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About olmstead

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    Space Invader

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    Home Brewing, Motorcycles, Electronics, Programming, and Retro-gaming: especially the Intellivision!
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    GOSUB and Tron Deadly Discs

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  1. Oops...I just realized I forgot to reply, sorry about that! I removed Q2, tested it and it was bad. I have a small 40x magnifying glass and was lucky to read the part number, before seeing your reply, and ordered a few. They came in, I replaced Q2 today and...and...it works now! If this happens again I'm testing theta-1 and theta-2 after the voltage check. <g> Thanks again for the help! It's awesome to have it working again and not just sitting in the corning.
  2. That's what I thoght too! The jw3 line tested out ok. I used the continuity tester to test end to end, then end to U11, pin 2. Beep-Beep! Q2 is a bit harder to test without taking it out, if I understand correctly. So I took some readings and compared it to Q1. Here we go... Just in case, to try and make sure this makes sense: C = collector, B = Base and E = emmiter. It's been ages since I've done this and refreshed here: How to test a transistor Q1 CB + to -: 5.8 Mohm Q1 CB - to +: 1.3 Mohm Q2 CB + to -: 14.3 Mohm Q2 CB - to +: 1.3 Mohm Q1 EB + to -: 1.1 Mohm Q1 EB - to +: -1.1 Mohm Q2 EB + to -: 1.1 Mohm Q2 EB - to +: -1.1 Mohm On the emitter side it just kept dropping... Hmmm....I'd probably have to take Q2 out to know if it's really good, but since the CB readings are so different I'll see about changing it out anyway. Thanks for help!
  3. Well...I replaced the U11 chip and it didn't make a difference. Still nothing out of pin 2. I then swapped the SRAM and still nothing! Since the parts are for the Mattel Intellivision and mine is the Sears Super Video Arcade I've been a bit worried, because the chips all have the same major part number, but another number was different. Then I realized it's probably the manufacture date, eg: 8206 which if I remember right means the 6th week of 1982. Yay! I've been poking around a bit more and am lost now. Do you know what the circuit with the Q1 and Q2 transistors that also uses theta-1 and theta-2 is responsible for? Thanks!
  4. The HD7407P aren't available on Mouser or DigiKey anymore, but I found some NOS on ebay! When double checking the part number on my Intelivision, it's a Sears Supervideo Arcade, I found they used the SN7407N. You can still buy those brand new off mouser.com! Now I wait... I also ordered some 14-pin sockets to make it like the others. Why not? <g>
  5. Before trying the new SRAM I tested the pins as suggested and here's what I've found (you may notice voltages are different than what I posted above. Well, I had left the blue cable from the power supply to the STIC unplugged. Not a good idea. <g>): STIC - pin 10: 1.79 and pin 11: 1.79 CPU - pin 38: 1.79 and pin 37: 0 SRAM - pin 10: 11.4V and pin 8: 0 I looked at the Intellivision main board schematic and found between the STIC and CPU there is the U11 chip and tested it: pin 1 - theta-2 in from STIC: 1.79 pin 2 - theta-2 out: 0 pin 3 - theta-1 in from STIC: 1.79 pin 4 - theta-1 out: 1.79 Hmmm...could this be the cause? I'm thinking that if the SRAM was dead you'd still see theta-2 on pin 2 of U11 and pin 38 of the STIC. But... I looked in the Intellivion manual to see what the chips purpose is and it says that it's a "hex buffer with open-collector high voltage outputs". Would someone explain this? Would shorting it over for a quick test be a horrible idea? Thanks for helping me out!
  6. It looks like I'll be able to see if the sram is the cause! There's one more left if anyone is interested.
  7. After doing some more checking, and playing with the good old auto-config on the oscope, I decided to check the other side of the cpu and sram. On the cpu I got a wave on pin 38 (theta? zero). But nothing on pin 37 (theta? one). Once again, on the sram, I got flat line on pins that had voltage, but around 11 that read 0. So... > 1. Check the 12V jumper line, and the small caps/diodes around the STIC and SRAM. > Eg, STIC locality: C9/CR7 (pin 20), C26 (NP) (pin 14), C11 (pin 40). SRAM locality: C15/CR6, C19 For the STIC: pin 14 is <1V, pin 20 is <1V and pin 40 ~2V. For the SRAM: C9 is ~2V but C15 ~12V. > 2. Check the 2 2N3906 transistors that drive the CPU. I tested the two transistors and they seem fine. This makes me realize I didn't mention the voltages on the cpu and sram. When measured originally, all fell in around ~1.4V to ~2.0V. That's probably not good (aren't they suppose to be a minimum of 5V since that's what comes in?). But, the voltages on the lines coming in from the power supply all measure out where they're suppose to, so something looks to be killing it. I just went back and measured around the capcitors I'd put in, to see if there was a problem there and all seem fine. Then, when rechecking the cpu and stic theta-0 was 5V? grrr... Thanks for reading all this and helping me out.
  8. Well...I didn't get very far testing and I have a question or two... > Does the screen flash when you press reset? I am guessing it does. It doesn't flash during power on, or when I hit the reset button. But this could be for two reasons. I am plugged into an old crt tv, but right now I have it going through a vcr. So, there's just a blue screen until the intv comes on (Well, when I plug a working one in <g>). On top of this, since I replaced the rf modulator I don't know where the channel 3/4 sweet spot is and every time I test it I rotate the video side up and down, slowly, waiting to see if a picture pops up on the screen. >An oscilloscope or logic probe or logic analyzer will confirm if the CPU is pulsing/running, >and the rest of the logic is getting a clock, or if data buses are pulsing. Probing the SRAM will >quickly show if it's working or not. I dusted off my oscilloscope, but I'm having a proble or two. Right now I've just measured the pin-1 side of the stic and cpu, but there seems to be something odd. On the cpu all but pins 3, 4 and 5 show voltage, but it's a flat line, no matter what my time is set to (I had a problem with this because I haven't done it in awhile and I'm not sure what the cpu/board runs at so I don't know if the time on the oscope is set correctly). The sram on the other hand has 10 pins with no power. The pins with power, as with the cpu are all flat as well. So, this could all be normal, bad measurement or something else. I wanted to see what your thoughts were. Thanks!
  9. Thank you so much for this! I'll give this all a try and post the results. It might take me a bit though...
  10. I've been trying to fix a Sears Intv that I've had for about 15 years and I might only have one trick left. So, about 2 years ago I dug it out, plugged it in and B-17 Bomber came on! But only for a few minutes and then the screen went black! After a few resets the screen came back 1/4 to 1/2, but eventually it just stayed black and it's never come back. Since then I've rebuilt the power supply, replaced all the caps on the board, replaced the rf modulator and even swapped out the stic, cpu and the 3 rom chips (grom, srom and prom)! By this point the sram is the only other chip that I could easily swap out, (the Sears version doesn't solder these on!), but I don't have it...yet. Re-searching and reading through the forum I saw that it could be the cause so I'm wondering if anyone has one they'd be willing to sell? Thanks!
  11. It looks like the / at the beginning is missing. Try: jzintv -z3 -f1 Baseball.bin --kbdhackfile=/home/joey/jzintv2016/rom/hackfile.cfg And if that doesn't work, use 'ls' to make sure the path is right. eg: ls /home/joey/jzintv2016/rom/hackfile.cfg For example, on my machine, without and then with the begging /: [email protected]:~/intv> ls home/olmstead/hackfile.txt /bin/ls: cannot access 'home/olmstead/hackfile.txt': No such file or directory [email protected]:~/intv> ls /home/olmstead/hackfile.txt /home/olmstead/hackfile.txt Then you know the path is right and you can copy and paste it into jzintv jzintv -z1 --kbdhackfile=/home/olmstead/hackfile.txt intybasic/samples/controlle I hope that helps!
  12. Thanks for the contest! The last digit for me is 9.
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