From: Martin Mares <mj@ucw.cz>
Date: Sun, 21 Nov 2010 22:11:39 +0000 (+0100)
Subject: Minsk: Document the registers
X-Git-Tag: v1.0~18
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=53b9d1da805cf4e676c3a583265cdd930c5fc5af;p=minsk.git

Minsk: Document the registers
---

diff --git a/INSTRUCTIONS b/INSTRUCTIONS
index 62c8d95..7e3f8f0 100644
--- a/INSTRUCTIONS
+++ b/INSTRUCTIONS
@@ -26,6 +26,17 @@ Data format:
 		5 bits of exponent (2 decimal digits in BCD, the former one truncated to 1 bit)
 
 
+Registers:
+
+Minsk-2 has 3 registers:
+
+	accumulator	usually keeps the result of the previous arithmetic operation
+	R1		usually copies one of the operand of the instruction
+	R2		contains the value of acc
+
+(most programs use only the accumulator)
+
+
 Generic instruction format:  (by octal digits; some instructions deviate)
 
 sop mm xxxx yyyy