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--- sd:sd-8516_stellar_basic [2026/03/28 13:21] – appledog
+++ sd:sd-8516_stellar_basic [2026/04/05 14:18] (current) – appledog
@@ Line 13: / Line 13: @@
 There are some basic terminal interface commands you may wish to know. These will allow you to make character mode games; see next chapter for graphics mode.
-* STRXY A$, X, Y -- print string at XY on the screen
+* STRXY X, Y, A$ -- print string at XY on the screen
 * CHARXY X, Y, C -- puts character C (0-255) on the screen at location (X,Y).
 * CHARFG X,Y,FG -- changes the foreground color of a single character on the screen
@@ Line 240: / Line 240: @@
 VSTART will resume regular video chip scans of the framebuffer to video memory.
+=== Mode 4
+Mode 4 is a 256x224 "Famous Console" inspired mode. Here's a demo program:
+<codify>
+MODE 4
+FOR C = 0 TO 15
+RECT C * 16, 0, C * 16 + 15, 223, C, 1
+NEXT C
+LINE 0, 0, 223, 223, 3
+INPUT "PRESS ENTER"; A$
+MODE 1
+</codify>
+As you can see, it's pretty much more of the same, but you may prefer the aspect ratio for classic 8bit and 16bit console games.
+=== Mode 8
+Mode 8 is a 128x128 "Ersatz-8" inspired mode.
+<codify>
+MODE 8
+FOR C = 0 TO 15
+RECT C * 8, 0, C * 8 + 7, 127, C, 1
+NEXT C
+LINE 0, 0, 127, 127, 3
+INPUT "PRESS ENTER"; A$
+MODE 1
+</codify>
+As you can see, it's pretty much more of the same, but you may prefer this aspect ratio for classic "ersatz retro" games.
 == Music
@@ Line 379: / Line 410: @@
 === Further Study
 If you wish to learn more about how the MML system works under the hood, please refer to the Programmer's Reference Guide [[Appendix 5 Sound System]].
+== Benchmarking your Code
+You might want to know how fast your code runs. This simple benchmarking program gives you an insight on how to create a simple timer:
+<codify BASIC>
+BANK 1
+LET T=PEEK($EF06)
+FOR I=1 TO 1000
+LET A=I*3+7
+LET B=A/2-1
+LET C=A+B
+LET S=S+C
+IF C>100 THEN LET P=P+1
+NEXT I
+LET U=PEEK($EF06)
+LET D=U-T
+PRINT D
+</codify>
+The memory location $EF06 is the second byte of the hardware clock, which ticks once every .256 seconds. it's a bit rough but if you need a simple timer you can do something like this. On my computer this returns 14, which indicates 7000/(14*.256) or 1,953 BASIC lines per second. Of course, we already have the WAIT command so this is not useful for waiting on time; but rather it can be used to measure approximately how long something took.
+== Dictionary
+=== FREE()
+This is like MEM in that it calculates the free space in bank 0 between the end of the BASIC program and VARTOP, however it returns it as an integer. Be careful because in BASIC integers are signed. So read the number like this; when it is negative, this shows how much space has been used (the zero page is reserved so it always shows -256 at start). When it is positive, then it shows how much space is left.
+Also see: MEM
+=== MEM
+This command calculates the free space in bank 0 between the end of the BASIC program and VARTOP, which roughly estimates how much free space you have left in bank 0 for BASIC.
+Also see: FREE()
+=== PRINT
+This command prints a number, expression, variable or string. Examples:
+    PRINT "HELLO WORLD!"
+    PRINT A$
+    PRINT ASC("*")
+    PRINT 5