From cf5c3226239cfdf389614b92c2ef3746a33391ae Mon Sep 17 00:00:00 2001
From: Eugene Lozovoy <uzix.ls@gmail.com>
Date: Mon, 17 Apr 2023 12:57:23 +0300
Subject: [PATCH] add readme

---
 README.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 README.md

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..7233707
--- /dev/null
+++ b/README.md
@@ -0,0 +1,17 @@
+##  Alternate firmware for ZXKIT1 VGA scandoubler for ZX Spectrum
+
+PCB: https://github.com/romychs/RGB2VGA
+
+* Low delay (one line)
+* Automatically adjust to input timings
+* Automatically detect input VSYNC(KSI), HSYNC(SSI) polarity. Supported schemes: V+ H+ and V- H-
+* Support for CSYNC (composite sync) input (should be connected to SSI input, KSI should be pulled hight)
+
+Jumpers:
+* INVERSE_RGBI - changes polarity of *input* RGBI signals
+* INVERSE_KSI - changes polarity of *output* VSYNC signal
+* INVERSE_SSI - changes polarity of *output* HSYNC signal
+* INVERSE_F14MHZ - changes edge of clock to latch input RGBI signal
+* VGA_SCART - no effect
+* SET_FK_IN - no effect
+* SET_FK_OUT - no effect