diff --git a/include/platform/a8.ini b/include/platform/a8.ini
index 32ffc46e..97d6911a 100644
--- a/include/platform/a8.ini
+++ b/include/platform/a8.ini
@@ -1,3 +1,23 @@
+; Simple Atari 800XL memory map
+; by Peter Dell
+; https://youtu.be/KIl4SgV0vJY
+
+; $00-$7f zeropage for OS
+; $80-$ff zeropage for you
+; $100-$1ff CPU stack
+; $200-$2ff OS vector, registers
+; $300-$3ff OS vector, registers
+; $400-$5ff OS buffers
+; $600-$6ff Page 6, object code in BASIC
+; $700-$1fff Disk Operating System
+; $2000-RAMTOP Your code
+; $8000-$9fff Cartrige 8k/low 16k
+; $a000-$bfff Cartrige 8k/High 16k/BASIC
+; $c000-$cfff OS part 1
+; $cc00-$cfff OS character set, international
+; $e000-$ffff OS part 2
+; $e000-$e3ff OS character set, standard
+
 [compilation]
 arch=strict
 modules=a8_hardware,a8_os,a8_kernel,default_panic,stdlib
@@ -5,11 +25,11 @@ encoding=atascii
 screen_encoding=atasciiscr
 
 [allocation]
-; TODO
-zp_bytes=$80-$A5
+; OS TURN ON
+zp_bytes=$80-$FF
 segment_default_start=$2000
-; TODO
-segment_default_end=$3fff
+; BASIC TURN OFF
+segment_default_end=$bfff
 
 [define]
 ATARI_8=1
@@ -23,5 +43,3 @@ HAS_BITMAP_MODE=1
 style=single
 format=$FF,$FF,$E0,$02,$E1,$02,startaddr,startaddr,endaddr,allocated
 extension=xex
-
-