smartportsd-nano-shield

Hardware Component Choices and Assembly

Interactive Bill of Materials (BOM)

Connecting to your Apple II

You have two options here. If you are lucky enough to have a DB19 to DB25 DuoDisk Drive cable, you can simply solder on a female DB25 jack and you’re good to go.

Or you can wire up your own cable using the 2.54mm 9p header J2. The pinout is as follows:

SmartPort DB19 pin J2 pin
RDDATA 18 1
PH0 11 2
PH1 12 3
PH2 13 4
PH3 14 5
WRDATA 19 6
+5V 6 7
GND 1 8
WRPROT 10 9

Arduino Nano v3.0

I’ve have good luck with the ~$2 Chinese clones, but I would suggest flashing it first before soldering to the board. Sometimes you do get a bad unit, or a unit that hasn’t been flashed with the boot loader and requires you flash it yourself via the ICSP headers.

Make sure it’s a 16Mhz ATMEGA328P board running at 5V.

Micro SD Card Connector

This is the common push-push Micro SD module with level shifters. Sometimes it may say “Catalex” (maybe the original designer?) on the back of the PCB. You will need to remove the pre-soldered right angle header they all seem to come with so you can mount it upside down on the shield board.

image-20210305180028998

Bulk Capacitor

C1 is a bulk storage capacitor for the 5V rail. It is optional since the Arduino already has caps on-board, but if you have a marginal SmartPort 5V line or experience other power issues, they could help stabilize the overall board. Any value between 10uf to 47uf is fine.

Resistors

Either 1/4W or 1/8W can be used in all locations.

R1 is the pull-down resistor for the eject button. Anything from 1K to 10K is probably fine here.

R2 through R6 controls the activity and active partition LED brightness. A good calculator is at:

http://ledcalc.com/

if you want to use something other the 470 ohm spec on the board. Just don’t exceed 20ma.