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

Diagnosing KIM-1 short

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

  • jac_goudsmit
    replied
    Originally posted by gcoville View Post
    This fellow has a very nice scan of the poster. I've spent many hours looking at it.

    http://www.pestingers.net/images/Ant...KIM_POSTER.jpg

    (It was nice to see one of my pictures referenced earlier in this thread.)

    Gilbert
    If you're having trouble downloading the poster, the Wayback Machine has it too.

    https://web.archive.org/web/20071218...KIM_POSTER.jpg

    I also put my own mirror online at http://goudsm.it/KIM_POSTER.jpg

    Be patient: the file is 40MB big!

    ===Jac

    Leave a comment:


  • Dwight Elvey
    replied
    Not meaning to hijack the thread. I usually set the voltage to about 1/3V.
    Once connected it will only be 100 to 200 mv.
    The meter must have a 100 or 200mv range. I use a 5 digit Fluke but it
    is all about getting enough drop to measure a voltage across the trace or board.
    For ground planes I like to use 5 to 10 amperes. This may rerquire soldered
    wires rather than clips, depending on the clips used. These are best at the corners
    of the board.
    Most traces can handle 1 to 2 amperes, even smaller ones. 0.200 volts at 2 amperes,
    across 10 inches of trace is only .04watts per inch. Not enough to worry about.
    Dwight

    Leave a comment:


  • billdeg
    replied
    Originally posted by billdeg View Post
    wow. I did as you said and the KIM sprang to life ... at least now there is something on the display. I did not have pin K on the application connector grounded, I did not think I had to unless I was using the +12v...I was just grounding AA only all this time.

    thanks...now to find a transistor for Q1 so I can read the most significant number of the addresses and test the ROM/RAM. When that's done I will attach to a teletype for input and storage.

    UPDATE: RAM peeks shows ROM in memory matching 6530 listing, yay!

    Bill
    Link to photo of power leads (note this happens to have been taken while attached to my other KIM, a rev G.):

    http://vintagecomputer.net/commodore...ctor-Power.jpg
    Last edited by billdeg; August 27, 2014, 06:23 AM.

    Leave a comment:


  • ldkraemer
    replied
    Dwight,
    Ive got a couple of questions about PS & Meter settings for your method.

    I understand that you first make sure the Power Supply is isolated, no Earth Ground.

    1. What is the voltage setting on LAB Power Supply, along with the ~2 Amp setting for Ground Plane testing?
    2. Is the DMM DC Voltage setting on Auto Ranging or fixed for .000 Range, or does it matter?
    3. If you are working on an Address Line or Data Line Short versus along the Ground plane, is the PS Voltage same as for Ground Plane & current still ~2 Amps?

    I too would love to see a video of how it works.

    Thanks.

    Larry

    Leave a comment:


  • Dwight Elvey
    replied
    I'm try to do that some time.
    I can get my son to be camera man and he
    can plant a short on the board and cover it
    so I can't see it.
    That should make it more official.
    Dwight

    Leave a comment:


  • billdeg
    replied
    I'd love to see a video of that!

    Leave a comment:


  • Dwight Elvey
    replied
    I've used a better method of tracing shorts that even works on ground plains.
    It always confuses people when I try to describe it but it can quickly find a shorted
    part without anything other than some leads, a 4 digit ( prefered 5 digit) DVM and
    a power supply with current limit.
    One places the power supply from one side to the other of, say the ground
    trace and limit the supply to about 2 or 3 amperes. ( yes, on the same trace,
    not through the short ).
    Place one meter lead on the trace that has the short.
    With the other measure along the trace with the current flowing through it.
    When you reach the short, the meter reads 0 volts.
    If the supply has fingers, it may be necessary to move one of the supply
    leads and probe along the finger.
    On ground plains I up the current. You need to first probe one way across
    the board and find the 0 volt line.
    Move the supply leads to the other corner and probe to find another line.
    X marks the spot of the short.
    There are some other tricks like this that I use to find multiple shorts but
    these are easier to show than describe in text.
    Not more easter egging. You'll always know the exact cause of the short.
    The voltage across the trace is so small that I've even used it to locate
    a bad RAM that when soldered down was self selecting when powered up.
    You just have to make sure the supply is isolated.
    Dwight

    Leave a comment:


  • Ragooman
    replied
    Originally posted by Ragooman View Post
    Originally posted by ldkraemer
    In your case, take a look at the LeakSeeker 89: http://eds-inc.com/product/leakseeker-89/

    I know it expensive, but it shows you how it works. I wish I had one to play with, it did get me to thinking about cheaper solutions.
    Hey, that one looks very interesting !
    And it's way cheaper than the I-Prober 520
    It does says it's only for dead-shorts, and not when it's a few ohms.
    But it wouldn't hurt to add this on the bench.

    I found a homebrew fluxgate current probe, similar to the I-Prober 520.
    I'll have to look up the bookmark again. I think it was in the internet archive.
    Found it, here's the link I think this is a great little project
    Might want to back up this webpage in case it disappears.
    http://avrs-at-leipzig.de/dokuwiki/e...ekte/fluxprobe

    Leave a comment:


  • Ragooman
    replied
    Originally posted by billdeg View Post
    wow. I did as you said and the KIM sprang to life ... at least now there is something on the display. I did not have pin K on the application connector grounded, I did not think I had to unless I was using the +12v...I was just grounding AA only all this time.

    thanks...now to find a transistor for Q1 so I can read the most significant number of the addresses and test the ROM/RAM. When that's done I will attach to a teletype for input and storage.

    UPDATE: RAM peeks shows ROM in memory matching 6530 listing, yay!

    Bill
    Glad to hear you got both of them working now
    We might have to get ours all together and make a KIM-1 farm running some code for a display

    Leave a comment:


  • Ragooman
    replied
    Originally posted by gcoville View Post
    You need to ground the DECEN- line which is pin K on the application connector. That will cause U4 D input to be low, and then you'll see activity on K7, K5 and K0.

    oh man, I looked closer at mine again and see that now too.
    It was already wired that way but didn't recognize it.
    I had to look it up online in the KIM-1 User manual - the one book I don't have.
    The wiring is in the Power supply section[see link]
    This is a Address Decode signal for any expansion hardware
    http://users.telenet.be/kim1-6502/6502/usrman.html#F22

    Leave a comment:


  • Ragooman
    replied
    Originally posted by gcoville View Post
    This fellow has a very nice scan of the poster. I've spent many hours looking at it.

    http://www.pestingers.net/images/Ant...KIM_POSTER.jpg

    (It was nice to see one of my pictures referenced earlier in this thread.)

    Gilbert
    I'm having a bugger of a time trying to view that webpage
    I don't have any problems with other websites
    Could it be that 512Kword BGP Routing Table Limit being hit again ?
    Has anyone else tried that link ?
    I checked with the usual "is-my-site-down" services and it says that website is definitely down
    Could someone who has that copy upload it somewhere for us ?

    Leave a comment:


  • billdeg
    replied
    wow. I did as you said and the KIM sprang to life ... at least now there is something on the display. I did not have pin K on the application connector grounded, I did not think I had to unless I was using the +12v...I was just grounding AA only all this time.

    thanks...now to find a transistor for Q1 so I can read the most significant number of the addresses and test the ROM/RAM. When that's done I will attach to a teletype for input and storage.

    UPDATE: RAM peeks shows ROM in memory matching 6530 listing, yay!

    Bill
    Last edited by billdeg; August 26, 2014, 09:23 AM.

    Leave a comment:


  • gcoville
    replied
    You need to ground the DECEN- line which is pin K on the application connector. That will cause U4 D input to be low, and then you'll see activity on K7, K5 and K0.

    Leave a comment:


  • billdeg
    replied
    Working through system..Power on 5V OK but no lights.

    1. Removed shorted zener diode between application and expansion edge connectors. This solved problem with power supply (before pwr supp immediately hissed when power applied). Because my power supply is new and regulated I am told I don't need the zener, temporarily.
    2. Replaced tant cap near 6502, was probably ok but it's a tant so it's a good idea to replace them when they're old just in case
    3. replaced resistor near zener diode
    4. getting pulse at pin 39 of CPU

    At this point, applying power using a new 5V regulated supply returns exactly 5.00 volts in numerous places consistently, so now it's time to work through schematic.

    1. pin 40 of 6502 goes low when RS (reset pressed)
    2. It looks like a consistent wave on pin 39 and 3 on the 6502, but I'd like to see what a "good" one looks like. Mine is a slightly dirty looking wave but I don't expect a perfect sin wave either. I'd call it "probably good"
    3. U16 pins 13, 12, 11 and 10 have a clock. 6502 A0/A1 have pulse
    4. U4 (74145) D = nothing, A,B,C pulse after reset
    5. U4 K0 = high, K5=high, K6=high, K7=high
    6. transistor Q1 legs snapped off (both collector and emitter) need to replace (pnp transistor b>20 , vce>12 - 2n5371). tested base of Q2-Q6 by connecting base to ground with a 1Kohm resistor in the middle - all lit up.
    7. tested 7406 in u17 using TTL tester - reports "passed".

    I found some of these testing tips elsewhere on this site. thanks all.

    Next - test the caps I guess.

    Leave a comment:


  • gcoville
    replied
    This fellow has a very nice scan of the poster. I've spent many hours looking at it.

    http://www.pestingers.net/images/Ant...KIM_POSTER.jpg

    (It was nice to see one of my pictures referenced earlier in this thread.)

    Gilbert

    Leave a comment:

Working...
X