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BDOS replacements for CP/M 2 and 3

There are a number of public domain replacements for the CP/M BDOS. Here are their feature lists, extracted from their own documentation:

For CP/M 2

Z80DOS

• Version 1.0
  • All the features of P2DOS;
  • New calls to get and set time stamps.
• Version 2.3 adds:
  • Fast directory search system;
  • Can be assembled as a ZRL file for the Z-System;
  • Call to detect presence of Z80DOS.
• Version 2.4 adds:
  • Fast disc reset capability has been;
  • Z80DOS can now be assembled with Z80MR;
  • All the internal data bases have been moved for compatibility with other replacement BDOSses.

DOS +

Not to be confused with Digital Research's DOS Plus (a PC operating system, based on CP/M-86, which emulates PCDOS).

• Will process files of up to 262,143 records;
• Allows for time-stamping of all files (not CP/M 3 compatible);
• Has CP/M 3 compatible direct console I/O;
• Always pauses when ^S is typed;
• Can be interrupted at any BDOS call (if so configured);
• Errors show the calling function, and the file name;
• Implements the CPM3 calls 104 and 105 (set/get time);
• Setuser call (32 = 020h) echoes the user # set;
• Implements a search path;
• Makes all System files, on user area 0, visible to all users for read;
• Maintains the Archive attribute;
• Supports exact file lengths;
• Scans user area 0 for any file names beginning with '$';
• "Compatibility" mode for CP/M 2 programs.

P2DOS

• Changing discs without Control-C;
• Public files;
• Enhanced error messages;
• File date and time stamping (probably not CP/M 3 compatible);
• Free interchange of double and single-sided discs;

NovaDOS

• Two kinds of Public files are supported;
• A search path is available which will access system and public files in directories other than the default;
• The archive file attribute bit is supported;
• Console Status may be checked after every 256 characters of output;
• Time and date stamping of files is supported;
• Two different methods are provided for sensing the change between single and double sided floppy discs on computers which support both formats;
• Automatic logon of changed discs is supported;
• Permanent media (hard and RAM discs) are supported by a permanent media vector and a fast disc reset option;
• An internal flags byte is available;
• Error messages have been greatly improved;
• The delete key works like a backspace under function 10;
• Functions may be assembled into NovaDOS to support software designed to run under ZRDOS;
• Support for high bit character I/O may be enabled in the assembly;
• Disk size can be as large as 65536 * 16K = 1 G byte;
• File size can be as large as 32 * 64 * 16K = 32 M byte.

ZSDOS

• Available under the GNU GPL.
• "Direct" console I/O can be mixed with the normal sort.
• Fast disc reset for hard drives.
• Can detect disk changes automatically.
• DMA address can be returned.
• Re-entrant.
• BDOS error mode can be turned on/off.
• Improved error messages.
• 1G max disk size, 32Mb max file size.
• Optional public directories / public files.
• Timestamps are supported by a loadable module, so either the CP/M 3 style or the DateStamper style can be used.

For CP/M 3

ZPM3

• An obscure bug in the Read Random Record routine has been fixed;
• The user number in the SCB is protected against tampering;
• The clumsy "Trap" system for I/O redirection has been made obsolete;
• Drives set by software to Read-Only stay that way until specifically set to Read-Write;
• Filenames with user numbers are parsed correctly;
• Z80DOS compatible datestamp calls;
• Wheel protection of files (with ZCCP);
• Expanded error messages;
• Command history buffer and improved line editor;
• Bug fix in the CP/M boot loader.

FreeDOS

The FreeDOS project is an attempt to write a free replacement for MSDOS. Try here for more information.

DR-DOS

See www.drdos.com for DR-DOS; this is still a commercial product.

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