[sebhc] Image Transfer program almost there

[Dwight K. Elvey]

Hi All
 I tried my transfer program last night and I got
it to work, mostly. It has a bug but I have a work
around. First, is there anyone that is waiting,
desperately for the image transfer for the H8-5 setup?
If so, I can release what I have tomorrow with
instructions. That way it would be available over
the weekend. If not, I'd like to fix the bug so it
will work without the extra problems.
 This bug was noticed on the H8-4 setup but it didn't
cause any troubles if the sequence I put in the
README.TXT file was followed. It is a funny one.
With the XCON8, if I reset the system before the initial
disk access attempt times out, it exhibits the same
problem. With the PAM8, there is no timeout. I need
to have the H17 attempt a read at the start to get
variables setup and in the case of the XCON8 to
load the H17 code from ROM to RAM. This means that
one starts an access to the disk with no disk in the
drive. For the XCON8 and H89, it times out and then
a reset allows one to run my bootstrap code.
For the PAM8, one has to reset while the drive is
still accessing, because there is no time out.
 Here is what it does. I reset and start my bootstrap
code. When the PC side starts the transfer of the main
code ( I'm not sure how far it gets ), the H8 hangs
with the interrupts turned off. This means no display
and only a reset will recover the front panel. I can
see that the bootstrap received the data from the PC
and transferred control to the main program because
the last instruction in the bootstrap ( a PCHL ) is
overwritten by a NOP ( normal operation ). I put the
PCHL back and restart both the bootstrap and the
PC. This time it works fine. I'm able to transfer
images without issues.
 There is something in the disk system that I need
to be initializing or modifying that gets reset the
first time so that the second time will work. This
same thing is normally reset by the timeout in both
of the H89 and the XCON8. It seems to get reset or
modified by my main code as well before it hangs
because the next time it works fine.
 In any case, I'll be looking into this problem this
weekend. It works now but is messy. If someone needs
it this weekend, I can send what I have now, because
it is useable. I'd need to update the README.TXT.
If it isn't needed right away, I'll work on it and get a
good one available, hopefully by Monday.
 The one currently on the web page works with the
XCON8/H8-4 and the H89 and H/Z90 as is. I suspect
that the new code would work with the XCON8/H8-5
but I've not checked this out yet. I don't think
it has anything to do with the difference between
the 8251 and the 8250 because, under that same conditions
it exhibits the same behavior.
Dwight

 


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