DC brick wall right supply / Hyperterminal settings

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DC brick wall right supply / Hyperterminal settings

Postby Apple92 » Dec Wed 26, 2007 1:00 pm


I have been running my Replica 1 for two days now. A couple of questions/remarks have come to mind.

1- A the beginning, I used to supply the voltage through a DC brick wall. I then noticed that it is necessary to increase the brick output voltage to about 7.5 volts (insted of 6) in order to get a 4.99 v on the Replica 1 board. My DC brick wall output current is limited to 500 mA. What is the current consumption of the board (with a PS/2 keyboard connected to) under 5 volts ? Indeed, I suspect that the DC brick wall output voltage has to be increased so that the power delivered can reach the lowest input power of the LM7805.

2- My old Apple 2 b/w monitor and my old ps/2 keyboard have gone back to the garage since the hyperterminal enable to use the Replica 1 (I really recommend the USB option). Nevertheless, I noticed that the setting parameter "Character Delay" (10 ms) produces many errors during a text file downloading (some chars are repeated or canceled). When updated to 100 ms, all errors disappear (download is slower of course). Did anyone notice the same thing?

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Joined: Sep Sun 30, 2007 3:03 pm
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Postby Kallikak » Dec Wed 26, 2007 2:18 pm

I'd expect the voltage drop on a 7805 to be around 2V (meaning you should really be putting in 7V+ to get a properly regulated 5V), but my Replica is older than the SE so I don't know the specific part used.

100ms character delay sounds excessive. When not using the ACIA-based serial port, I run quite successfully with 10ms delay. If you are having problems I'd recommend trying 15ms or 20ms rather than going all the way up to 100. :-)

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