Here you go. This is a good working M100, running properly during test. https://photos.app.goo.gl/pgBErSewdSk6lQ2F3
Click the info button on each pic if the description text doesn't show. That's where I described the actual pins I used and a few other details. Main thing is I interpret "reset out after the buffer" to mean M20 pin 3, in case that's not what you wanted. -- bkw On Tue, Dec 26, 2017 at 7:06 PM, Mauro Pintus <[email protected]> wrote: > Hi, I tried to replicate the measures of Brian end at the following link > you can find my oscilloscope screenshot: > > https://photos.app.goo.gl/n39TcOt24QtVrfJo1 > > The first 16 images are the AD0-AD7 and A8-A15 > As you can see I don't have any stuck condition at the outputs of the > 8085, now i'll verify the buffers and demultiplexers. > Image 17 CLK pin 37 of the 8085 and Image 18 Pin 7 of the 8085 > > The last 6 images are the most interesting. > Here I'm acquiring: > > CH1) ROM CS > CH2) 8085 AD0 > CH3) 8085 IO/M > CH4) 8085 Reset Out (actually after the buffer) > > As you can see as soon as I release the reset button, ROM CS and 8085 AD0 > start moving but IO/M stay low for ~300ms > At this point the ROM CS change completely and from a stady clock, become > like a data line. > AD0 keep changing and IO/M toggle only 5 times. > On the last 3 pictures you can see that this sequence continue exactly the > same over and over every ~300ms > > Brian: Can you please measure this 4 signals in the working unit? > I'm doing a single capture, triggering on the falling edge of the reset > (CH4). > > I hope to be closer to find the culprit :) > > Mauro > > > On Dec 18, 2017, at 6:57 PM, Brian White wrote: > > Ah yeah I forgot to relabel a17. I just went one pin too far and > mis-labeled it. I'm not looking at the pdf now, but the a17 pic will be for > pin 28 whatever that is. > > Thank you I'll look at m21. > -- > bkw > > > On Dec 18, 2017 11:54 AM, "Fugu ME100" <[email protected]> wrote: > > Are BAD M100 A16 & BAD M100 A17 correctly titled on the screenshots? > > The sawtooth will be caused by the multiplex nature of the bus from > AD0-AD7. > > The stuck condition of the lines could just be that the CPU never gets out > of a certain address range so the lines appear never to move. Or it could > be the 80C85 (M19) is indeed bad or the H244 (M21) is possibly bad causing > the inputs to be stuck high. The bad Address lines go straight into M21 > based on the schematic. > > On the bad M100 the pattern repeats ~53ms so that is about 10,000 > instructions (if my math is right) so I would expect all the Address/Data > lines to at least toggle. It looks like M19 is bad. Any other lines > appear to be stuck? > > From: M100 <[email protected]> on behalf of Brian White < > [email protected]> > Reply-To: <[email protected]> > Date: Monday, December 18, 2017 at 5:18 AM > To: <[email protected]> > Subject: Re: [M100] diagnose > > Last night I did a little more poking. > > First, I looked at all the data lines at the cpu on a good M100, and > verified that on a good M100, all of those pins show continuous streams of > data while the machine is on. > > Then on the bad M100 I saw 2 differences from the good M100. > > 1) I can't get a stable trigger lock on any of the A* & AD* pins on the > good M100. > IE, On the good machine the data doesn't repeat exactly around 53ms like > it does on most pins on the bad M100. > > 2) 4 pins are stuck high: A10, A12, A13, A14 > > Screenshots of pins AD0-AD7 & A8-A16 > https://photos.app.goo.gl/vcTg4yUhvjXKBxeh1 > <https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fphotos.app.goo.gl%2FvcTg4yUhvjXKBxeh1&data=02%7C01%7C%7Cb95f328a00c443cac69c08d54619c7f7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636491998893045761&sdata=qHGx%2FKPE7hDkQojuMyGp6OFiuUvW89G5pRICZlOrfdE%3D&reserved=0> > > I thought those ramps and 2-volt sawtooths on the AD0-AD7 lines looked > bad, but the good machine has the same thing. > > -- > bkw > > On Fri, Dec 15, 2017 at 7:52 AM, <[email protected]> wrote: > >> I have a really basic one like this, based on the Cypress CY7C68013A >> https://sigrok.org/wiki/Lcsoft_Mini_Board >> <https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsigrok.org%2Fwiki%2FLcsoft_Mini_Board&data=02%7C01%7C%7Cb95f328a00c443cac69c08d54619c7f7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636491998893045761&sdata=pKKoy6jhKELmp2gu%2FA46lG45dgQ0OEfiZz4kKEBS5dY%3D&reserved=0> >> >> I like to use it with the saleae software, but to have 16ch instead of 8 >> I use Sigrok. >> >> Mauro >> >> >> >> Il 15.12.2017 12:56 Brian White ha scritto: >> >> On Dec 15, 2017 6:16 AM, <[email protected]> wrote: >> >>> >>> BTW: Brian do you have a LA so we can compare the same signals on the >>> ROM and RAM addressing/enabling on the working and not working >>> >> Sorry I am looking at them but hadn't picked one yet. >> -- >> bkw >> >> >> >> >> Con Mobile Open 7 GB a 9 euro/4 sett navighi veloce con 7 GB di Internet >> e hai 200 minuti ed SMS a 12 cent. 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