[sebhc] Emulator future?

Dave Dunfield dave04a at dunfield.com
Wed May 26 11:13:40 CDT 2004

>>        What changes and enhancements are desired?
>>- Additional disk controllers.
>My top choice would be the "fantasy" controller that reads/writes PC files 
>in a "mounted" folder.

I'm still waiting on your answer on HDOS's ability to support a network (ie
foreign) file system. Without this ability, what you are requesting is very
difficult (you have to present a valid filesystem to HDOS, meaning you have
to "lay out" the PC files into a virtual disk, and maintain translation back
and forth - ugh!)

>Two optional configurations (both support 0-org memory and dynamic rom 

>The ability to have an HA-8-8 extended configuration "board" (with 
>associated mods).

What does this do?

>The ability to have an HA-8-6 (z80) CPU board.

Perhaps someday - thats a major change, mostly to the debugger.

>Also,  think I found another bug .. with the /I option, I was expecting it 
>to act like a real H8.  But when I tried the H17-rom memory test, 
>(pc=030.003, hit go twice) it threw me into the debugger when it encountered 
>the HLT rather than just returning to panel monitor mode and waiting on the 
>2nd press of "go".  And... it was not possible to continue by hitting 
>'enter', since the monitor never got a chance to advance the PC.  Actually, 
>perhaps it should not even require /I for this to work right.. as "hlt" is a 
>defined opcode.

This has nothing to do with /I - the emulators response to the virtual CPU
executing HLT is to trap to the debugger. If you want to proceed with the
next instruction after the HLT, you can manually increment the PC with the
register editor and then hit ENTER (run).

I'm not sure how this is supposed to work - normally, if you HLT an 8080 with
interrupts disabled, it never starts again (short of a reset). If you HLT it
with interrupts enabled, it will wake up to service the interrupt and then
proceed on it's merry way (still in the application). So as far as I can see,
executing HLT would simply wait for the next clock interrupt and then proceed
"where it is" --- how does it get back to PAM-8?


dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Vintage computing equipment collector.

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