+Stephen Posted July 7, 2012 Share Posted July 7, 2012 Ah - got it. If I am not mistaken, the device he chose was listed as 5V tolerant, but it turned out to not really be. Quote Link to comment Share on other sites More sharing options...
sloopy Posted July 7, 2012 Share Posted July 7, 2012 Yes it is, but there is a different model which works at 5v levels which would not have necessitated the resistors. Namely the XC95144 (not XC95144XL), I am not sure why Candle chose the 3.3V version. The XC95144XL is cheaper, and much easier to find? sloopy. Quote Link to comment Share on other sites More sharing options...
atari8warez Posted July 7, 2012 Share Posted July 7, 2012 (edited) Yes it is, but there is a different model which works at 5v levels which would not have necessitated the resistors. Namely the XC95144 (not XC95144XL), I am not sure why Candle chose the 3.3V version. The XC95144XL is cheaper, and much easier to find? sloopy. I don't get it Sloopy, would you use a 3 volt rated component in a circuit which calls for 5volt components just because 3v one is cheaper. (If you do I am not buying anything from you - lol -) .....He must have had another reason. And actually XC95144 doesn't look too expensive either at $1-3 in quantities of 20 (minimum). http://www.alibaba.c..._10TQG100C.html Edited July 7, 2012 by atari8warez Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted July 7, 2012 Share Posted July 7, 2012 I would guess that the memory chips are 3v only - you have to level-shift somewhere. Bob Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 7, 2012 Share Posted July 7, 2012 Yes it is, but there is a different model which works at 5v levels which would not have necessitated the resistors. Namely the XC95144 (not XC95144XL), I am not sure why Candle chose the 3.3V version. The XC95144XL is cheaper, and much easier to find? sloopy. I don't get it Sloopy, would you use a 3 volt rated component in a circuit which calls for 5volt components just because 3v one is cheaper. (If you do I am not buying anything from you - lol -) .....He must have had another reason. And actually XC95144 doesn't look too expensive either at $1-3 in quantities of 20 (minimum). http://www.alibaba.c..._10TQG100C.html It has already been stated by candle - the chips he used were rated by the manufacturer to be 5V tolerant. It was found out after the fact that they were not, hence the resistors. If a new run of PCBs is done, the fix will be incorporated. Quote Link to comment Share on other sites More sharing options...
candle Posted July 7, 2012 Author Share Posted July 7, 2012 you're mistaken Ray 5V core doesn't mean that it is more 5V tolerant you have core voltage, and io voltage - both are separate 5v core means that device is older and consumes more power - much more power plus, it is obsolete, and i'm not using obsolete components you're also mistaken about tollerance being limited to "short periods of time" - whatever it would mean vbxe for example uses FPGA which is 5V tollerant (and now obsolete) - i its core voltage is 2.5V - again, not 5V - you do belive that you need 5V powered FPGA? i think you'll have to start your own company to make these... anyways, if the device is 5v tollerant, it means it can be used inside system, where there are 5V powered TTL devices (TTL, not CMOS), and Atari is NMOS and all chips have TTL compatible outputs Quote Link to comment Share on other sites More sharing options...
atari8warez Posted July 7, 2012 Share Posted July 7, 2012 (edited) Sorry Candle my major is not electronics, so I may ask stupid questions :-) but thanks for the explanation... So it's Xilinx's fault that we have to install those resistors to prevent damaging the device. By theway, why do they call it "5v tolerant", normally if it's 5v compatible they would jut say it operates at 5v (or maximum to 5volts). Edited July 7, 2012 by atari8warez Quote Link to comment Share on other sites More sharing options...
sloopy Posted July 7, 2012 Share Posted July 7, 2012 Sorry Candle my major is not electronics, so I may ask stupid questions :-) but thanks for the explanation... So it's Xilinx's fault that we have to install those resistors to prevent damaging the device. By theway, why do they call it "5v tolerant", normally if it's 5v compatible they would jut say it operates at 5v (or maximum to 5volts). Because it doesnt 'operate' at 5V, it is just 'tolerant' of a 5v signal being sent to it... and it isnt 5v 'compatible', as it puts out a 3.3v level, which altho most TTL devices will accept as a 'Logic High', it still is not 5V... sloopy. Quote Link to comment Share on other sites More sharing options...
candle Posted July 7, 2012 Author Share Posted July 7, 2012 atari specs says that logic high is at least 2.0V and logic low is 0.8V or below - thus allowing to use 3.3V powered 5V tollerant devices on some occasions, if you take 5V CMOS part, that is not TTL compatible (ie 65c816s running at 5V) it may happend, that it will read from custom chips wrong data, because logic high must be above 2.5V - this is not something that can be observed frequently but possibility exists Quote Link to comment Share on other sites More sharing options...
atari8warez Posted July 9, 2012 Share Posted July 9, 2012 (edited) Ok as embarrassed as I am, I will nevertheless ask this question. In preperation for installation of my U1MB, i proceeded with socketing my 800XL for MMU and OS. I desoldered the chips and I thought I did a pretty good and clean job. Never holding the solder gun for more than a few seconds on each leg of the chips to avoid damaging the chips. With all that care I still managed to lift one trace off of a pad while desoldering the OS. I did not break it just lifted it. I carefully checked for the continuity of that trace and proceeded with the installation of the socket. Did the same for the MMU without lifting or breaking any traces there. I double checked all pins of the socket with my MM to see all are connected properly to their respective pads/traces Before starting the actual U1MB installation I wanted to see that the 800XL is still functioning the same as before with the sockets installed. I inserted the desoldered chips to their sockets and turned the machine ON. To my dismay, all I've seen is a blank black screen. No noises, no sounds, no SIO activity, nothing, just the power on LED is lit but there is no other signs of life. I thought that even with all that care I might have fried one (or both of the chips. So from a spare, dead, for parts only 130XE Mobo, I desoldered the MMU and OS chips and tried the 800XL with those instead of the originals. The exact same thing happened, black screen, no noise, no life. I tried all the combinations of the two sets of OS and MMU with the same results. I re-checked the continuity on that lifted trace and all seems OK. At this point I don't know what may have gone wrong. I didn't try to install the U1MB at all fearing I might brake that too on a mulfunctioning computer. The only other mod on this 800XL is the Chroma mod, where I run a cable with 100ohm resistor from the R57/R58 junction to the DIN connector. I need some suggestions as to what may have gone wrong with this - obviously besides frying the chips - (which I believe would be extremely unlucky of me to have fried all 4 - 2 MMUs and 2 OSes) Ray EDIT: I think I just found a socket leg which is somehow not making contact with a pad even after soldering. So I will re-do that and try again. Edited July 9, 2012 by atari8warez Quote Link to comment Share on other sites More sharing options...
Rybags Posted July 9, 2012 Share Posted July 9, 2012 I'd be checking continuity between MMU and OS sockets to an adjoining point on the board. Chances are it's just a solder joint or 2 that hasn't gone through properly, it only takes 1 fail to potentially cripple the machine. Quote Link to comment Share on other sites More sharing options...
candle Posted July 9, 2012 Author Share Posted July 9, 2012 inspect all these chips/sockets for traces of metalisation being lifted, and if you find any, test continuity on thesse traces on both sides of PCB Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 9, 2012 Share Posted July 9, 2012 Yeah - almost no chance you fried any of the chips. Time to break out the multimeter and start doing continuity checks. I like to do these with the chips in place. Test from the top of the chip, to the bottom of the PCB at both ends of the trace. Takes time, but it's the only way to be certain. BTW - since I do this with chips in place, I never use an analog meter for the continuity tests. Quote Link to comment Share on other sites More sharing options...
atari8warez Posted July 9, 2012 Share Posted July 9, 2012 (edited) Ok, thanks for all the tips guys. The problem was on the pad where OS pin# 16 goes. That pin is also connected to Basic ROM pin#14 and from there goes to many other places like PIA, CPU etc... On the Sam's manual it's been defined as carrying 1v and marked as D4..... Anyway, I was looking one of my photos (I take photos on every step of the way) and suddenly noticed an abnormal looking pad. Surprisingly it was not the pad I lifted during desoldering, somehow it didn't catch my attention until after I examined the photos again. Turns out the upper layer pad was broken at the beginning of the trace and after soldering the socket that socket pin didn't make a connection to the trace. So I decided to run a short cable from OS pin 16 to Basic pin 14 and voila we are back to business again (hopefuly not until the next problem)... Socketing a mobo is one hell of a fun job!!..... Here's a photo of the bad pad and the fix: Edited July 9, 2012 by atari8warez Quote Link to comment Share on other sites More sharing options...
atari8warez Posted July 9, 2012 Share Posted July 9, 2012 Yeah - almost no chance you fried any of the chips. Time to break out the multimeter and start doing continuity checks. I like to do these with the chips in place. Test from the top of the chip, to the bottom of the PCB at both ends of the trace. Takes time, but it's the only way to be certain. BTW - since I do this with chips in place, I never use an analog meter for the continuity tests. My digital MM has a beep tone for continuity testing, very handy as I don't have to look at the MM while doing a test. Quote Link to comment Share on other sites More sharing options...
BillC Posted July 10, 2012 Share Posted July 10, 2012 where are the detailed installation pdf instructions???!! are you selling kits but don't care to post pictures?? There are instructions for some models on Candle's website, below are 2 I know about. 800XL 130XE Quote Link to comment Share on other sites More sharing options...
+orpheuswaking Posted July 10, 2012 Share Posted July 10, 2012 where are the XE gs instructions ???!!! What the hell dude? You sign up today and post in a bunch of threads in a negative manner, maybe temper your tone a bit, there are many people here who can assist with an install, but I have to ask do you even have or intend to buy all of these items you seem to be interested in? Quote Link to comment Share on other sites More sharing options...
candle Posted July 10, 2012 Author Share Posted July 10, 2012 is there any policy on AtariAge towards individuals having 2 accounts - one "main" and the other to troll? 2 Quote Link to comment Share on other sites More sharing options...
Marc Oberhäuser Posted July 10, 2012 Share Posted July 10, 2012 is there any policy on AtariAge towards individuals having 2 accounts - one "main" and the other to troll? There is. Check topic Multiple Accounts here: http://www.atariage.com/forums/topic/54171-forum-guidelines-and-rules/ Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 10, 2012 Share Posted July 10, 2012 Move along - nothing to see here. Just another asshat that has now been banned. Quote Link to comment Share on other sites More sharing options...
Atari8bitCarts Posted July 10, 2012 Share Posted July 10, 2012 where are the detailed installation pdf instructions???!! are you selling kits but don't care to post pictures?? There are instructions for some models on Candle's website, below are 2 I know about. 800XL 130XE Thanx for the link. Is anyone else constructing instructions on lessons learned during install? I see a few posts with good tidbits. In my own interest 800XL. Quote Link to comment Share on other sites More sharing options...
doomguy Posted July 10, 2012 Share Posted July 10, 2012 Received my unit. Thanks Candle! You rock! Quote Link to comment Share on other sites More sharing options...
+Stephen Posted July 10, 2012 Share Posted July 10, 2012 where are the detailed installation pdf instructions???!! are you selling kits but don't care to post pictures?? There are instructions for some models on Candle's website, below are 2 I know about. 800XL 130XE Thanx for the link. Is anyone else constructing instructions on lessons learned during install? I see a few posts with good tidbits. In my own interest 800XL. I unfortunately did not take many pictures when doing my U1MB install, but details for 130XE already exist. However, I have a nice series of pictures for my Incognito install, and will work on getting them, as well as detailed instructions, on my blog here before the full version is released. Quote Link to comment Share on other sites More sharing options...
redman Posted July 10, 2012 Share Posted July 10, 2012 where are the detailed installation pdf instructions???!! are you selling kits but don't care to post pictures?? There are instructions for some models on Candle's website, below are 2 I know about. 800XL 130XE Thanx for the link. Is anyone else constructing instructions on lessons learned during install? I see a few posts with good tidbits. In my own interest 800XL. You would probably sense this when you look at the size of the screws, but on this page http://spiflash.org/block/21.html it says to use a 1/4" drill which is wrong. 3.2 mm is about 1/8" Redman Quote Link to comment Share on other sites More sharing options...
atari8warez Posted July 10, 2012 Share Posted July 10, 2012 So, on a 800XL we have to put away the RF shield don't we?. After the upgrade it doesn't seem to fit anymore.... Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.