[sebhc] Emulator fix

Steven Parker sp11 at hotmail.com
Sun May 2 05:31:20 CDT 2004

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 an 
output routine.  My mod returns that and TxE together to simulate an empty 

>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 the 
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.

>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 images
>instead of tapes.

That would be really cool.  I might also consider working on that too, once 
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 him 
weeks ago.

- Steven

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