If you get the 3 lines of microsoft version info on the tv screen, that does prove the drive is working at least well enough to read the first sector.
When you say nothing happens, let me get this exactly: You get both the "please wait" and the "insert system diskette" prompts. You close the drive door, and shortly after that the tv screen is showing the 4 lines of microsoft and tandy version info. You press reset on the m100. The dvi does not react in any way. The drive doesn't start to run, The tv screen doesn't change. Is that correct? In support of your theory about communication: I just tried on my dvi and I can get all of that exactly the same, without any M100 plugged in at all. Also, I found it doesn't actually seem to matter so much about the order things are turned on. I'm sure the order in the manual is somehow the most certain way, while any other way probably just works by luck and may not be garanteed to work every time. So I would continue to do the manual way normally. But just to run the rxperiment, I just did it totally out of order by turning the dvi on with no m100 even plugged in. Booted the disk in the dvi still with no m100 connected. THEN plugged in an m100. This caused some junk characters to write to the tv screen, which is no surprise because the bus connector is NOT a hot-swap connector! Of course for time mid-way through the act of connecting, some random set of signals are connected and some others are not, and the bus must be a complete train wreck during that second. Then I turned the m100 on and pressed reset and the dvi dos loaded and worked. The junk cleared off the tv screen and going into basic and running dvi commands like screen 1,1 and lfiles worked. The point of all this is to suggest that it's probably not failing for you because it's so fanatically delicate that it only works if you whispered the prayer with just exactly the right level of sincerity to please the fickle gods. It does seem like a cable or other communication problem, given the 2 things I showed here. * You can get all of your observed actions with no M100 connected at all. * You can get a successful boot (at least some times) even if you totally violate the heck out of the procedure in the manual. At the very least, pressing the reset button on the m100 should always produce *some* reaction in the dvi. Even if the dos failed to load cleanly, you at least know the reset press itself was communicated. I suppose it's possible the communication break could be somewhere else besides the cable. There is a tiny bit of pcb traces in the m100 to the bus connector, and there is a small daughter card and ribbon cable in the dvi for the bus connector. But 2 of them having a bad daugher card or ribbon? Does seem unlikely. The only other hint I can suggest is that it IS possible to plug the bus connector on a M100 off-center by one pin, and leave 2 pins hanging off the edge of the connector. It's also possible to plug the m100 side of the cable in backwards since it's not keyed. Do the dvi end of your cables have both a polarity key and a strain relief clip? The polarity key obviously prevents you plugging it in backwards, but the strain relief also ensures you're getting it all the way plugged in, because the latches on the sides couldn't even close all the way unless the plug was all the way in. -- bkw On Feb 17, 2018 12:02 PM, "Randall Kindig" <[email protected]> wrote: > appreciate the thoughts, John. My question is: both drives? That’s why I > bought a second DVI; to see if there was a problem with the first one. > > Also, it seems to me, and I could be totally in left field, that the fact > that it boots to the Microsoft screen off the disk (both of them do this) > would indicate that the drive is able to read the disk. Also, upon reset > of the M100 the disk drive is supposed to light up and read DVI BASIC off > the disk. The drive light for either DVI does not do this. It seems to me > (again, I’m not an expert) that this would indicate a problem with the > communication from the M100 to the DVI. However, I have 2 cables and 2 > M100’s and it doesn’t work with either. > > Randy > > > > On Feb 17, 2018, at 11:50 AM, John R. Hogerhuis <[email protected]> > wrote: > > > > Disk drive broken? Loose belt maybe? Damaged or dirty head? > > > > Is there some way you can test it to gain some confidence? Say, in a pc? > > > > That’s what was wrong with Brian’s DVI in the end. > > > > I think there are some disk drive replacements around. Either you could > buy a new one or find a gadget that uses flash in place of disk. > > > > Floppy drives were maintenance issues back in the day, with old hardware > I’m surprised they ever work at all. > > > > — John. > >
