[sebhc] H8/H17 emulator available to prelim. trials

Steven Parker sp11 at hotmail.com
Mon May 24 21:57:17 CDT 2004

>I have discovered that if you type like crazy to fill the console
>input buffer until it begins to beep, then hit BACKSPACE a few
>times while it is still beeping, it unlocks, continues with the
>HDOS startup prompt, and everything appears to work normally
>after that...

Boy, you got a wierd one here!   It did exactly the same for me using the 
2.0 distribution disk (maybe thats what you were using).

This isn't sensing behavior - that occurs before the first console I/O.  The 
sensing process is not only to detect baud rate (only on the 8250), but to 
determine which port your console is connected to (it could be either on the 
8251 at 370 or the 8250 at 350).   If an 8250 is present, it would display 
SPACE on the led's and wait for you to hit spaces on your console.  I'm 
guessing you don't currently emulate the 8250 so it went past that to the 
"action?" prompt.

I don't recall ever having any tech inquiries regarding this particular 
hangup on real H8's.  But I do know that the console gets re-initialized at 
that point, because on my real H8 I have to manually turn on RTS then for my 
serial connection to continue talking to it (proper RTS management was 
obviously overlooked in the driver).

So, just a guess at this point .. but take a look at how your emulation 
handles re-initialzation of the chip after it's been in use.  Particularly 
in regard to interrupt handling.


In honor of your achievements so far, I've changed the disk images in the 
archives to all have "h8d" extensions.  :-)  (This also resolves some 
concerns recently expressed about long extensions).


- Steven

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