emulatorII-list

WOW, thanks for all that. I'm no techi but think I've got the jist of
it. At least I can identify which pin of IC132 the manual is talking
about now. 

Thanks a lot.   

--- In emulatorII-list@yahoogroups.com, "hoschi1103" <totti@...> wrote:
>
> All following information comes without warranty of any kind. It's
> late and I'm old. Get a second opinion :)
> 
> IC132 is an MC1488, a 4x line driver for TTL to RS232. Pin 10 is the B
> input of the 3rd driver. Cutting it will set DTR (Data Terminal Ready)
> to be always HIGH. DTR is used on both RS232 and RS422 interfaces.
> SD will only connect if it detects the EII as a terminal on the
> serial. (Opposite a modem, which would set DSR (Data Set Ready).)
> I suppose that in early EII OS versions, this line was switched by the
> EII in Macintosh mode but later they left it always on for a less
> troublesome connection.
> Please find a datasheet at
> http://www.klm-tech.com/technicothica/images/14881489.zip
> With the datasheet you can find and measure Pin 8, which should have
> +5V .. +15V immediately after you turn the EII on without a serial
> cable attached. If it is negative, the changes should be done to get
> the serial port working.
> 
> R47 and R48 probably refer to the factory built in RS422 interface, as
> the are not on the original schematics. Perhaps someone can have a
> look in their EII to confirm this. I suppose they are to be changed
> for a higher line voltage on the serial port.
> 
> Finding the correct MAC working with EII can be an adventure. From my
> current work I can see that the timing that EII provides on the serial
> port is beyond anything. It jumps like hell, making it currently
> impossible for me to connect any modern serial interface device to the
> EII. (I'm trying with different RS422-RS232 converters to spy the
> communication). This jumping is from the different length of Z80 code
> blocks used in the EII to handle all kind of in- and output. And they
> do not really use interrupts as one would use them today :(
> So be glad if you can get a tolerant enough MAC that can handle this.
> And never give it away. 
> 
> Greetings,
> Hoschi
>