Grand_National

How common were these? (these are current photos) RS must have struck a deal probably with the manufacturer since the 1200XLs had trouble selling due to the price. I always thought this was strange because they contained no spec sheet at all (not even voltage or pinouts, let alone a key mapping). The hobbyist back in the day would have needed to decipher this on their own in order to use.

I always thought this was strange because they contained no spec sheet at all (not even voltage or pinouts, let alone a key mapping). The hobbyist back in the day would have needed to decipher this on their own.

I'm not sure exactly what you mean. I meant that out of 3, none worked. I did pay something for these decades ago, but you're right, I won't get top dollar for them since none work 100%. The parts may be worth something, but the goal is to get one (or as many as possible) working, not sell them, at least not yet. Here's a "blast from the past" (see pics). How many of you remember seeing these? -- notice the brand-name they were sold under. Maybe, just maybe, I can get one of these kbds working. If not, then new mylar.

I'd like to ask one more question because I've seen this on several threads. People use the term, "CX-80 acting like a CX-22". My CX-22 has a JS/TB switch just like my CX-80s, so I'd think the functionality of both models would be the same in both modes. What does "acting like a CX-22" really mean? What are the functional differences? or are they referring to the model which doesn't have the switch and I assume only works like a JS?

I've gone over all of the traces again and everything seems fine as well as testing the cable again. In TB mode, with the case apart, by spinning the axles manually, I've determined I can only go down and left. Occasionally, it may jitter to the right or up ever so slightly, but ultimately, the cursor always ends up in the lower left every time. In JS mode, just as the game intro starts, I can briefly go right, but then when the game actually starts, only left and there is no vertical movement at all. Looks like I'll be ordering those chips. The main PCB is held in place by the optical sensor wiring and the TB/JS switch. Once I figure out how to unclip those plastic tabs w/o breaking them, I'll be in business. Thx

Forgive for asking this but the FSM lists a 4019B and I found a HEF4019BP - aren't the first few letters the manufacturer and any trailing letters the packaging type and temperature range? So these would work?

Yes, I've seen those posts about mod'ing them. All of the traces look factory and there are no extra wires or evidence of wires having been soldered on at any point. The one area with "7 traces" looks like a scrape/scratch. I'm fairly certain that the other "parallel scrape of 4 traces" area is a rub from one of the plastic case supports. The PINPOINT soldering looks like a repair but by a soldering tool smaller than any tool I've ever seen. The CX22 FSM is only somewhat helpful. I'm looking for a "symptom / possible cause" section for the CX80 like the CX22 FSM has for it. Dr Venkman suggested a bad logic chip. Are the logic chips a available?

I've checked the continuity of the cable, all of the PCB solder points on the PCB to ground, the TB/JS switch, and made sure no other cable edge connections are grounded. I did notice something strange tho. It would seem as though there was some rubbing or scraping on 2 areas of the PCB over top of traces. One area is where a plastic support sits. These traces seem to have been repaired (with solder). (Some of the scraping is from me trying to determine if the traces were cut, so ignore that.). Sorry, its very hard to get good pics, but the solder "lump" is very obvious using a magnifying glass. To the best of my knowledge, this trakball has never been opened (prior to me the other day). I checked continuity across all of the traces and they all seem good so that's not the erratic behavior of the unit. The solder traces though raise an eyebrow. Anyone ever see this? Also, no one has ever found a CS80 Field Service Manual right, because the PCB is very different from a CS22 Thanks

I dusted off my old Atari 1200XL from college (from 32 years ago) and to my surprise I found 2 others which I must have picked up somewhere along the way. Unfortunately, none work. I've looked through the 1200XL field service manual, but it doesn't seem to help me much. The first one (lets call it, "#1"), gives a diagonal multi-colored moving striped screen. I'm using a home-built composite cable which is known to work. I use it on my 800XL (and the other (2) 1200XLs) without issue (I have another thread about its assembly). The LED lights up when turned on and I can read Atari (probably the scrolling mult-colored Atari logo at boot-up when no cartridge is in the 1200XL. None of the keys seem to work though, not self-test, or even reset. I'm at a loss for what the issue could be. The second and third ones ("#2","#3") have identical keyboard symptoms as above, but the machines seem to boot fine. I get a blue screen with the audio buzz (since no peripherals are connected) and then the scrolling multi-colored Atari logo due to no cartridge. The LEDs are on. The problem is no keys work, not even the function keys or even reset. ALL keys are dead. I can't even do a self-test, b/c I no keys work at startup. I opened one of the keyboards and the mylar looks brand new (no oxidation, peeling, cracking, etc.) and besides the function keys don't work which is separate from the std querty keyboard. I'm at a loss. Any and all feedback is welcome.

I dug through my boxes of Atari stuff which I haven't touched in 32 years. I forgot half of the stuff I had. A regular joystick works with Missile Command. I found a CX22 trakball. A little 3-in-1 oil and its working fine in trakball mode. I found another CX-80. That works fine as well. The first CX-80 though does not. I have virtually no vertical movement and erratic (completely random) horizontal movement. The two PCBs seem to be soldered together, so I can't swap boards to narrow it down. I looked at the schematics (thanks Dr. Venkman), but I'm struggling to narrow it down.

Thanks. The pickups are optical AFAICT. I already have thoroughly cleaned everything and the ball rolls very nicely, but I still have the same result. I guess the next step is to connect it with the Trakball open and move the "optical cut-out" wheels manually to see if the cursor moves and determine if the ball is slipping and not moving the rollers which the optical wheel is attached to. As for the slippage possibility, I'm very doubtful though b/c I can hardly get any vertical movement (when it does move it just goes all the way to the top or bottom w/o any ball movement and also has similarly completely random horizontal movement. I would think that if the ball was slipping intermittently, the cursor would "jump" according to the direction the ball was being rolled, but it doesn't. Seemingly random.

Hi! Since I have the 800XL working again, I thought I'd play one of the classics. I found my old copy of Missile Command (cart - no drives working yet) and found a few Trakballs. I understand Control-T before hitting Start should put the game into 'Trakball mode'. When doing so, the screen flashed and I thought I was ready to go. The Trakball movement was awful. This Trakball was barely used and wasn't really stored in a damp area, but it barely would roll without getting bound up. After reading some posts and a watching a video, I disassembled (this unit never disassembled before) and gave each mechanical (not electrical) moving part a (very small) drop of 3-in-1 oil. The ball rolls freely once again, since there is very little wear on this unit. The problem still is the cursor in the game moves completely erradically. I literally have NO control. I checked the switch on the back of the Trakball and it is in TB mode. I tried JS mode and restarted the game, but I get the same behavior. Its not like only some directions move and other don't. Its completely erratic. Sometimes the cursor will "fly" across the screen and other times it "jumps" in bursts, but usually it gets stuck on one side or the other and never really moves up or down. The fire buttons are fine. I've found a few posts of BASIC programs which supposedly will test the output. I'm not sure what else to look for b/c as I said, this unit is "almost" brand new (based on usage)...bad electronics in the Trakball, bad game port (I tried both), or something with the 800XL? All comments, ideas, etc. are welcome. Thanks

Update: I connected straight lead pins (rather than a cable) directly in the monitor port and connected them to my stereo amp and........... I had sound! So, the question now was, is my TV not accepting the sound signal?!?! (huh?) or something else was going on. Unlikely its the TV since I've used that audio input before and the 800XL should be being anything weird with the sound signal. I had tested each DIN pin separately on the cable to map out the wiring of the cable and I thought I was set. Q: "When is a 5 pin DIN not a fully functional 5 pin DIN"? A: When it comes from a PC keyboard. I saw another post with the same issue I ended up having, but I thought it was an isolated case. The DIN does have 5 pins and 5 wires, but not all pins go to the wires. One of the wires goes to the metal connector case and you guessed it, the pin I needed to make contact for sound with was the pin without the wire. The connector is molded plastic, so I can't really open he connector up to rewire it. I must have touched the casing by accident when I was testing it. But all is not lost. I found the center section to the 5 pin I had from 20+ years ago. I wired that and I now have video and sound out of the monitor port! So, my only really issue left (that I know of, is the power LED being dead). I ran out of time tonight to pop open the case again, but one edge of the kbd connector was pretty oxidized. I believe it was the higher numbered pins. If I'm reading the schematic correctly, the power seems to go in pin 19 & 24 (through a resistor). Does anyone know if pin 24 is for the LED? or maybe the LED is powered some other way? Thanks again, for all of your help.

Dragonstomper, you asked for some pics previously. I think I can post some tonight as the edge socket connector where the mylar is attached is very oxidized. Nothing else seems damaged. I will also do my best to trace and measure the resistors. Thx. Manterola, I will also try the AC mulit-meter testing on the output. Thx. Regarding repairing the mylar Manterola suggested, if the edge is not damaged upon removal, I think I may try your (Dragonstomper) procedure which you posted in 2009. "The oxidized Mylar can be resurrected most of the time by cleaning it with a product called "Goo Gone" (Usually available at your local Dollar store). I have used it to bring several of them back. I just get an old T-Shirt and soak a small part of it with the goo gone. rub it on the oxidized Mylar and leave it for about 5 minutes. then I use a green dish scrubber, put some goo gone on it and scrub the Mylar with it (not too hard just a moderate amount of pressure). this usually takes the oxidation off and Voila! It works. =)"

Could it be the LM358N opamp or would RF audio also not work? I found another thread where audio was low and the opamp fixed it, but the audio low was also the case over RF as well, I believe.