Add images for the two PC cable types

Author: btb

README.md

@@ -25,6 +25,10 @@ The original SSC used a 1.8432MHz crystal (Y1) and a usually-omitted 10pF capaci
 
 You can use a common PC-type IDC10 to DB9M pigtail, or the IDC10 to DB25F pigtail used with the original Apple SSC. There are two different pinouts used in the PC style ("sequential" or "staggered"), and the "apple" pinout is different from both. Only populate the header (J1) for the style you're going to use. "sequential" is the most commonly available type. A keyed/shrouded header is probably best, a right angle/horizontal header would be nice, but you probably only have room for that if you are using the "apple" pinout.
 
+![DB9M Sequential](cables/DB9MSequential.jpg)
+![DB9M Staggered](cables/DB9MStaggered.jpg)
+Sequential, Left. Staggered, Right
+
 ### Driver/Receiver
 
 The RS232 Driver/Receiver chips, UA6 and UA7, can be the original 1488 and 1489 or the CMOS equivalent 14C88 and 14C89. If UA6 is a 14C88, you can omit capacitors C3, C4, and C9.