The A3977SED is now A3977KED. Either P/N is acceptable.
Digikey P/N 620-1076-ND
MACH3 Users please note: Substitute 2.2K ohm resistors for R17, R18 and R4 in place of the 10K values. Set Step and Pulse widths to 5us.
To print the copper bit maps from IE, place the cursor over the link of the copper bitmap file you want
click "save as". This will place the file on your local machine (in a folder of your selection, Desktop makes
it easy). Open the file with Microsoft Photo Editor, under File > Properties set the Resolution to
Rev A, just changes the physical layout to add more copper for heat sink purposes