Thank you so much Brian!!! You got it right also for the reset, yes it is M20 pin3 also on the M10, the schematic is almost identical to the M100 one.
Apparently my M10 is doing the same of your working M100 on the ROM CS and on the AD0, reading the content of the ROM. The big difference I can see is with IO/M. On your unit it moves a lot ~40ms after reset. On my M10 it moves only for 5 pulses every 300ms. Someone have any Idea on the possible cause? I'll continue the investigation and let you know. Hope to get out the LA tomorrow. Mauro Ps: on the shared Google album I've added few pictures of the measuring setup. Inviato da iPhone > Il giorno Dec 28, 2017, alle ore 11:06, Brian White <[email protected]> ha > scritto: > > 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 >>> >>> 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 >>>> >>>> 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. Passa a Tiscali Mobile! >>>> http://tisca.li/OPEN7GBFirma >
