[sebhc] Emulator fix

Mark Garlanger garlangr at verizon.net
Sun May 2 13:06:36 CDT 2004

Steven writes:

> Mark says:
> >The emulator was first complaining about write attempts to that address.
> It was probably setting up the word size, parity, etc. on the status port.
> >In the read code...both addresses would just return 0.
> The status port should probably always return TxRDY to prevent hanging in
> output routine.  My mod returns that and TxE together to simulate an empty
> buffer.
> >it didn't halt it but it didn't seem to do anything after that.
> I'm guessing this tape software does not support the 4-port serial card
> (with the 8250's), which is apparently how the emulator handles the H19
> connection.  That's what I meant by adding code to support simulation of
> terminal connected on the H8-5 serial port as well.  This particular tape
> software probably won't do anything interesting until that is set up.

Any chance the 8250 is a superset of the 8251 or close enough to
pretend to be a 8250?
It appears the current 8250, for the console, has 8 port (350-357),
since the 8251 only has two address, 372 & 373. Can I create a second
UART object and map the first port to 372 and the second port to 373?
If I remember correctly the first port on the 8250 is the data port and the
second is the status, and that appears to be what 372 and 373 is looking

> >Making the changes you proposed
> >below to the port read code didn't seem to change the end result
> It was only intended to keep the CPU from halting on input attempts from
> other unsimulated ports.
> >I would really like to get the H17 supported, so I can try with disk
> >instead of tapes.
> That would be really cool.  I might also consider working on that too,
> I can do a build.  Looks like Dave Wallace was intending to add that - has
> anyone been in touch with him recently?  He hasn't answered email I sent
> weeks ago.

I just sent him email on Friday, and haven't heard anything yet.

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