From 0f70b40f391ca1858f017396e58a1b81280fb965 Mon Sep 17 00:00:00 2001 From: Matthew Nielsen Date: Tue, 24 Jan 2017 16:56:31 -0700 Subject: [PATCH] Added note about possible shift-register improvement. --- README.md | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index b50048d..188920a 100644 --- a/README.md +++ b/README.md @@ -89,6 +89,8 @@ IIe Connector Col/Row Shift Register Input Notes #### Shift register to Teensy 2.0 +Follows DIP-8 package: http://www.ti.com/lit/ds/symlink/sn74ls165a.pdf + ``` Teensy 2.0 Pin Shift Register Pin @@ -100,7 +102,12 @@ Teensy 2.0 Pin Shift Register Pin GND 8: GND ``` -Follows DIP-8 package: http://www.ti.com/lit/ds/symlink/sn74ls165a.pdf +##### Possible improvement + +`SH/LD` is always pulled low at the same time as `CLK INH` is pulled high. That +means `CLK INH` could be driven from the same pin as `SH/LD` using a +single-transistor NOT gate. This would free another pin for an extra LED or +something. #### Other Pins