|Re: AME Port Extender|
Message #2 Posted by Tony Duell on 20 Apr 2007, 4:40 a.m.,
in response to message #1 by MikeG
What do you need to know? I have one of these units, no manual, but I traced out the schematic and it's really simple.
A few things to get you started :
It plugs into any port on any HP41. It ignores the select lines on the port.
There are DIP switches at the front to enable/disable slots 1-6 and switches on the side to select which port slots 5 and 6 act like.
The 4 slots labelled 1 2 3 and 4 act like the corresponding ports on the HP41. So you can't have a ROM module in Port 1 of the HP41 and Port 1 of the extender (well, not unless one takes the high half of the page, the other the low half). You could have, say, an HPIL module in port 1 of the HP41 and a ROM module in port 1 of the extender without problems
The 2 slots labelled 5 and 6 can be set using 2 DIP switches each to act like any of the 4 ports on the HP41. Since you can use the front swtiches to enable/disable a particular slot, you could put a ROM module in slot 1, and in slot 5 (set to slot 1) provided only one is enabled at a time.
I forget what slot 7 is. I think it's another Port 4 by default, but you can add a couple of wires inside the extender to make it controllable by the last 2 (normally unused) DIP switches.
You can put a PX28 battery inside the extender to maintain the contents of RAM (HP41C memory modules, extended memory modules) when you unplug the extender from the HP41. There's a toggle switch that turns on an LED when pushed one way if that battery is good. Pushed the other way it checks the HP41's batteries.
Let me know what else you need to know