Dietrich-L/CPM-65_for_JUNIOR_COMPUTER_II

CPM-65 Junior Computer II Port
===========
Dietrich Lausberg
https://github.com/dietrich-l

This repository contains the Junior Computer II Port of CPM-65,
a CP/M-80 analogue operating system for 6502 based microcomputers

![4_BOOT](https://github.com/Dietrich-L/CPM-65_for_JUNIOR_COMPUTER_II/assets/83355183/2ed79c93-dfbe-426f-b827-fa08cdfe25a0)

System Requirements
--------------------------

Junior Computer II
Expansion Card

Special thanks for support and testing goes to
Joerg Walke, Developer of the Junior Computer II system, Norbert J. and Edzard

System Structure
--------------------

CPM-65 consists of 3 layers:

- BIOS Basic I/O system - Drives can be A-D non consecutive.
- BDOS Basic disc operating system - this is the CPM-65 kernal. Size 2 kB
- CCP Console command program - a simple console which only allows to invoke CPM-65 programs.
No resident commands. Size 1 kB

On the JC ][ CPM-65 resides on 1 MB images on a SD card. Upon Boot the JC ][ first executes a
program in BOOT.SYS in the root directory of the SD. BOOT.SYS offers all bootable images found
in the Root directory for booting. The images must have the CPM-65 system in sectors 1 to 11.
The program then loads CPM-65 to memory, mounts the selected image as Drive A: via a BIOS call
and starts the CCP. Up to 4 images can be mounted with the utility SD-UTIL.
A more detailed description how to prepare a bootable SD card can be found
under [docs/CPM-65 JC-II BOOT preparations.txt](https://github.com/Dietrich-L/CPM-65_for_JUNIOR_COMPUTER_II/blob/master/docs/CPM-65%20JC-II%20BOOT%20preparations.txt)

File & Disc Format
----------------------

Filenames are CP/M-style d:filename.ext with d <Drive A-D>
Programs must have .COM as extension and are loaded to $2000 and started there.

The directory structure is nearly CP/M-compatible. Disk images can be read with appropriate tools
like CPMTOOLS, CIFE (CPM Image File Explorer) or CpmtoolsGUI. A disdefs file is in the IMAGES section.

The Disc format is 128 tracks/ 32 sectors/ 256 byte/sector.
It is defined in the BIOS. The BDOS operates on sector numbers.

Software List

Program	Version	Description
ALLOC	2.9	shows disc allocation map
ASM	2.8	native 6502 Assembler
BASIC	1.6	Microsoft Basic interpreter
BDOS	2.4	CPM-65 BDOS
BIOS	1.1	JC II CPM-65 BIOS
BOOT	1.3	JC II CPM-65 BOOT program in track 0, sector 0
BOOTSYS	1.8	JC II CPM-65 BOOT program on SD, main directory
BROWSE	1.2	text file browser
CCP	1.5	CPM-65 CCP
COPY	1.4	multi file copy utility
D	2.3	show directory alphabetically sorted
DEBUG	1.9	Debugger, 8 breakpoints, stepping, disassembler,...
DUTIL	1.5	disc sector editor
EDIT	1.1	Simple editor for text files & FORTH screens
ERASE	1.5	erase files
FDISK	1.0	Disk initializer
FORTH	1.6	FIG FORTH including module for standalone applications
RENAME	1.1	rename files
SD-UTIL	1.5	SD utility for image handling and sector inspection
SYS	1.6	puts code for BOOT, BIOS, BDOS, CCP into the system tracks
SYSGEN	1.0	copy operating system to another disc
TYPE	1.7	prints text file to screen
XMODEM	2.3	File transfer XMODEM protocol, via serial I/O 19200 Baud