There is one extra bit of info I can say about the boot disk that I
don't think is probably affecting you in this case becase you are trying
to boot on a 100, but it is something non-obvious and special about the
boot disk, and who knows, everything is a possible clue.
There are both 100-only and 100/200 versions of the disk.
The 100/200 version boots on anything, 100, 102, 200. It's initial boot
sector must have something that first runs something on the computer to
make the computer tell the dvi whether it is a 100 or 200 (similar to
how the TPDD boot does), and then the initial boot code selects between
2 possible next stages.
The disk contains both 100 and 200 versions of all the same utility
programs, including the backup program. Whichever kind of machine you
run on, you can see all the normal files, both .100 and .200 versions.
But there is an undocumented issue that only the Model 200 backup
program creates a fully functional copy of the disk.
If you use a 100/102 to copy the disk, the copy boots and works and
looks fully correct on a 100/102, but fails to boot on a 200.
If you use a 200 to copy the disk, the copy works on everything just
like the original does.
If you only have a 100 you have no way to detect that the copy is bad
because it boots and runs, and the file listing shows all the same files
including the .200 files, and those files are even all good copies.
The difference is only somewhere in the not visible parts in the boot
sector or other initial special boot file, and you can only detect it by
trying to boot the copy on a 200.
Since you're trying to use a 100, I don't suppose this is touching you,
but it's a bug in the boot and/or boot-copying code and you are failing
to boot, so, whatever. idk what you can do with this but it's a thing
that might be somehow related. Maybe the teledisk image is somehow
slightly wrong in a similar way that affects 100 instead of a 200.
--
bkw
On 11/19/24 13:31, Michael Brutman wrote:
(Trimming the message history ...)
So here is my current state:
* The "twist" connector that swapped the bottom row of pins with the top
row of pins was wrong for me, as it was in the other thread. The male
pins should have been straight through - top-to-top and
bottom-to-bottom. I figured this out last night and rewired the twist
connector to correct it, as the other person had done. I've buzzed the
twist connector and everything is there. The IDE cable is new and it is
secure on the DVI.
* My Model 100 adapter (unused so far) seems to also be incorrectly
assembled. I have an email to Gregory about that. (This is in addition
to the incorrect twist adapter.)
* The worst thing that might have happened is the top row was swapped
with the bottom row. Which for the most part is safe, as you (Brian)
note. There are one or two pins I'm worried about that I need to do
more research on.
Both M102s have the same general problem now. I power them on first. I
power on the DVI. The DVI boots, loads from the floppy, and displays
the copyright message. I wait a few seconds, then use the reset button
on the M102. The DVI responds and starts to run the disk drive,
presumably trying to transfer disk BASIC to the M102. This never
completes. No amount of power off-on, reset, or cold start helps it.
The DVI will run the disk light a second or two, pause a second or two,
and then try again. If I press the BREAK button early (maybe Shift
Break?) I can get control again from the keyboard but disk BASIC is not
loaded. If I let the cycle repeat too many times the machine needs a
cold restart.
At this point I have one or more problems:
* The M102s have some damage because I did the same thing to both of
them. I can't tell. Maybe it's time to get the o-scope out and look at
the potentially damaged signal pins to see what they are doing.
* The cable is still wrong, but I think I have it correct this time
after examining everything for myself.
* The DVI might have a fault. Unlikely given its condition and behavior
so far.
* The disk I wrote might be crap. I used Teledisk v2.16 on a 386 PC
with a real floppy controller. It's good enough to load the initial
sectors, but I can't verify the rest of the disk. I might be loading
bad data into the DVI buffers and passing it onto the M102, and that
could be causing the crash. But there is no easy way to prove or
disprove that.
* The M102s have other faults that are unrelated to all of this. (They
have never had their capacitors replaced.)
At this point I'd like to find a working DVI setup in the region so I
can put my M102s on it to see if they are working correctly - I really
want to ensure they weren't damaged with the incorrect cabling. If they
are good then I'm no worse off than I was a few days ago when I started
this project.
-Mike
--
bkw
