Dropcheck Posted September 9 Author Share Posted September 9 On 9/5/2024 at 8:29 PM, AtariGeezer said: Cool, okay.. Just wanted to make sure you didn't accidentally get +5 and +12 backwards. That would have been a real mess... I looked at Brads site last night and don't see the PAL-A or PAL-B listed anymore. I know I have 4 more PAL-C's (made by @bob1200xl 12 years ago), but will have to locate my 1450XL spare parts box in storage to see if I bought spares of the 2 other PAL Chips. I usually try to buy at least two of most parts for the Atari builds. I also have a spare speech chip in storage too that I was hoping to use in a 2nd build of the 1450xl if any more boards surfaced... Were you able to check on the extra PAL chips? Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 9 Author Share Posted September 9 So have we come to any conclusion about R134? Should it be tied to +5V? Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 10 Share Posted September 10 3 hours ago, Dropcheck said: So have we come to any conclusion about R134? Should it be tied to +5V? I'll be testing that out tonight, will be tying that to +5v since pins 3-4 have a floating high anyway... 8 hours ago, Dropcheck said: Were you able to check on the extra PAL chips? Not yet, still need to pull stuff down from the storage loft to find that box and it's been above 106 degrees outside for the last week. But will get to it as soon as I'm not so over heated... Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 10 Author Share Posted September 10 11 hours ago, AtariGeezer said: I'll be testing that out tonight, will be tying that to +5v since pins 3-4 have a floating high anyway... Not yet, still need to pull stuff down from the storage loft to find that box and it's been above 106 degrees outside for the last week. But will get to it as soon as I'm not so over heated... Sorry, that's right you've still got a little bit of summer there. We've been shivering the last two or three mornings in the 50s. Oklahoma has a bad habit of going to the other extreme one last time before summer really ends though. So we might end up with your heat wave before long. 🙂 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 10 Author Share Posted September 10 Some indication of getting closer to success. I am now getting most chips warming up. I flashed a different ver of the handler rom onto a NEC 2732A. Using the 1450XLHand.ler bin file from the Vandal968 thread and I think from Curt's site. Possibly a bad image or rom before? I changed monitors and display converter to verify it wasn't a display device issue. Getting the same blue to black screen when the 1450XL is powered on. I tested all the custom chips in BackBit's Chip Tester Pro v2. Tested the Freddie replacement chip and it failed, but it was just a lark that it would pass anyway. I have no way of knowing how the cpld would look to the tester anyway. Interesting that the Atari PN is C061922 on the chip and the chip tester lists C061991 only. I know there are two PNs, but Vandal968's BOM lists both with the C061991 installed. Ram is all good. Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 11 Share Posted September 11 16 hours ago, Dropcheck said: Sorry, that's right you've still got a little bit of summer there. We've been shivering the last two or three mornings in the 50s. Oklahoma has a bad habit of going to the other extreme one last time before summer really ends though. So we might end up with your heat wave before long. 🙂 Yep, that's usually marks the end of summer for us, one last blowout of high heat... Last night I ended up spending a few hours outside in the cool air getting some stargazing in. Saw Mars, Jupiter with 4 moons, Uranus and the Pleiades... Tonight I added a wire from R134 to +5v and there wasn't any change in operation of the SC-01. Measured voltage at Pin 3-4 of U8 is now 4.40 volts... Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted September 11 Share Posted September 11 10 hours ago, AtariGeezer said: Yep, that's usually marks the end of summer for us, one last blowout of high heat... Last night I ended up spending a few hours outside in the cool air getting some stargazing in. Saw Mars, Jupiter with 4 moons, Uranus and the Pleiades... Tonight I added a wire from R134 to +5v and there wasn't any change in operation of the SC-01. Measured voltage at Pin 3-4 of U8 is now 4.40 volts... Try it to ground I'm very curious what the real "1400" marked boards show. probably a manufacturing flaw since day one. 1 Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 12 Share Posted September 12 8 hours ago, kheller2 said: Try it to ground Nope, no reason to even try this. Tying to +5v works, tying to ground could lower the floating 1.44v to less than 0.8v which would negate the sync pulse. Remember U8 is a NAND gate, so two inputs of three permanently held LOW instead of a HIGH will result in a HIGH output when we want a LOW, All three inputs to the NAND gate must be HIGH to have a LOW output otherwise you'll get a HIGH output... 1 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted September 12 Share Posted September 12 (edited) So where do those 3 inputs go? are they getting something to synchronize, enable, disable based on a need for an effect that may be required for modem/telephony device or other audio portion for expansion. How about the answering machine function of the machine? Do you have the answering machine cartridge or program? @AtariGeezer Edited September 12 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 12 Share Posted September 12 4 minutes ago, _The Doctor__ said: So where do those 3 inputs go? are they getting something out there to synchronize, enable disable based on a need or effect that is required for some device/audio etc portion or expansion. How about the answering machine with this or that? Can you rephrase that word salad Quote Link to comment Share on other sites More sharing options...
TZJB Posted September 12 Share Posted September 12 On 9/9/2024 at 5:05 PM, DjayBee said: With recent developments this sounds quite ambiguous. 😎 Yep. I obviously can't verify the available FREDDIE replacement chip as I don't have one, but FREDDIE is just an array of logic chips. The replacement should look similar to this:- Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 12 Author Share Posted September 12 (edited) 13 hours ago, AtariGeezer said: Nope, no reason to even try this. Tying to +5v works, tying to ground could lower the floating 1.44v to less than 0.8v which would negate the sync pulse. Remember U8 is a NAND gate, so two inputs of three permanently held LOW instead of a HIGH will result in a HIGH output when we want a LOW, All three inputs to the NAND gate must be HIGH to have a LOW output otherwise you'll get a HIGH output... Okay. So it seems to be reasonably safe to tie R134 to +5v to have a stable high on the two inputs to the U8 NAND gate. One last fix to my prototype board and I'll try another power on test. FYI: No change. I have a ratty 800xl and 130xe coming in Friday. So I'll lift the Freddie chip from the 130XE and have extra OS and Basic chips from the 800XL to check with over the weekend. If that fails to bring up the 1450XL, then it kinda leaves the PALtoGAL converted chips as suspect. Not an absolute guarantee. But ..... Edited September 12 by Dropcheck clarification 3 Quote Link to comment Share on other sites More sharing options...
ivop Posted September 12 Share Posted September 12 22 hours ago, AtariGeezer said: Nope, no reason to even try this. Tying to +5v works, tying to ground could lower the floating 1.44v to less than 0.8v which would negate the sync pulse. Remember U8 is a NAND gate, so two inputs of three permanently held LOW instead of a HIGH will result in a HIGH output when we want a LOW, All three inputs to the NAND gate must be HIGH to have a LOW output otherwise you'll get a HIGH output... This is the correct answer. BITD they quite often used otherwise unused gates to simulate an inverter instead of adding another IC with inverters to the BOM. If the two inputs are floating it sort of works with an NMOS series IC, but it won't work with CMOS. 2 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 16 Author Share Posted September 16 Naturally the USPS can't deliver a package within 300 miles in anything short of four days. Not sure if the 130XE will show up today, USPS claims in transit since yesterday at midnight from less than 100 miles. 800XL did come in Friday via UPS. Seller claimed it powered on, but it's dead as a door nail with two known good ps. Mainly will be robbing custom chips from it anyway. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted September 16 Share Posted September 16 power switch, main filter cap? once you have power to the board, next stop ram Quote Link to comment Share on other sites More sharing options...
+mytek Posted September 16 Share Posted September 16 1 hour ago, Dropcheck said: Naturally the USPS can't deliver a package within 300 miles in anything short of four days. Not sure if the 130XE will show up today, USPS claims in transit since yesterday at midnight from less than 100 miles. 800XL did come in Friday via UPS. Seller claimed it powered on, but it's dead as a door nail with two known good ps. Mainly will be robbing custom chips from it anyway. New system development sure isn't cheap. Well I hope you all the best on getting your creation up and running. When you do, you'll be the first to successfully recreate the 1400XL. Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 17 Share Posted September 17 @Dropcheck One thing I forgot to mention when I was checking U8, is that when removed, it will boot up in self-test mode... Something to try... On that 800XL, sellers often use the term "Powers Up" quite loosely, normally just stating that the LED lights up when turned on... Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 17 Author Share Posted September 17 52 minutes ago, AtariGeezer said: @Dropcheck One thing I forgot to mention when I was checking U8, is that when removed, it will boot up in self-test mode... Something to try... On that 800XL, sellers often use the term "Powers Up" quite loosely, normally just stating that the LED lights up when turned on... Thanks for the tip on U8. I'll try that later tonight. The 800XL doesn't even light the power led. Like I said I'm mainly using it for extra custom chips so I don't have to take down my other Atari's. Of course I'll test the chips so I don't go down that rabbit hole. Just checking if the temp has come down in the attic? 🙂 Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 17 Share Posted September 17 3 hours ago, Dropcheck said: Just checking if the temp has come down in the attic? 🙂 Actually my storage loft is a structure I made 8' x 10' that fits above my bed (picture a super sized bunk bed) and is stuffed to the ceiling full of some of my Atari hoard. So it takes a few hours to go through.. That's what is holding me back right now. Temps are now down to the high 70's. I'm a big procrastinator due to that But I will get to it soon... Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 17 Author Share Posted September 17 12 hours ago, AtariGeezer said: @Dropcheck One thing I forgot to mention when I was checking U8, is that when removed, it will boot up in self-test mode... Something to try... Tried pulling U8. No change. 😔 I did try pulling the Antic chip, which normally gives you a RED screen. Lost all video signal. 😔 I think I have a problem in the display circuit. I've got a logic probe coming in tomorrow. With that I should have a full complement of tools to troubleshoot with. Still uncertain about the PAL chips having the correct programming too. I've already checked the clock signals and power in on the chips. Seems okay. Bridging W2 seemed to make no difference, so since it's related to PAL display I'll leave it open. Still waiting on the 130XE. USPS still has the package listed as in Tulsa less than 100 miles away for the last 48hrs. Thinking about taking a drive to where ever the hell their distribution center is and demanding my freaking 130XE. They'd probably toss me out on my ear though. I hate waiting. 😔 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted September 17 Share Posted September 17 On 9/17/2024 at 5:53 AM, Dropcheck said: Bridging W2 seemed to make no difference, so since it's related to PAL display I'll leave it open. W2 can be left out in all cases, for both PAL and NTSC. To bridge the GTIA PAL colorburst clock input pin to the primary OSC input on an NTSC machine does absolutely nothing. On an NTSC GTIA that pin is a no connect. I suspect that Atari planned on perhaps using it down the road for a possible dual mode GTIA that could switch gears automatically if it detected it was in a PAL vs. NTSC machine. This is pure conjecture on my part, but it would have been nice if something like that had happened. Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 19 Author Share Posted September 19 Finally have the 130XE in hand. Naturally getting no power light when powered on. 😔 This time the seller at least indicated he had not tested the computer. So I'll spend the morning attempting to desolder the Freddie chip and hopefully won't toast it. Then I'll insert it into the 1450XL and see if there's any change. It's a long shot, but I don't know how compatible the Freddie replacement chip is that I'm currently using. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted September 19 Share Posted September 19 1450XL* and ST power supplies can murder x??XL/x??XE's. It's really strange to get multiple Atari's from the random market that don't show a power light. It's not like the power light is controlled by logic chips in the x??XL/x??XE's. Bad LED's and keyboard traces maybe, time to play the lottery numbers using your winning bids and time of day. You might be a winner! Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted September 19 Author Share Posted September 19 As I suspected the problem is not in the Freddie chip. No change. 😔 It appears to be either in the PALs or somehow an error still in the schematics or a solder joint. Okay once more in to the breech. First a microscopic look at all the solder joints. Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted September 20 Share Posted September 20 (edited) 8 hours ago, Dropcheck said: It appears to be either in the PALs or somehow an error still in the schematics or a solder joint. Did I read that you have a loaner built 1450xl correctly? If so, can't you test your PAL's in the loaner? U12 is the MMU, so if that is improperly programmed, that would be a big reason why it's not working... I found a webpage that talks about building an adapter to read the PAL16V8 chip as a 27C020 EPROM in a device programmer. http://dreamjam.co.uk/emuviews/readpal.php Sequence of operations to duplicate a 20 pin protected PAL.pdf Then using a program called Logic Friday to convert the read data into the correct equations. Logic Friday for Windowslf114_setup.exe Not sure if a TL88 can read a protected PAL directly or not... Edited September 20 by AtariGeezer 1 Quote Link to comment Share on other sites More sharing options...
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