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cab-dustycloset

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Everything posted by cab-dustycloset

  1. 2600/800 Trackball had two modes Joystick and Trackball. If the game was coded to use trackball movement then it would have variable speed, otherwise it worked like a joystick with fixed speed movement. It was just a little more intuitive to use. I think only Missile Command for 400/800 had the trackball option coded. When playing Arcade games, Trackball games work best using original input devices and not always joystick or buttons as substitute. You need to train the Hand-Eye link to the brain. I've heard that at some competition fight event that a competitor used a steering wheel as his Fight Stick; weird.
  2. Always want to play Centipede, Marble Madness, Missile Command and other Arcade legacy games in the 80's like equipment? I started building an Arcade Spinner from ideas from YouTube, and was able to play Atari Tempest like in the Arcade. I always wondered about a Trackball, if it was possible without going top dollar from Ultimarc or SuzoHapp. I was able to source a 3" Trackball from RetroArcade.us (non P/S 2 model $20-30 cheaper) through Amazon, and revised my code to work with an Android micro-controller. It was a fun little project. If there are any other Adventurous Gamers out there and a little handy with their hands, I have a Github page walking you through the process. https://craigb-spinner.github.io/Arcade-Trackball/ I have various code configurations with 10 Buttons, or stripped down to NO Buttons. Yes, just the Trackball acting like a USB mouse in MAME. (RetroPie or PC) I sourced box parts from a local surplus store and century old wood from my parents basement. Electrical/Electronics from local surplus store, and remaining Electronics store and finally Amazon. The Trackball works great in RetroPie!!! Game On! Craig
  3. Final update: It is working with the 9Vac transformer power pack again. What the heck did I do to achieve this miracle? Well, replaced the power caps - original thought, gone bad with age and insufficient capacity for 5v & 12v regulator to keep up the current. Result -$12 uncertain if this was the issue. Need a $250 Fluke meter, old radio shack stuff didn't always cut the mustard. Then spent hours tracing circuit maybe that SN75451BP is weak or blown (relay is buzzing) - removed from circuit tested on breadboard - lit LED when pulled low - okay I guess, soldered back in and fixed trace with wire wrap (!@#$ - watch out the circuit board looses copper traces easily) When pulled low relay clicks - must be working. Traced the circuit board what/where/how - pin 5 on driver (75451 thingy) goes through a buffer then a tri-buffer then to pin32(P0.7) of the cpu(Intel P8031). Pin5(P1.4) of the cpu outputs to a inverting buffer then to pin1 on the driver (75451 thingy). If either pin1 or pin2 on the driver is pulled low relay is supplied power to close contacts. Hey there is one more 10uF cap next to the cpu - thought originally local power supply to cpu surges - nope. 9.4K Resistor and 10uF cap between Gnd and Vcc with tap between going to pin9(RST) on cpu - when pulled high for 2 clock cycles, cpu is reset. Maybe cap is leaking voltage and forever going into reset - nope. (when using external computer +5v & +12v supply everything runs good) Lets check the output from the regulators they should be fine??? 12v regulator 11.94v - looks good. 5v regulator 3.00v - strange - maybe a short in circuit. Check the rectifier bridge - solder looks suspect - touch them up with new solder. Retest voltages again 11.94v & 3.00v - not good - removing regulator from circuit - tested using output from 12Vdc caps. 3.00v no-load !@#$ bad regulator. new 7805(TO-3 case) -$5.00, new 10uF cap -$1.29, thermal paste -$10.00 (1oz - enough to paint a wall white) new regulator tested outside circuit using 12Vdc caps - 5.01v - good Soldered in new components - 4.94V and 7.4V - What? pulled floppy drive - 4.94V and 11.94V - okay, replug - 4.94V and 11.94V and spin/Track 00. Reassemble drive - front display now acting up. Ooh - ribbon cable looks flacky - !@#$ wire snapped - resolder ribbon cable 2+ hours - removed broker stubs - removed solder from holes, strip/tin (torch insulation - anyone with a better technique to strip of 1/8" of plastic). By-the-way TRAK power touch pad been acting up as well - cleaned silver contacts - test for conductivity - one broken/oxidized lead to nothing - added new push button switch for new power on/off - touch pad 2 of 5 leads good. Option 2 - Silver conducting ink pen $50 (i don't think so) How to test molex power +5v and +12V (the regulators output). Ground pin2 on SN75451BP driver to turn on the relay. If good it should click on and stay on, second grounding should turn off the drive. If the relay is buzzing - hold ground on pin2 to check the regulator output both should be +5v and +12v or very close. Note: Make sure you keep in contact with the gnd on the board - touching the metal cases of the regulators is the same as the gnd What is needed soldering iron 25W or less Thin solder with resin core Sn60Pb40 if it can be found. (get the lead out is causing big problems with electronics today) or rosin/flux solder sucker/solder braid wick small needle nose/large twizzers DMM to test conductivity and voltages and the good capacitance. A good electronic supply shop. good luck
  4. update to Trak AT-D2 drive works with external PC power supply ( molex red +5v, yellow +12v, black gnd - need 1.5A for each as per original regulator max out.) Note: forum http://atariage.com/forums/topic/189988-xf551-psu/ - can use rod's hack; both Trak and XF551 and 1050 use similar power circuits. Remember this process removes the internal power caps and regulator out of the working circuit as you are suppling another power source downstream of the regulator outputs. I found article from germany - walter's hack http://www.b-pahl.de/atari8bit/PC-Netzteil/pc-netzteil.html - run page through google translate to read in english (google toolbar) Looks like PC-AT power supply, there is a comment at the bottom of the page about ATX power suppies. PC-AT(on/off switch) and ATX(always on standby with push button main on) power supplies are different beasts. To use ATX power supply (today's computers) look at http://www.built-to-spec.com/blog/2011/12/20/testing-and-using-an-atx-power-supply-outside-of-a-pc/ Note: For older PC-AT power supply, under power supply - http://en.wikipedia.org/wiki/PC_AT Note: For newer ATX power supply - http://en.wikipedia.org/wiki/Power_supply_unit_%28computer%29 - good read about changes to PC power supplies I tested my TRAK floppy with a ATX power supply still connected to a PC computer as there are minimum loads requirements for a switch-mode PC power supply to have stable output voltages. This test will tell you if your TRAK drive is still working. I replaced the large caps in my TRAK drive - no real change Pin 1 pulled to ground on SN75451BP triggers the relay to close via trak button and held low by the intel processor P8031AH, via SN7407N (thru gate), SN7406N (Not gate), and DM74LS244N (buffer)
  5. I was googling the other day and found this post. I dragged my 600xl(64k) & 130xe out of the closet(15 plus years) last week and was surprise that both worked. Now the floppy drives were another critical-care case. The first drive TRAK AT-D2 plugged in, turned on, spun and displayed the 00 track. Oh where is that SIO cable, dig some more and ah-ha, got it. I sat back down and humm, the drive lights are off. oh well, turn it back on, power cable plug must be oxidized. Plugged in the SIO cable on computer and drive - lights off again. Okay, this does it, my front panel membrane is de-glued from the case, I will pinch between thumb and finger. It will not stay on unless you hold the contacts closed all the time. And like-wise rattlesnake sounds from the power relay in the back. Tried transformer #2 - same problem. l gave up moved onto my XF551. It turns on, looks good, where are thoose disks. Disk 1 - spins - beep - spins stalls - spins again - stalls - ... boot error etc, etc, etc. !@#$. Before I dragged out my old Atari 8-bit machines, i was watching on YouTube about fixing old Commadore computers 2-3 hours fixing old pets, Vic-20s, C64s, etc. and hence the crazy idea to drag out the old Atari's I owned. But during the videoes - power supply issues are common in Commadore machines - aka old Caps - leaks, or dried out electrolyte, or puddling (causing shorts) - Commadore went cheap on overvoltage ceilings eg. 6.3v-9.0v for 5.0v usage. Atari used 16v-35v caps which are more abuse tollerent and as noted in the video gives more life to the device. However, power supplies are another issue. Power caps are big and are not cheap compared to other components. Look on the internet about 70-80s power amps with true 200-300 RMS Watts - Re-capping is common Now what could be wrong with both drives? Power suppy problems? Maybe. Need to bypass the internal power supply +5v & +12v - hey why not piggy back onto a new computers peripherals molax cable. Get one of the peripheral y-splitters or double wire the drive and back to the PCB the +5v, +12v, and Gnd. Turn on the computer check +5Vs between 4.95v-5.05v and +12Vs between 11.90v-12.10v - 1% tolerence. There are many examples on the internet how to use modern day power supplies. You may need to unplug the PCB to get a clean boot of the controller as I was using jumpers and the TRAK was reading out wierd codes. Short to say XP551 still doing its disk spin shuffle but Trak AT-D2 has been loading old games with occasional bad sectors. Amazed that disks are still working after 25 plus years. The power supply in the TRAKs has 3 large Caps +12.1V, +12.4V and 24.6V(voltage doubler curcuit) rated @ 35V 4700Mfd and 1 small cap next to the CPU - 10Mfd @ 6.3v. If the drive works then there is enough guts left in this one. All others are monolithic caps where a hammer or acid bath is the likely demise of these caps - hence likely never will die in your lifetime. 2 large power regulator 7805 & 7812 what I remember the heatsinks used to get hot enough to burn you. They need 3-5v drop across input and output, so, 12v -> (24.6 - 12.0) x 1A = 12.6Watts of heat and 5v -> (12.25 - 5.0) x 1A = 7.25Watts of heat but rated at 1.5A max each. Plus 2 diodes - working and if not then large caps would not all charge to a reasonable voltages. 9Vac x 1.4 (rms calculation of sinusoidal wave shapes) = 12.6v, and diodes drop 0.4v-0.7v explaining the 12ish volts. Plus 1 rectifer bridge - working as previous noted caps. Two/Three options - 1) replace with new PC power supply, 2) replace all large Caps (must find 35V 4700Mfd in proper can size to fit the PCB board and case) assume bad, 3) remove caps and test with Digital Multi-Meter with Capacitor testing feature for high values. (or like-wise test equipment) and replace bad spec caps. Unlike cause regulators cutting out under load due to age? Would need to investigate if ever happens. Or final option recommended by Dragonstomper - pay some one to fix. Good luck on what you try.
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