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- DIFFERENCES FROM CP/M 2.2 CCP
- DIFFERENCES FROM CP/M 2.2 BDOS
- ZRDOS EXTENDED FUNCTION CALLS
- ZRDOS UNIT RECORD FUNCTIONS
- ZRDOS DISK RELATED FUNCTIONS
- ZRDOS MISCELLANEOUS FUNCTIONS
- ZRDOS UTILITIES
- :DIFFERENCES FROM CP/M 2.2 CCP
-
- ZRDOS is a Z80 coded, CP/M 2.2 compatible disk operating
- system designed to be used with the Echelon Z80 Command Processor
- ZCPR3 by Richard Conn.
-
- ZRDOS is compatible with all of the ZCPR3 utilities. Named
- Directories, Redirectable I/O, and all other ZCPR3 features can
- used with ZRDOS. For the installation of these additional
- features please refer to the original ZCPR3 documentation
- package.
- :DIFFERENCES FROM CP/M 2.2 BDOS
-
-
- Disk Change
-
- ZRDOS allows the changing of disks without the need of a
- warm boot. CHANGED DISKS WILL BE AUTOMATICALLY LOGGED IN.
-
- NOTE: The above mentioned auto login will not occur if a file
- was open when the disk was changed and a write
- operation is attempted to that file on the new diskette
- instead the following error message will be printed:
-
- Disk Changed Error On Drive B:
-
- It should also be noted that the automatic logon may or may
- not be able to handle changes in density or number of sides. This
- depends on how your bios handles deblocking and double sided
- disks. However if the disk is of the same density and number of
- sides as the disk it is being swapped with there will be no
- problems.
-
-
-
- Read Only Disk Status
-
- Under ZRDOS a disk can only be set to R/O status by
- executing function call 28 (Protect Drive).
-
-
- ZRDOS function call 37 (Reset Drive) is different in that it
- will only reset the Read Only bits for the drive(s) specified in
- the user passed drive map in the register pair (DE). With CP/M
- function 37 will also reset the bits for any drive not currently
- active.
-
- Function call 13 (Reset Disk System) is different in that it
- will not reset drives that are set to Read Only but will instead
- reset the disk changed vector.
-
-
-
-
-
-
-
-
- Read Console Buffer
-
- The Read console buffer routine (Function 10) for ZRDOS is
- different in the following ways:
-
- . Rubout (DEL) is treated the same as a backspace.
- . The Control-R edit function is not implemented.
-
- NOTE: In CP/M these are teletype oriented edit commands and
- were felt not to be required in ZRDOS.
-
-
-
-
-
-
-
-
-
-
-
-
-
- File Archiving
-
- ZRDOS supports the use of the file archive attribute. The
- support of this feature is compatible with both CP/M 3.0 and
- MP/M. This bit when set indicates an archived file. That is a
- file which has not been altered. The bit can be set by using a
- Function 30 (Set File Attributes) function call. Any update to
- this file once the bit has been set will cause the bit to be
- reset. This can then be used by a copy utility to indicate the
- need to backup the file. The utility that backs up the file
- should then set the archive bit to indicate the file has been
- backed up.
-
-
-
-
-
-
-
-
-
-
-
- Wheel Protection
-
- ZRDOS uses the ZCPR3 wheel byte and a new file attribute bit
- to protect files from non-wheel users. This bit when set will
- write protect the file as long as the wheel byte is off. If the
- wheel byte is set the file is treated as a normal file.
-
- If a non-wheel user attempts to change a wheel protected
- file the following error message will be displayed:
-
- A0>File W/P Error on A:
-
-
-
-
-
-
-
-
-
-
-
-
- Error Messages
-
- ZRDOS CP/M
-
- Error
- Number
-
- 1 Read Error On A: Bdos Err On A:Bad Sector
- 2 Drive Select Error On A: Bdos Err On A:Select
- 3 Disk R/O Error On A: Bdos Err On A:R/O
- 4 File R/O Error On A: Bdos Err On A:File R/O
- 5 Disk Changed Error On A: n/a
- 6 File W/P Error On A: n/a
-
- With ZRDOS all non-retryable errors jump directly to warm
- boot after the error message has been printed. Read Errors allow
- the user the option of retrying the operation by pressing any key
- but control-c or aborting by pressing control-c. Error numbers
- shown above are returned in the (A) register. The selected drive
- number is returned in register (E).
-
-
-
- NOTE: If the warm boot trap (see FUNCTION 38) is set ZRDOS
- jumps directly to the warm boot vector and no error
- messages are displayed.
-
- CP/M handles the errors in the same manor except a key must
- be pressed before CP/M will return from any type of error and
- CP/M doesn't return an error or drive number. Nor does CP/M have
- a warm boot trap function.
- :ZRDOS EXTENDED FUNCTION CALLS
-
- Function 47: Get Current DMA Address
-
- This function will return the currently assigned DMA address
- in the register pair (HL).
-
-
- Function 48: Return ZRDOS Version Number
-
- This function works the same as CP/M function call 12 except
- the ZRDOS Version number is returned instead of the CP/M version
- number. To maintain CP/M compatibility ZRDOS will return version
- number 2.2 on a function 12 call. As with function 12 function 48
- uses the register pair (HL) to return the version number. If user
- programs that use the extended ZRDOS functions are written this
- function should first be used to determine if the program is
- being run under ZRDOS.
-
-
-
-
-
- Function 50: Set Warm Boot Trap
-
- A new function call is provided that allows the user to set
- a trap on warm boot to a user specified address. The trap is set
- by executing a function 50 call with the trap address in the
- register pair (DE). The Warm boot jump address at location 001H
- is replaced with the user supplied trap address. Warm boots
- executed after the trap is set will cause a jump to the trap
- address. ZRDOS error messages are suppressed allowing the user to
- print his own error messages. As noted in the ZRDOS error section
- above errors detected by ZRDOS return an error number and the
- active drive number which the user can then use to determine how
- best to handle the error.
-
- WARNING: Caution should be exercised when using this function as
- the results will be unpredictable if a program that
- has set the trap terminates without first resetting the
- trap. See FUNCTION 52 below.
-
-
-
-
-
- Function 52: Reset Warm Boot Trap
-
- This new function call will reset the warm boot trap set by
- function call 50. The trap is reset by executing a function call
- 52. The Real bios warm boot address is restored to location
- 0001H. If function call 50 is used in a user program a function
- call 52 should be executed before control is returned to the
- operating system.
- ::ZRDOS1A
- ::ZRDOS1B
- ::ZRDOS1D
- ::ZDU