XC24SYMB.BIN

Author:          SymbiosiS
Category:        Christmas Challenge
System:          Amstrad CPC 6128
Language:        Z80 Assembler
Len source code: 2939
Len exe file:    174
Len code only:   46

Instructions:
- Use WinApe emulator, ACE DL or whatever
- Insert "xc24symb.dsk"
- Type
MEMORY &13FE
LOAD"XC24SYMB
CALL &13FF

Description:
As the gift consists mainly of 1+8+1+8+1 characters in both dimensions, the
idea of this approach is to shift two 9-bit patterns for both the rows and
columns to find out if we hit a row, a column, a node or nothing (4 different
combinations).
The two leading row/column bits are used to create an index for selecting the
correct character for each position.
To save one byte (RET) the text and data behind the code is arranged and placed
in a way, that it can be reused as an endless loop.

Comments:
9bit shifter idea, call to basic rom string output by BSC;
All code, index idea, optimizations by PRODATRON
This was a collaborative project by two old friends from the Amstrad CPC
who have known each other for 2^5 years, and we really had a lot of fun!