diff --git a/5a-75b/blink/blink_v82.lpf b/5a-75b/blink/blink_v82.lpf
new file mode 100644
index 0000000..ba8d370
--- /dev/null
+++ b/5a-75b/blink/blink_v82.lpf
@@ -0,0 +1,6 @@
+
+LOCATE COMP "osc_clk25"         SITE "P6";
+LOCATE COMP "led"               SITE "T6";
+LOCATE COMP "button"            SITE "R7";
+LOCATE COMP "phy_rst_"          SITE "R6";
+LOCATE COMP "bomb"              SITE "C4";
diff --git a/5a-75b/playground/.gitignore b/5a-75b/playground/.gitignore
new file mode 100644
index 0000000..46ece4c
--- /dev/null
+++ b/5a-75b/playground/.gitignore
@@ -0,0 +1,2 @@
+.*.swp
+build/
diff --git a/5a-75b/playground/Makefile b/5a-75b/playground/Makefile
new file mode 100644
index 0000000..77794ac
--- /dev/null
+++ b/5a-75b/playground/Makefile
@@ -0,0 +1,28 @@
+all:build/playground.svf build/playground.bit
+
+SYNTH_SRCS=main.v
+
+PACKAGE=CABGA256
+LFP=blink_v82.lpf
+
+build/playground.json: $(SYNTH_SRCS)
+	yosys -p 'read_verilog $(SYNTH_SRCS); synth_ecp5 -top playground -abc9 -json $@'
+
+build/playground.config: build/playground.json $(LPF)
+	nextpnr-ecp5 --25k --package $(PACKAGE) --speed 6 --lpf $(LFP) --json build/playground.json --textcfg build/playground.config --freq 25
+
+build/playground.svf: build/playground.config
+	ecppack --compress --input $< --svf $@
+
+build/playground.bit: build/playground.config
+	ecppack --compress --input $< --bit $@
+
+prog: build/playground.bit
+	openFPGALoader -c usb-blaster --vid 0x09fb --pid 0x6001 build/playground.bit
+
+flash: build/playground.bit
+	# ERASES THE DEFAULT CONTENTS OF THE SPI FLASH!
+	openFPGALoader -c usb-blaster --vid 0x09fb --pid 0x6001 --unprotect-flash -f build/playground.bit
+
+clean:
+	rm -f build/*
diff --git a/5a-75b/playground/blink_v82.lpf b/5a-75b/playground/blink_v82.lpf
new file mode 100644
index 0000000..ba8d370
--- /dev/null
+++ b/5a-75b/playground/blink_v82.lpf
@@ -0,0 +1,6 @@
+
+LOCATE COMP "osc_clk25"         SITE "P6";
+LOCATE COMP "led"               SITE "T6";
+LOCATE COMP "button"            SITE "R7";
+LOCATE COMP "phy_rst_"          SITE "R6";
+LOCATE COMP "bomb"              SITE "C4";
diff --git a/5a-75b/playground/main.v b/5a-75b/playground/main.v
new file mode 100644
index 0000000..bd7b847
--- /dev/null
+++ b/5a-75b/playground/main.v
@@ -0,0 +1,20 @@
+`default_nettype none
+
+module playground(
+    input  wire         osc_clk25,
+    input  wire         button,
+    output wire         led,
+    output wire         phy_rst_
+);
+
+    reg [25:0] cntr = 0;
+
+    always @(posedge osc_clk25)
+    begin
+        cntr    <= cntr + 1;
+    end
+
+    assign led = cntr[23] ^ button;
+    assign phy_rst_     = 1'b1;
+
+endmodule
\ No newline at end of file