Joyce character set

The Joyce character set is composed of 256 characters (0x00-0xFF) (Find an overview here. Remarks on the ANSI character set will be found here.):

Range	Description
0x00-0x1F	Usuallay these are control characters. With the prefix ESCAPE (0x1B) these are extended characters on the Joyce.
0x20-0x7F	This is the normal printable character set except for DELETE (0x7F) which will be displayed as a character on the Joyce.
0x80-0xFF	This is the extended character set.

Inspired by the article „memory block layout" by Cliff Lawson I wrote some utilities for modifying the Joyce character set.

Program	Function
SETMAT	Read or define character sets with this assembler tool. I decided to save the binary data in ASCII format for simpler handling it by a high level language, originally BASIC. The tool reads a matrix entry using an RSX call and converts the 8 bytes into 16 ASCII characters. To define a new matrix it converts 16 ASCII characters to 8 bytes and stores them, using another RSX call. [Originally the program was written in 8080 assembler, find the Z80 version here]
CHARSET	This tool is designed as an RSX and may be called by a normal BDOS function. It may load (function 38) or save a special 8 byte matrix (function 39). [Also here a Z80 version does exist]
MATEDIT	A BASIC program for editing character sets. Create your own character sets, reading ASCII coded data and set or reset pixels in a character matrix.

Matrix Editor	Character Designer

In a first step I translated the BASIC program into TURBO-Pascal, find the source here. A big problem was the difference of file access. While BASIC allows random access, Pascal does not.
At the same time I combined SETMAT and CHARSET to SETMATV. Now reading and writing a matrix will be executed in COMMON memory without an RSX call.

In 1987 the publishing company PC Schneider International offered the Character Designer on the disk Joyce-Programmsammlung Vol. 1. Character sets may be saved as executable .COM file.
The program was written in TURBO Pascal und used the direct access of the Joyce character matrix instead of working with an external file. Handling and facility were much better than for the Matrix Editor. [Just for curiosity I decompiled the program manually, find here the main part, the required include file and the assembler include file]