DOS/65 for CRC65

Introduction

DOS/65 V3 Distribution Files

Porting DOS/65 V3 to CRC65

CRC65 Software for DOS/65

Programs assembled in Windows environment using CA65 assembler

Programs uploaded to DOS/65 to be assembled using DOS/65 native assembler

DOS/65 is a CP/M 2.2 clone for 6502 processor. It is created by Richard Leary who has released it as freeware under GNU General Public License V3. Beside the sources of DOS/65, a number of supporting programs are also available as 6502 source codes. Programs such as editor, assembler, debug, super directory, BASIC compiler, BASIC interpreter, Xmodem, and others. This is the link to discussion about porting version 3 of DOS/65 to CRC65.

DOS/65 V3 source files can be found here

Documentations for DOS/65 V3 is here

Additional source for UCOPY, SD, and SUBMIT programs

Because CRC65 bootstrap from the CF disk, the goal is creating a dedicated DOS/65 CF disk that boots directly into DOS/65 at power up. Sometimes it is desirable to have access to CRC65 hardware monitor to perform hardware level diagnostic and load hardware-specific utility software. This can be achieved by loading CRC65 monitor along with DOS/65 system files during power-on bootstrap. CRC65 monitor can be invoked by issuing a “go $b400” command at DOS/65 prompt.

By design, CRC65 loads and executes program stored in Master Boot Record of the CF disk. This bootstrap program will load CRC65 monitor and DOS/65 system program from system track of the CF disk into RAM from $b200 to top of RAM ($E7FF). Once load is completed, the bootstrap will jump to cold-boot routine of DOS/65 at $dc00.

The above screen capture shows DOS/65 booting up. The first line consists of 27 dots each representing a 512-byte CF sector copied into RAM starting from $b200; the 2nd line is DOS/65 sign on message; and the third line starts with DOS/65 command prompt, A0> which denotes Drive A, User 0.

There are two methods of installing DOS/65 on a new CF disk, The easiest method is disk copy a DOS/65 image to a new CF disk using diskcopy application such as Win32DiskImager in Windows environment. The second method is installing DOS/65 system files serially using a TeraTerm Macro script file. This zipped file contains all software needed to install DOS/65 to a new CF disk by copy all file to c:\teraterm\dos65 and execute the TeraTerm Macro, newDOS65CF_v3fast.ttl.

This is a 6+ minute YouTube video showing installation of DOS/65 via serial port.

FORMATCF, this utility program writes $E5 to directories of drive A/B/C/D, effectively format the disk for DOS/65

DOSBOOT, this utility program copies DOS/65 bootstrap to Master Boot Record and copy DOS/65 system program and CRC65 monitor to 27 sectors on the system track

DOS65V3, this is DOS/65 V3 for CRC65, SIM version 0.2

In order to upload programs into DOS/65 CF disk and use DOS/65's native assembler to assemble source codes, three executable programs must be installed in DOS/65 disk. These programs are assembled in Windows environment using CA65 assembler then upload and save in CF disk using built-in DOS/65 command “save file_size file_name”..

ASM, this is DOS/65 native 6502 assembler

MKCOM, this converts ASM output to DOS/65 executable

XMODEM, this is the xmodem file transfer program

The zipped file contains assembly sources of DOS/65 programs that can be assembled using DOS/65's native assember, ASM.COM.