TX16W Hardware Interface

Hardware:

Solder point project board with at least a ground buss. Minimize ground paths and use caps (listed below) at extremes of VCC.
(2) 14 pin sockets, (1) 16 pin socket, (1) 24 pin socket. The circuit should be soldered and the wiring tested before the ICs are inserted to avoid damage.
15-Pin Male D-shell. The RS424 plug into the TX16W.
Three feet of Ethernet Cable. Cable to the TX16W.

Misc: Electronics:

Switching Diode.
10K 1/4watt resistor.
(2) .1 uFd 25V capacitors.

ICs:

UM232R – USB to Serial interface
74HC04 - High Speed CMOS Hex Inverter
CD4040 – CMOS Ripple Counter
74LS74 – LS Flip Flop

The Schematic:

Note on the photo below that the jumper nearest the USB port on the UM232R is in and the other jumper is over pins 2 and 3.

Messy Details:

The interface is just a necessary evil needed to run the software.

I needed to derive a synchronous clock from the UM232R. Because of the speed of the UM232R clock, I used an LS flip flop to get the clock slow enough for the cmos CD4040 ripple counter. The diode and resister are used make sure the derived clock is in proper phase. This is done when the interface is initialized.

There are better ways to do all of this. But these are the parts I had, and it works . (Perhaps there’s a UM232R like device that generators a proper clock. Don’t know.)
BackSide

Also, I know the hex inverter is far from an ideal RS-422 interface chip, but it works. (Note that the hex inverter in the photos of my boards is wired differently than that shown on the schematic.)

Please see other page about the software needed: special TX16W boot disk, the PC disk Emulation software and the various ISO images of the TX16W disks including a modified version of Typhoon.

I CAN’T GUARANTY THAT THIS CIRCUIT or THE SOFTWARE WILL INSTALL or WORK FOR YOU. NOR CAN I SUPPORT THE DESIGN OR THE SOFTWARE.