever Voyaging"...

              Also, I had plans, anyways, so I could use up the 256Kbit memory chips that I have.
              Last edited by T-Squared; October 30, 2021, 09:23 PM.

              Comment


                #8
                Ok, I got them. (Plus a replacement click switch for the mouse. The one I have seems very weak. Not enough tactile feeling.) Also, I'm close to completing this. One of the older frames I had from before fit perfectly. I mean that as in, the floppy drive was on the proper level, and didn't need anything to level it off. (One of the other frames I had prevented me from pushing in a floppy disk because it was ever-so-misaligned.) Although, it took some work to restore that frame, because it was mostly rusty, and wouldn't look good or be good for the motherboard inside.

                Comment


                  #9
                  Originally posted by Eudimorphodon View Post
                  Congratulations for actually doing the right thing to a 128K Macintosh.

                  (Although, yeah, you may regret it financially because there do seem to be a lot of bozos out there so obsessed with the idea of having an original, "virginal" 128K Mac, despite the fact that they're utterly useless, that you may have been able to swap your board to one of them for their already period-modified board plus significant cash on top.)
                  The thing is, I don’t think most collectors are buying a 128 to actually use it, more for historical value. Kinda like the Apple 1, I don’t think those are terribly useful either. A completely untouched base model IBM 5150 REV A from 1981 would be quite useless too, but undeniably cool.

                  But yes, if you want to use your Mac (like me), you want that 512k.
                  Compaq - It simply works better

                  Comment


                    #10
                    Ok, got everything installed. Now I have a problem. Some memory seems to be bad. I get a short burst of static where the startup bell tone should be, and the image on the screen shows what would be a Sad Mac, except very chopped up and with random, but patterned garbage. I can see numbers (I know its the error code), but even that is very scrambled, and I can't even get a full number (Maybe a few zeroes, an F here and there, etc.)

                    Comment


                      #11
                      Ok, I did try the 256-kilobit memory I had intended for my Sanyo MBC-775, but that seemed to be borked too. I have more chips on the way.

                      I'm guessing the system is working correctly if it at least displays an image (or attempts to), right?

                      The Sad Mac image and numbers are broken up (assuming because of the memory being bad), but the system turns on, and forms an image on the screen.

                      Comment


                        #12
                        Well, I found one reason. I'm not getting continuity of Pin 6 or Pin 10 of any of the sockets. As in, there is no continuity on ANY pin 6 or pin 10 in the RAM array. I don't know what that signifies. I get continuity on the rest, though.

                        Comment


                          #13
                          Never mind. I was reading it upside down. I was getting the appropriate continuity.

                          Comment


                            #14
                            Okay, I bought some memory from Unicorn Electronics, but I keep getting an extremely-corrupted Sad Mac (with some pieces of the picture being repeated horizontally and vertically) and a staticky buzz every time I turn it on, instead of the bell tone it's supposed to produce on startup. The error code is also unreadable, but I'm guessing that this is no ordinary code, because the one letter "F" that I can read doesn't look like it's supposed to be there in relation to the Sad Mac icon. Like "000F0000". The rest is garbage or repeated segments.

                            My hunch is that a logic chip has failed, because it doesn't work even with multiple brands of chips. I have tested for appropriate continuity, though; memory-to-CPU and memory-to-memory. They seem fine.
                            Last edited by T-Squared; November 19, 2021, 03:56 PM.

                            Comment

                            Working...
                            X