From ca0dcd8b11c944caabfe3fcce2fa50d57bf492c1 Mon Sep 17 00:00:00 2001
From: Andrew Alderwick <andrew@alderwick.co.uk>
Date: Sat, 27 Mar 2021 11:23:20 +0000
Subject: [PATCH] Added beginnings of neralie.

---
 projects/software/neralie.usm | 160 ++++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)
 create mode 100644 projects/software/neralie.usm

diff --git a/projects/software/neralie.usm b/projects/software/neralie.usm
new file mode 100644
index 0000000..ee1b99b
--- /dev/null
+++ b/projects/software/neralie.usm
@@ -0,0 +1,160 @@
+( Prints Neralie time to console.
+
+  Formatting isn't great, but it demonstrates that
+  the conversion works correctly. It's a little jittery
+  at the beginning because the FPS calculation isn't
+  accurate, so in the finished program delay showing
+  pulses for up to the first two seconds.
+
+  When compiled to bin/boot.rom, the faketime package
+  allows easy testing of midnight roll-over:
+
+  faketime '23:59:42' bin/emulator bin/boot.rom
+)
+
+;fps { current 1 next 1 second 1 }
+;number { started 1 count 1 }
+;linee { var 2 }
+;neralie { n6543 2 n21 1 }
+
+|0100 ;Console { pad 8 char 1 byte 1 short 2 }
+|0110 ;Screen { width 2 height 2 pad 4 x 2 y 2 color 1 }
+|0120 ;Sprite { pad 8 x 2 y 2 addr 2 color 1 }
+|0190 ;Time { year 2 month 1 day 1 hour 1 minute 1 second 1 dow 1 doy 2 isdst 1 pad 4 get 1 }
+|01F0 .RESET .FRAME .ERROR ( vectors )
+|01F8 [ 13fd 1ef3 1bf2 ] ( palette )
+
+|0200 @RESET
+	#3c =fps.current
+	@ERROR BRK
+
+@FRAME
+	,update-fps JSR2
+	,neralie-calc JSR2
+	BRK
+
+	,font #00 ~number.count #08 MUL ADD2 =Sprite.addr
+	#02 =Sprite.color
+	#0000 #00 ~number.count DUP2 ,h JSR2
+	~number.count #01 ADD =number.count
+
+@neralie-calc
+	( add up fractions of a pulse )
+	#0120 #00 ~Time.hour MUL2
+	#00c0 #00 ~Time.minute MUL2 ADD2
+	#00f8 #00 ~Time.second MUL2 ADD2
+	#0271 #00 ~fps.next MUL2 #00 ~fps.current DIV2 #0008 MUL2 ADD2
+	#01b0 DIV2
+
+	( add up units and tens of pulses )
+	#0042 #00 ~Time.hour MUL2 ADD2
+	#005e #00 ~Time.minute MUL2 ADD2
+	#000b #00 ~Time.second MUL2 ADD2
+	DUP2 #0064 DIV2 DUP2 STH2 #0064 MUL2 SUB2 =neralie.n21 POP
+
+	( add up hundreds of pulses + 10 x beats )
+	STH2r
+	#01a0 #00 ~Time.hour MUL2 ADD2
+	#0006 #00 ~Time.minute MUL2 ADD2 =neralie.n6543
+
+	~neralie.n6543 ,print-short-decimal JSR2
+	#20 =Console.char
+	~neralie.n21 ,print-byte-decimal JSR2
+	#0a =Console.char
+	JMP2r
+
+@h ( x1₂ x2₂ y₂ -- )
+	=Screen.y
+	,Screen.x =linee.var
+	^line JMP
+
+@v ( y1₂ y2₂ x₂ -- )
+	=Screen.x
+	,Screen.y =linee.var
+	( ^line JMP is redundant )
+
+@line ( v1₂ v2₂ -- )
+	OVR2 OVR2 LTH2 #01 JNZ SWP2
+	STH2
+
+	$loop
+	DUP2 DUP2r STH2r GTH2 ^$end JNZ
+	DUP2 ~linee.var STR2
+	#03 =Screen.color
+	#0001 ADD2
+	^$loop JMP
+
+	$end
+	POP2 POP2r
+	JMP2r
+
+@update-fps
+	#00 =Time.get
+	~fps.next #01 ADD =fps.next
+	~Time.second ~fps.second NEQ JMP JMP2r
+	~Time.second =fps.second
+	~fps.next =fps.current
+
+	~fps.next ^print-byte-decimal JSR
+	,strings-fps ^print-string JSR
+
+	#00 =fps.next
+	JMP2r
+
+@print-byte-decimal ( byte₁ -- )
+	#00 =number.started
+	DUP #64 DIV DUP ^$digit JSR #64 MUL SUB
+	DUP #0a DIV DUP ^$digit JSR #0a MUL SUB
+	^$digit JSR
+	~number.started ^$end JNZ
+	#30 =Console.char
+	$end JMP2r
+
+	$digit
+	OVR ~number.started ORA #02 JNZ
+	POP JMP2r
+	#30 ADD =Console.char
+	#01 =number.started
+	JMP2r
+
+@print-string ( string₂ -- )
+	DUP2 PEK2 DUP ^$not-end JNZ
+
+	$end
+	POP POP2 JMP2r
+
+	$not-end
+	=Console.char
+	#0001 ADD2 ^print-string JMP
+
+@print-short-decimal ( short₂ -- )
+	#00 =number.started
+	DUP2 #2710 DIV2 DUP2 ^$digit JSR #2710 MUL2 SUB2
+	DUP2 #03e8 DIV2 DUP2 ^$digit JSR #03e8 MUL2 SUB2
+	DUP2 #0064 DIV2 DUP2 ^$digit JSR #0064 MUL2 SUB2
+	DUP2 #000a DIV2 DUP2 ^$digit JSR #000a MUL2 SUB2
+	^$digit JSR
+	~number.started ^$end JNZ
+	#30 =Console.char
+	$end JMP2r
+
+	$digit
+	SWP POP
+	OVR ~number.started ORA #02 JNZ
+	POP JMP2r
+	#30 ADD =Console.char
+	#01 =number.started
+	JMP2r
+
+@strings
+	$fps [ 20 fps 0a 00 ]
+
+@font
+[
+	003c 464a 5262 3c00 0018 0808 0808 1c00
+	003c 4202 3c40 7e00 003c 421c 0242 3c00
+	000c 1424 447e 0400 007e 407c 0242 3c00
+	003c 407c 4242 3c00 007e 0204 0810 1000
+	003c 423c 4242 3c00 003c 4242 3e02 3c00
+]
+