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kenzre

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Posts posted by kenzre

  3. Posted · Edited by kenzre
    left out info

    The problem seem to be in either the on board ROM or the Custom I/O chip. There is a SLIGHT chanch that it could be one of the other2 customs chips.

    Ken Lill

    P.S. There is even a slighter chance that any of the following capacitors is bad: C24, C31, C38 or C45. R31 may be bad. Also one of these diodes: CR9. CR14, CR19 or CR24. I have listed the type of parts on this P>S> in the order I think they may go bad and cause this problem.

  4. Posted

    The 8 DRAM chips are clustered on the PCB. Using the Service manual they are U24-U31 inclusive. Your particular problem appears to be an address issue. Because they are all in the same row, It may be that one address line is causing this problem. Without a logic analyzer or oscilloscope, it would be next to impossible to figure out exactly which is bad, the address line or the data bits in the RAM. They only way to fix this other than with test equipment would be to replace each DRAM one at a time to see if that fixes the problem. However, do NOT mix the '64's with the original DRAMS. they have only one power connection and it is on a different pin. Please refer to the DRAM datasheets.

    Ken Lill

  6. Posted

     

    It was Steven J Tucker who designed the 256K (later upgraded to 512K) Astrocade bank-switch flashcart The board was just a plain PCB and was never sold. When Michael (who was working with Steven) sent me one of these for testing, I provided my own cartridge shell and hacked-it-up (quite literally using a hack saw!) so that the PCB would fit in it. One side of the PCB plugged into the Astrocade and the other side plugged into the Atari Max Flash cartridge programmer. This cartridge worked great, but it never went into production, nor was it ever available for sale. Here are some pictures of that board:

     

    attachicon.gif256K_Astrocade_Flash_Cart_01.jpg

    attachicon.gif256K_Astrocade_Flash_Cart_02.jpg

    attachicon.gif256K_Astrocade_Flash_Cart_03.jpg

    attachicon.gifFlashCart PCB Card Orientation.jpg

     

    The Atari versions of this flashcart are still available for sale here:

     

    https://atarimax.com/

     

    I look forward to trying out this new Astrocade flashcart; it looks very useful. If I had one, then it would allow me to test hacks of Astrocade games so much easier on real hardware. Gone will be the days of EPROM burning!

     

    Adam

    my own personal opinion: I would have tried a 90 degree connector on the Bally end so that the plug could have come out of the top, kinda like the UltiMulti switch. mIt doesn't have to be an edge connector, it could be pins.

    Ken

  7. Posted

    You kind of read my mind with that 3D-printed case link! It never occurred to me to check Thingiverse for an existing model... how cool! I love the pink and white shell combo, too.

     

    In case anyones curious, I cut the hole in the Astrocade cart with a regular old X-Acto knife. I was originally going to use it just to score the cart before going in with a Dremel, but the plastic was so soft that I decided to give it a few passes with the X-Acto. It worked great, and the cuts ended up being much straighter than what I could have done freehand with a Dremel. (It was a little sad to deface a real cartridge, but I think it was OK to do one in the name of science.)

     

    I looked a bit at other flashcarts but havent investigated compatibility between those and the Astrocart yet.

    You might want to get in touch with Michael DeSalvo on ballyalleycom to see what he and someone else did for a 256K cart. It might help you.

  8. Posted

    Do not have a date for finished product, still some mods and debuging to do. On the 3 board rev. Maybe one or two more. Here are some more pics. Anyone well versed with bally machine language let me know if available later to help with menu system. Right now menu is on lcd on board. Later if we can create an easily installed highres option we will need on screen menus. Need is a strong word, lcd is very nice, on screen menu would be more finished. My son and I both work, so this is a side project. I want to finish it though.

    I see a LOT of over-kill with heat sinks. If the ADDRESS and I/O chips aer getting hot enough to apply thos heat sinks, there is something wrong with your unit, as well as the HS on the OSCILLATOR. When one of the address or I/O chips fail and you have to remove them to check, How will you know which one is which? Plugging them into the wrong socket can be dangerous because the power supplies are on different pins..

    What type of Hantek unit is that? I have never seen it before.

  10. Posted

    There is only one program different on 3.2. It is the Color BASIC program that is able to save your BASIC program that you've created. You must have the original Bally 300 baud cassette interface to save and retrieve the info. It will cost you $25.00 for either upgrade. Is it worth it to you just for that program?

    Please, let me know..

  11. Posted

    There are several things that can cause your problem:

    First of all.. note if the artifacts as always coming up on the same places on the screen. If so, you probably have a bad DRAM chip or 2.

    If not, then it could be the custom DATA chip, U23 (The read buffer for the DRAM), or your Z-80 microprocessor., probably in that order.

    Try blowing a fan over the unit when you remove the top.

    Putting heat sinks on the custom ADDRESS and I/O chips really wasn't necessary as they really don't get warm enough to damage themselves unless they are already bad. It also makes it harder to know which chip is which.

    If the fan helps, you probably have a custom DATA chip that is on it's way out.

    Putting a laptop cooler underneath may lengthen the life of the unit.

    Ken Lill

  13. Posted

    Have you had any luck finding the solutions to your problems? I don't get up here much, so that is why I haven't responded prior to this.

    If you have a volt-ohm meter, the 1st thing you want to check is the voltages. There are 4 different values to look for:

     

    10V ( this is power to all custom chips, the last stage of the Oscillator and the RF modulator.) Ground to pin 40 of the custom address chip. (the middle one.)

    5V any small chip, usually the highest number pin (I.E. pin 16 of a 16 pin chip.) to ground. 4.5 to 5.5V. Iv lower than 5V, you probably have a shorted part somewhere on the board

    -5V This goes to the modulator and to pin #1 of the RAM chips, located under the keypad.

    the last supply can be either 15V or 12 V. It goes to pin 8 of the RAM chips...only. To know which one you have, look in front of the silver colored, finned heat sink. If there is a jumper there, you have a 15V unit. If it is a 1/2W 47ohm (Violet, Yellow, Black, Gold) resister it is a 12V unit.

     

    If any of these are more that 15% off, that is the area to check. You'll find the schematic on ballyalley.com in the service manual last 3 pages.

    Ken Lill

    • Like 1

  14. Posted

    The 7.5VAC (which is actually low, it S/B around 8.3) is ONLY going to the +5VDC circuit.

    As far as regulators, the 78 / 79 series are direct replacements for the LM324 regulators.

    There are 2 reasons for the "different" way of doing the +5v circuit the way they did originally:

    1) the Pass Transistor configuration was the best way to acquire a high current. The new regulators can go as high as 3.0A with the proper heat sink.

    2) the switch they used was only a DPST configuration. So by controlling a regulator that drove the pass transistor, they could shut off the +5V supply to the PCB. This design is very poor

    because : A) the bridge diodes are still conducting and

    B) the 10,000uFd Lytic is still across them. I had one of those 10K caps blow out on me with the switch off. I was glad I was right there so it couldn't start a fire.

     

    If you have a scope or a frequency counter capable of handling a 10V P-P signal, check pins 9 & 10 on the custom data (under the keypad) to should get a clock signal approx 7Mhz ( double color burst) and @ pin 16 you should get approx 3.5 MHz clock. If you don't get the signal @ pins 9 & 10, the culprit may be the 74S74 under the Kludge board. I have found that goes bad on occasion. If the signal is there, then check pin 40. (DATEN) if you get nothing there, NOW the trouble comes. Almost anything on the PCB can cause that signal to not appear. Ask me how I know THAT!

  15. Posted

    I STILL HAVE SONE STOCK of Lil' WHITE RAMs and UltiMulti carts ($125.00 USD each + P&H of $15.00 per order). I also have some composite Video boards that require some soldering (3 wires) $50.00 Free shipping. The video boards have NO shadowing and also have pseudo stereo (both sides have same output) Most modern TV's have the 3 connector arrangement (Yellow - Video, Red - Right side audio, and White - Left side audio).

    At the end of this year (2017), I am planning to retire from manufacturing these products.

    Ken Lill

    GaMBITS Engineering

  16. Posted · Edited by kenzre

    This unit is only slightly modified. I replaces the 10KuF lytic and moved it to where it wants to be electrically, nearer The diodes. Every chip socketed. The keypad PCB is missing. the rest looks the same as any Astrocade unit and the late Bally units.If you check the documentation on the Kludge board in the Arcadian newsletter, you will see that it also has most of the changes discussed. Also the power switch is missing the top/contacts.

  17. Posted

    The order of testing s/b

    1 pulling the custom chips

    clipping the 10K uF

    " " 1500 "

    clipping any HOT parts.

    The custom DATA (under the keypad) normally gets real hot as does Q1 and the +10V regulator. The +12V gets warm but not hot. The 2 watt resistor at the front of the PCB gets hot also. It is on the +10V line. The custom address chip may get warm but never HOT. and the custom I/O (closest to the hand control ports) usually runs pretty cool.

    Try to clip parts so that a little solder will put it back in the circuit if it it not the culprit.

    Clip bypass caps, the chips. If you just clip VCC or GND pins on a chip, the rest of the chip could be shorted, so removal is usually the best deal.

     

    REMEMBER these PC boards are over 30 years old and the glue uded to attach the copper may be dried out and will lift if too much heat is applied.

  18. Posted

    OK,let's start from the top. The 4 2K On-Board Rom chips were replaced by one 8K ROM when the cost was more feasible. Easier to assemble, less parts to go wrong. The bypass caps c88,94,&94 were no longer needed because the chips weren't there. The capacitors C55,56,61 were found to be unnecessary as the chips could handle the small spikes in the signals. The same goes for c58-60. The resistor near Q1 was for the change from +15V to +12V on the DRAM chips. These were more common when all of these changes came about. The +15V DRAMS were no longer made. As like other "wave shaping" capacitors, it was found that they really weren't needed. The digital chips were being made more "bullet proof". Getting to the 2 screws under the shield is common.

     

    Now, about your voltage problem. try clipping the + side of the 10KuF cap, attach your meter to the pins on the light pen connector on opposite sides. Don't touch the center one and either side. To do so may fry your custom I/O chip. You should see + or - 5V depending on which lead is on which pin. The one closest to the hand control port #3 is the +5V, the other is ground.

    turn the power on MOMENTARILY. If you voltage doesn't come up, try the 1500uF after resoldering the 10KuF. If you don't see any significant change, you probably have a short on the PCB. Maybe an IC or a bypass capacitor are usually the culprit. I found one bad cap by accident once. I was feeling around for a hot chip when I felt a hot part. It was a bypass cap. I cut it loose, and things were OK. There have been times that I had cut every bypass out, and started pulling chips until I found the culprit. I replaced most of the chips I pulled with CMOS equivalent. They work find.

     

    Another tip, pull the custom chips (the 3 40 pin socketed chips) one at a time to see if one of them is bad. They use +10V and +5V. If one of them is shorted, that will bring down all of your supplies. Last, but not least, check the 3 diode bridges. If one of the diodes is shorted, you'll be introducing AC onto the DC lines, lowering their voltage.

     

    If you have any more problems write me back. We can do this!

  20. Posted

    As of 1/1/17

     

     

    I have 1 more UltiMulti Version 2.5B left for sale already made and ready to ship.

    I also have 1 Lil' WHITE RAM 32K expansion unit for sale. (There are 46 programs of the 163 on the UltiMulti V2.5B that require some form of extended memory)

     

    Both are new, and I can ship within 2 business days.

     

    If any more are wanted, I will require 50% down ( I will need to order PC boards) and it will take 2-4 weeks to get parts, assemble, test and ship.

     

    I did say the price is going up..

     

    They are each $125.00 + $15.00 P&H

    If both are ordered, one P&H fee will be dropped.

     

    Ken Lill

     

    GaMBITS

     

    P.S. I will be discontinuing manufacture of any new products by year's end due to health problems.

  21. Posted

    IF you can solder, I make a comp video / pseudo stereo (both sides actually have identical outputs) board that requires soldering. The cabling is larger than the standard RF cord, so it would either be a tight fit or you might need to file the Arcade a little. The other 2 ways id can be installed is either a 3 RCA jack unit ( yellow,red,white) made for mounting to the unit, but that would require drilling 5 holes, 3 for the jacks and 2 for mounting, OR I can send it with a 35mm jack and special cable that goes from the 35mm to the 3 RCA cable.

     

    The PCB, fully assembled and tested with the 3 RCA in one is $50.00. comes with mounting instructions, wiring to go to the unit and jack.

    The 35mm jack version is $75.00 because it has the extra cable.

    A 6 foot 3 wire RCA AV cable (YRW connectors both sides) can be used by either... $15.00

    Shipping, Processing and handling fee of $15.00 required if shipped in US.

     

    Requires that the modulator box has to be placed back on it's jack to get a color output. Without it, you will get a B/W output.

  22. Posted

    Thank you so much for letting me know about eBay's Global Shipping Program. I had not heard of it before now. After doing research, I have agreed to use this feature. Please retry to see how much it saves you. Please let me know the amount so I can pass it on to others that are international buyers.

  23. Posted

    Version 2.50 is identical to 2.00 except the physical make up is changed and 1 small program is added that will only be useful to people that have more than one unit. It is not worth the extra money unless you are a collector looking to acquire one of everything. That being said, if you have a version before 2.0, WAR & CRAZY CLIMBER ( which both sold for $50.00USD) are the main add ons as well as the original Blue RAM Utility Version 3. The programs that need to switch between program and AstroBASIC have been made easier to understand, and some were made into BASICcarts.

     

    Starship UK: Please purchase through eBay as it will calculate the necessary postage. You will be responsible for all fees and tariffs associated upon its arrival into the UK.

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