BDOS system calls (8-bit and 16-bit)
So far, this list covers CP/M 1, 2 and 3. In general,
"CP/M 3 and above" means CP/M 3 and DR's DOS Plus:
LD DE,parameter
LD C,function
CALL 5
becomes:
MOV DX,parameter
MOV CL,function
INT 0E0h
while values are returned in AX and BX rather than BA and HL. This system
is supported in DR Multiuser DOS.
Note that DOS + is a CP/M extended BDOS, DOS Plus is a PC operating system
compatible with CP/M-86 and PCDOS 2.
If you have detailed information on MP/M, CP/Net, DOS Plus v2.1, CP/M-86 or
Concurrent CP/M - please let me know! (See note on the homepage for my email address).
Supported by: CP/M 1, 2, 3.
Entered with C=0. Does not return.
Quit the current program, return to command prompt. This call is hardly
ever used since the RST 0 instruction does the same thing and saves
four bytes.
Supported by: DOS Plus.
Entered with CL=0, DL=0 or 1. Does not return.
Quit the current program, return to command prompt.
If DL is 0, the memory used by the program is deallocated; if DL is 1,
it remains resident.
Supported by: All versions
Entered with C=1. Returns A=L=character.
Wait for a character from the keyboard; then echo it to the screen and
return it.
Supported by: All versions
Entered with C=2, E=ASCII character.
Send the character in E to the screen. Tabs are expanded to spaces. Output
can be paused with ^S and restarted with ^Q (or any key under versions prior
to CP/M 3). While the output is paused, the program can be terminated with ^C.
Supported by: All versions
Entered with C=3. Returns A=L=ASCII character
Note that this call can hang if the auxiliary input never sends data.
Supported by: All versions
Entered with C=4, E=ASCII character.
If the device is permanently not ready, this call can hang.
Supported by: All versions
Entered with C=2, E=ASCII character.
If the printer is permanently offline or busy, this call can hang.
Supported by: All versions, with variations
Entered with C=6, E=code. Returned values (in A) vary.
- E=0FFh
- Return a character without echoing if one is waiting; zero if none is available.
- E=0FEh
- [CP/M3, NovaDOS, Z80DOS, DOS+] Return console input status. Zero if no character is waiting, nonzero otherwise.
- E=0FDh
- [CP/M3, DOS+] Wait until a character is ready, return it without echoing.
- E=0FCh
- [DOS+] One-character lookahead - return the next character waiting but leave it in the buffer.
Values of E not supported on a particular system will output the character.
Direct console functions may interact undesirably with non-direct ones,
since certain buffers may be bypassed. Try not to mix them.
Supported by: CP/M 2 and lookalikes
Entered with C=7. Returns I/O byte.
Here's a description of how the IOBYTE works.
Supported by: CP/M 3 and above
Entered with C=7. Returns A=0 or 0FFh.
0FFh is returned if the Auxiliary Input device has a character ready;
otherwise 0 is returned.
Supported by: CP/M 2 and lookalikes
Entered with C=8, E=I/O byte.
Here's a description of how the IOBYTE works.
Supported by: CP/M 3 and above
Entered with C=8. Returns A=0 or 0FFh.
0FFh is returned if the Auxiliary Output device is ready for characters;
otherwise 0 is returned.
Supported by: All versions
Entered with C=9, DE=address of string.
Display a string of ASCII characters, terminated with the $ character.
Thus the string may not contain $ characters - so, for example, the VT52
cursor positioning command ESC Y y+32 x+32 will not be able to
use row 4.
Under CP/M 3 and above, the terminating character can be changed using BDOS function
110.
Supported by: All versions, with variations
Entered with C=0Ah, DE=address or zero.
This function reads characters from the keyboard into a memory buffer
until RETURN is pressed. The Delete key is handled correctly. In later
versions, more features can be used at this point; ZPM3 includes a full
line editor with recall of previous lines typed.
On entry, DE is the address of a buffer. If DE=0 (in CP/M-86, DOS Plus etc, DX=0FFFFh), the
DMA address is used (CP/M 3 and later) and the buffer
already contains data:
DE=address: DE=0 / DX=0FFFFh:
buffer: DEFB size buffer: DEFB size
DEFB ? DEFB len
DEFB bytes DEFB bytes
The value at buffer+0 is the amount of bytes available in the buffer. Once
the limit has been reached, no more can be added, although the line editor
can still be used.
If DE=0 (in CP/M-86, DOS Plus etc, DX=0FFFFh) the next byte contains
the number of bytes already in the buffer; otherwise this is ignored.
On return from the function, it contains the number of bytes present in the buffer.
The bytes typed then follow. There is no end marker.
Supported by: All versions
Entered with C=0Bh. Returns A=L=status
Returns A=0 if no characters are waiting, nonzero if a character is waiting.
Supported by: Version 1
Entered with C=0Ch. Returns HL=0
Has no effect except to return HL=0.
Supported by: Versions 2.0 and later
Entered with C=0Ch. Returns B=H=system type, A=L=version number.
The system type is subdivided into a machine type and a CP/M type. The
machine type occupies the high nibble of the byte; the CP/M type occupies
the low nibble.
Machine types: CP/M types: Version numbers:
0 - 8080 0 - CP/M 00h - Version 1 (see above)
1 - 8086 1 - MP/M 20h - Version 2.0
2 - CP/Net 21h - Version 2.1
22h - Version 2.2
25h - Version 2.5 (DOS +)
30h - Version 3.0
31h - Version 3.1
41h - Version 4.1 (DOS Plus 1)
60h - Version 6.0 (DOS Plus 2)
It is interesting to note that the version numbers returned by DRDOS and
Novell DOS follow this system; DRDOS 5 is version 6.5, DRDOS 6 is version
6.7 and Novell DOS 7 is version 7.2.
Supported by: All versions.
Entered with C=0Dh. Returned values vary.
Resets disk drives. Logs out all disks and empties disk buffers. Sets
the currently selected drive to A:. Any drives set to Read-Only in software
become Read-Write; replacement BDOSses tend to leave them Read-Only.
In versions 1 and 2, logs in drive A: and returns 0FFh if there is a
file present whose name begins with a $, otherwise 0. Replacement BDOSses
may modify this behaviour.
Supported by: All versions
Entered with C=0Eh, E=drive number. Returns L=A=0 or 0FFh.
The drive number passed to this routine is 0 for A:, 1 for B: up to
15 for P:.
Sets the currently selected drive to the drive in A; logs in the disc.
Returns 0 if successful or 0FFh if error. Under CP/M 3 and later, H can contain a
physical error number.
Supported by: All versions
Entered with C=0Fh, DE=FCB address. Returns error codes in BA and HL.
This function opens a file to read or read/write. The FCB is a 36-byte
data structure, most of which is maintained by CP/M. Look
here for details.
The FCB should have its DR, Fn and Tn fields filled in, and the four fields
EX, S1, S2 and RC set to zero. Under CP/M 3 and later, if CR is set to 0FFh then on return
CR will contain the last record byte count. Note
that CR should normally be reset to zero if sequential access is to be used.
Under CP/M 3 and later, a password can be supplied to this function by pointing the
DMA address at the password.
On return from this function, A is 0FFh for error, or 0-3 for success. Some
versions (including CP/M 3) always return zero; others return 0-3 to indicate
that an image of the directory entry is to be found at (80h+20h*A).
If A=0FFh, CP/M 3 returns a hardware error in H and B. It also
sets some bits in the FCB:
- F7' is set if the file is read-only because writing is password protected and no password
was supplied;
- F8' is set if the file is read-only because it is a User 0 system file opened from another
user area.
Supported by: All versions
Entered with C=10h, DE=FCB address. Returns error codes in BA and HL.
This function closes a file, and writes any pending data. This function should
always be used when a file has been written to.
On return from this function, A is 0FFh for error, or 0-3 for success. Some
versions always return zero; others return 0-3 to indicate that an image of the
directory entry is to be found at (80h+20h*A).
Under CP/M 3, if F5' is set to 1 then the pending data are written and the file
is made consistent, but it remains open.
If A=0FFh, CP/M 3 returns a hardware error in H and B.
Supported by: All versions
Entered with C=11h, DE=address of FCB. Returns error codes in BA and HL.
Search for the first occurrence of the specified file; the filename should be
stored in the supplied FCB. The filename can include ? marks, which match anything
on disc. If the first byte of the FCB is ?, then any directory entry (including
disc labels, date stamps etc.) will match. The EX byte is also checked; normally it
should be set to zero, but if it is set to ? then all suitable extents are matched.
Returns A=0FFh if error (CP/M 3 returns a hardware error
in H and B), or A=0-3 if successful. The value returned can be used to calculate the
address of a memory image of the directory entry; it is to be found at DMA+A*32.
Supported by: All versions
Entered with C=12h, (DE=address of FCB)?. Returns error codes in BA and HL.
This function should only be executed immediately after function 17 or another invocation
of function 18. No other disc access functions should have been used.
Function 18 behaves exactly as number 17, but finds the next occurrence of the specified
file after the one returned last time. The FCB parameter is not documented, but Jim Lopushinsky
states in LD301.DOC:
In none of the official Programmer's Guides for any version of
CP/M does it say that an FCB is required for Search Next (function 18).
However, if the FCB passed to Search First contains an unambiguous
file reference (i.e. no question marks), then the Search Next function
requires an FCB passed in reg DE (for CP/M-80) or DX (for CP/M-86).
Supported by: All versions
Entered with C=13h, DE=address of FCB. Returns error codes in BA and HL.
Deletes all directory entries matching the specified filename. The name
can contain ? marks. Returns A=0FFh if error, otherwise 0-3 (CP/M 3 returns
a hardware error in H and B).
Under CP/M 3, if bit F5' is set to 1, the file remains but any password
protection is removed. If the file has any password protection at all, the
DMA address must be pointing at the password when this
function is called.
Entered with C=14h, DE=address of FCB. Returns error codes in BA and HL.
Supported by: All versions
Load a record (normally 128 bytes, but under CP/M 3 this can be a multiple
of 128 bytes) at the previously specified DMA address.
Values returned in A are:
- 0
- OK,
- 1
- end of file,
- 9
- invalid FCB,
- 10
- media changed,
- 0FFh
- hardware error.
If on return A is not 0FFh, H contains the number of 128-byte records
read before the error (CP/M 3 only).
Supported by: All versions
Entered with C=15h, DE=address of FCB. Returns error codes in BA and HL.
Write a record (normally 128 bytes, but can be a multiple of 128 bytes)
to be found at previously specified DMA address. Values
returned in A are:
- 0
- OK,
- 1
- directory full,
- 2
- disk full,
- 9
- invalid FCB,
- 10
- media changed,
- 0FFh
- hardware error.
If on return A is not 0FFh, H contains the number of 128-byte records
written before the error (CP/M 3 only).
Supported by: All versions
Entered with C=16h, DE=address of FCB. Returns error codes in BA and HL.
Creates the file specified. Returns A=0FFh if the directory is full.
If the file exists already, then the default action is to return to
the command prompt, but CP/M 3 may return a hardware error
instead. Under CP/M 3, set F6' to create the file with a password; the DMA address
should point at a 9-byte buffer:
DEFS 8 ;Password
DEFB 1 ;Password mode
Supported by: All versions
Entered with C=17h, DE=address of FCB. Returns error codes in BA and HL.
Renames the file specified to the new name, stored at FCB+16. This function cannot
rename across drives so the "drive" bytes of both filenames should be identical.
Returns A=0-3 if successful; A=0FFh if error. Under CP/M 3, if H is zero then the
file could not be found; if it is nonzero it contains a hardware error
number.
Supported by: All versions
Entered with C=18h. Returns bitmap in HL.
Bit 7 of H corresponds to P: while bit 0 of L corresponds to A:. A bit is set if
the corresponding drive is logged in.
Supported by: All versions
Entered with C=19h. Returns drive in A.
Returns currently selected drive. 0 => A:, 1 => B: etc.
Supported by: All versions
Entered with C=1Ah, DE=address.
Set the Direct Memory Access address; a pointer to where CP/M should read or write data.
Initially used for the transfer of 128-byte records between memory and disc, but over the
years has gained many more functions.
Supported by: All versions, but differs under v3.
Entered with C=1Bh. Returns address in HL.
Return the address of the allocation bitmap (which blocks are used and which are free) in HL.
Under banked CP/M 3, this will be an address in bank 0 (the system bank) and not easily accessible.
Under previous versions, the format of the bitmap is a sequence of bytes, with bit 7 of
the byte representing the lowest-numbered block on disc, and counting starting at block 0
(the directory). A bit is set if the corresponding block is in use.
Under CP/M 3, the allocation vector may be of this form (single-bit) or allocate two bits
to each block (double-bit). This information is stored in the SCB.
Supported by: All versions, with differences
Entered with C=1Ch.
Temporarily set current drive to be read-only; attempts to write to it will fail. Under genuine
CP/M systems, this continues until either call 13 (disc reset) or call
37 (selective disc reset) is called; in practice, this means that whenever
a program returns to the command prompt, all drives are reset to read/write. Newer BDOS
replacements only reset the drive when function 37 is called.
Supported by: All versions
Entered with C=1Dh. Returns bitmap in HL.
Bit 7 of H corresponds to P: while bit 0 of L corresponds to A:. A bit is set if
the corresponding drive is set to read-only in software.
Supported by: All versions
Entered with C=1Eh, DE=address of FCB. Returns error codes in BA and HL.
Set and reset the bits required. Standard CP/M versions allow the bits
F1', F2', F3', F4', T1' (read-only), T2' (system) and T3' (archive) to be changed.
Some alternative BDOSses allow F5', F6', F7' and F8' to be set, but this is not to be
encouraged since setting these bits can cause CP/M 3 to behave differently.
Under CP/M 3, the Last Record Byte Count is set by storing the required
value at FCB+32 (FCB+20h) and setting the F6' bit.
The code returned in A is 0-3 if the operation was successful, or 0FFh if there was an error.
Under CP/M 3, if A is 0FFh and H is nonzero, H contains a hardware error.
Supported by: CP/M 2 and later.
Entered with C=1Fh. Returns address in HL.
Returns the address of the Disc Parameter Block for the current drive. See the
formats listing for details of the DPBs under various CP/M versions.
Supported by: CP/M 2 and later.
Entered with C=20h, E=number. If E=0FFh, returns number in A.
Set current user number. E should be 0-15, or 255 to retrieve the current
user number into A. Some versions can use user areas 16-31, but these should
be avoided for compatibility reasons.
DOS+ returns the number set in A.
Supported by: CP/M 2 and later.
Entered with C=21h, DE=FCB address. Returns error codes in BA and HL.
Read the record specified in the random record count area of the FCB, at the
DMA address. The pointers in the
FCB will be updated so that the next record to read using the sequential I/O calls will be
the record just read. Error numbers returned are:
- 0
- OK
- 1
- Reading unwritten data
- 4
- Reading unwritten extent (a 16k portion of file does not exist)
- 6
- Record number out of range
- 9
- Invalid FCB
- 10
- Media changed
- 0FFh
- [CP/M 3] hardware error in H.
Supported by: CP/M 2 and later.
Entered with C=22h, DE=FCB address. Returns error codes in BA and HL.
Write the record specified in the random record count area of the FCB, at the
DMA address. The pointers in the
FCB will be updated so that the next record to write using the sequential I/O calls will be
the record just written. Error numbers returned are:
- 0
- OK
- 2
- Disc full
- 3
- Cannot close extent
- 5
- Directory full
- 6
- Record number out of range
- 9
- Invalid FCB
- 10
- Media changed
- 0FFh
- [CP/M 3] hardware error in H.
If the record indicated is beyond the end of the file, the record will be
written and the file may contain a gap; attempting to read this gap may give
"reading unwritten data" errors, or nonsense.
Supported by: CP/M 2 and later.
Entered with C=23h, DE=FCB address. Returns error codes in BA and HL.
Set the random record count bytes of the FCB to the number of 128-byte records
in the file. Returns A=0FFh if error (file not found, or CP/M 3
hardware error); otherwise A=0.
Supported by: CP/M 2 and later.
Entered with C=24h, DE=FCB address.
Set the random record count bytes of the FCB to the number of the last record
read/written by the sequential I/O calls.
Supported by: CP/M 2 and later.
Entered with C=25h, DE=bitmap of drives to reset. Returns A=0.
Bit 7 of D corresponds to P: while bit 0 of E corresponds to A:. A bit is set if
the corresponding drive should be reset. Resetting a drive removes its software
read-only status.
Supported by: MP/M, Concurrent CP/M.
Supported by: MP/M, Concurrent CP/M.
Supported by: CP/M 2 and later.
Entered with C=28h, DE=FCB address. Returns error codes in BA and HL.
As function 34, but if the write is to a newly allocated
disc block the remainder of the block is filled with zeroes.
Supported by: MP/M, Concurrent CP/M.
Supported by: MP/M, Concurrent CP/M.
Supported by: MP/M, Concurrent CP/M.
Supported by: CP/M 3 and later.
Entered with C=2Ch, E=number of records. Returns A=0 or 0FFh.
Sets the number of records that functions 14, 15, 31, 32 and 40
should attempt to read at once. E should be 1-127. Returns A=0 if E was valid, 0FFh otherwise.
The random access counters still operate with 128 bytes/record.
Supported by: CP/M 3 and later.
Entered with C=2Dh, E=action.
Instructs CP/M 3 what action to take if there is a hardware error:
- E < 254
- Compatibility mode; program is terminated and an error message printed.
- E = 254
- Error code is returned in H, error message is printed.
- E = 255
- Error code is returned in H, no error message is printed.
Note that the messages (if printed) are not followed by a carriage return or linefeed.
Supported by: CP/M 3.
Entered with C=2Eh, E=drive. Returns error codes in BA and HL.
Sets the three bytes at the DMA address to the number of free
128-byte records on the disc, low byte first. E is the drive (0 for A:, 1 for B: etc.).
If on return A=0FFh, there is a hardware error in H.
Supported by: CP/M 3 and later.
Entered with C=2Fh, E=chain flag. Does not return.
Execute the command line at 80h. The error return code is not changed, so
the new program can discover the status returned by the previous one.
If E=255, then the currently set drive and user (as set by calls 25 and
32 become those used by the CCP; otherwise the CCP drive and user remain
the same.
Supported by: CP/M 3 and later.
Entered with C=30h, E=flag. Returns error codes in BA and HL.
Forces all pending disc writes to be executed. If E=255, then all disc read buffers are
emptied as well (so that information must be read from the disc - used by file verification
programs).
Returns A=0FFh if there is a hardware error in H.
Supported by: CP/M 3.
Entered with C=31h, DE=address of parameter area. Returned values vary.
The SCB is a 100-byte area of memory (officially) used for storing
system settings. The parameter area is formed:
pb+0: DB offset ;0-99
pb+1: DB command ;0 => Read byte at offset into A, and word at offset into HL.
;0FEh => Write word at pb+2 to SCB at offset and offset+1
;0FFh => Write byte at pb+2 to SCB at offset
Supported by: DOS Plus.
Entered with CL=31h, DX=address of parameter area. Returned values vary.
The DOS Plus system variables contain various system settings.
The parameter area is formed:
pb+0: DB system variable ;0-5
pb+1: DB command ;0 => Read the specified variable into AL
;0FFh => Write data at pb+2 to specified variable.
Variables are:
Number Length Description
0 1 screen width-1
1 1 screen height-1
2 1 page mode - 0 if programs like TYPE should give paged output
3 1 system clock speed in Hz
4 1 temporary file drive, 0 for current or 1-16 for A: to P:
5 5 date and time
DW day count, day 1 is 1/1/78
DB BCD hours
DB BCD minutes
DB BCD seconds
Supported by: CP/M 3 and later.
Entered with C=32h, DE=address of parameter area. Returned values vary.
Under CP/M 3, the BIOS should not be directly called, except possibly the character I/O and
USERF calls. Instead, this function should be used. The parameter
area is formed:
pb+0: DB bios-function ;0-32
pb+1: DB bios-a ;Value for A register
pb+2: DB bios-c ;Value for C register
pb+3: DB bios-b ;Value for B register
pb+4: DB bios-e ;Value for E register
pb+5: DB bios-d ;Value for D register
pb+6: DB bios-l ;Value for L register
pb+7: DB bios-h ;Value for H register
Under DOS Plus or CP/M-86, this function should be used for all BIOS calls; only character
I/O BIOS calls are permitted.
Supported by: CP/M-86, DOS Plus.
Entered with CL=33h, DX=segment value.
Supported by: DOS Plus.
Entered with CL=34h. Returns address in ES:BX.
Supported by: DOS Plus.
Entered with CL=35h, DX=address of MCB
Set MCB_EXT to 2 if the memory should remain allocated after program
termination. Set MCB_LENGTH to maximum required length.
Returns MCB_EXT=0 if no additional memory is available, 1 if there is. Sets MCB_SEGMENT
and MCB_LENGTH to the values for the memory block allocated, which will be less than or
equal to the size requested.
Returns AX=0 if OK, 0FFFFh if error; CX=error code:
0 OK
2 Illegal call number
3 Out of memory
12 Out of descriptors
43 Bad Parameter
Supported by: DOS Plus.
Entered with CL=36h, DX=address of MCB
Set MCB_EXT to 2 if the memory should remain allocated after program
termination. Set MCB_LENGTH to maximum required length, and MCB_SEGMENT to
the required start paragraph.
Returns MCB_EXT=0 if no additional memory is available, 1 if there is. Sets MCB_SEGMENT
and MCB_LENGTH to the values for the memory block allocated, which will be less than or
equal to the size requested.
Returns AX=0 if OK, 0FFFFh if error; CX=error code.
Supported by: DOS Plus.
Entered with CL=37h, DX=address of MCB
Set MCB_EXT to 2 if the memory should remain allocated after program
termination. Set MCB_LENGTH to maximum required length.
Returns MCB_EXT=0 if no additional memory is available, 1 if there is. Sets MCB_SEGMENT
and MCB_LENGTH to the values for the memory block allocated, which will be exactly the size
requested.
Returns AX=0 if OK, 0FFFFh if error; CX=error code.
Supported by: DOS Plus.
Entered with CL=38h, DX=address of MCB
Set MCB_EXT to 2 if the memory should remain allocated after program
termination. Set MCB_LENGTH to maximum required length, and MCB_SEGMENT to
the required start paragraph.
Returns MCB_EXT=0 if no additional memory is available, 1 if there is. Sets MCB_SEGMENT
and MCB_LENGTH to the values for the memory block allocated, which will be exactly
the size requested.
Returns AX=0 if OK, 0FFFFh if error; CX=error code.
Supported by: DOS Plus.
Entered with CL=39h, DX=address of MCB
Set MCB_SEGMENT to start of area, MCB_LENGTH to length. It is not possible to
deallocate the middle or start of an area which was allocated as one piece.
Set MCB_EXT to 0 to free the specified MCB, or 0FFh to free all this program's memory.
Returns AX=0 if OK, 0FFFFh if error; CX=error code.
Supported by: DOS Plus, CP/M-86.
Entered with CL=3Ah.
This function is obsolete in DOS Plus.
Supported by: CP/M 3 and higher Loaders.
Entered with C=3Bh, DE=FCB address. Returns error code in A.
Load a program or RSX. The FCB should have been opened before making this call; the
load address should be stored at FCB+21h. If the program is a PRL (Paged Relocatable),
the original CP/M loader will relocate it; some replacement loaders, such as that
in CCP+ need a special flag set to indicate this.
If DE=0, the Loader will not load anything, but it will remove from the RSX chain any
RSXs marked as due for deletion.
Returns A=0 if OK, 0FEh if there was an error, or 0FFh if the Loader is not present.
Supported by: CP/M 3 and later RSXs.
Entered with C=3Ch, DE=RSXPB address
This call is provided for programs to communicate with Resident System Extensions.
The format of the RSXPB is:
DEFB function, 0-127 ;(128-255 used internally by CP/M)
DEFB numwords ;Number of parameter words passed to RSX.
DEFW parameters
A popular convention is for the first parameter word to point to a copy within the
program of the name of the intended RSX; for example:
RSXPB: DEFB 100 ;Function
DEFB 1 ;1 Parameter
DEFW RNAME ;RSX name
RNAME: DEFB 'GETERL '
This call returns BA=HL=00FFh if the requested RSX is not resident; otherwise, the
values are those returned by the RSX.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/Net.
Supported by: CP/M 3.
Entered with C=62h. Returns A=0 if OK, 0FFh if current drive is invalid
This function is called by the CCP when a program terminates. Open files are closed;
buffered data are not written, so files opened for writing may be destroyed if not
properly closed.
Supported by: CP/M 3 and later.
Entered with C=63h, DE=FCB address. Returns error codes in BA and HL.
Set the random record count of the FCB to the required file size in records.
If the file is password protected, point the DMA address at the password.
Returns A=0-3 for success, 0FFh for failure; H may contain a
hardware error code.
Supported by: CP/M 3 and later.
Entered with C=64h, DE=FCB. Returns error codes in BA and HL.
The EX byte (FCB+0Ch) of the FCB should contain a flags byte:
Bit Meaning if set
----------------------------------------
7 Passwords enabled
6 Stamp on access
5 Stamp on update
4 Stamp on creation
0 Assign password at DMA+8 to label.
This function may need a password at the DMA address, if there
is a label on the disc which has a password.
This function returns A=0 if OK, 0FFh for failure. H may contain a
hardware error code.
Supported by: CP/M 3 and later.
Entered with C=65h, E=drive. Returns A=byte
The byte returned has the following bits set:
Bit Meaning if set
----------------------------------------
7 Passwords enabled
6 Stamp on access
5 Stamp on update
4 Stamp on creation
0 Directory label exists
If bit 0 is zero, the other bits are meaningless.
If a label does exist, it can be found using functions 17 and
18 with the first 13 bytes of the FCB set to "?", and checking
for a file whose user number is 32.
Supported by: CP/M 3 and later.
Entered with C=66h, DE=FCB address. Returns error codes in BA and HL.
Gets the file date and time stamps, and the password mode. The stamps end up
at FCB+18h (create or access), FCB+1Ch (update); the password mode ends up at
FCB+0Ch. This returns A=0-3 for success, or 0FFh for failure. To tell whether a
stamp is for creation or access, check the directory label byte.
For information on the format of date and time stamps, see the date and
time calls. The password mode is documented in the next function.
Supported by: CP/M 3 and later.
Entered with C=67h, DE=FCB address. Returns error codes in BA and HL.
Sets file password and protection mode. Set FCB+0Ch to the required password
mode, and point the DMA address at the current password. The password
mode byte should have the following bits set:
Bit Meaning if set
----------------------------------------
7 Reading requires password
6 Writing requires password
5 Deletion requires password
0 Assign password at DMA+8 to file.
Supported by: CP/M 3 and later; some CP/M 2 upgrades.
Entered with C=68h, DE=address of time stamp.
The format of the time stamp is:
DW day ;Day 1 is 1 January 1978
DB hour ;Packed BCD
DB minute ;Packed BCD
The "seconds" counter will be reset to zero when this function is called.
Supported by: CP/M 3 and later; some CP/M 2 upgrades.
Entered with C=69h, DE=address of time stamp. Returns A=seconds (packed BCD).
The format of the time stamp is:
DW day ;Day 1 is 1 January 1978
DB hour ;Packed BCD
DB minute ;Packed BCD
The "seconds" counter will be returned in A.
Supported by: CP/M 3 and above.
Entered with C=6Ah, DE=address of password.
Sets the default password, used for all file operations requiring passwords when no
password is given explicitly.
Supported by: CP/M 3 and above.
Entered with C=6Bh, DE=address of buffer.
Stores a 6-byte serial number at the address given by DE. Usually this number will be
printable ASCII.
Supported by: CP/M 3 and above.
Entered with C=6Ch, DE=code. Returns HL=code.
If DE=0FFFFh, then the current code is returned in HL. Otherwise, it is set to the
value in DE. Allowable values are:
- 00000h - 0FEFFh
- No fatal error
- 0FF00h - 0FF7Fh
- Fatal error
- 0FF80h - 0FFFCh
- Reserved
- 0FFFDh
- Program terminated because of a hardware error.
- 0FFFEh
- Program terminated by Control-C.
If a program was chained by function 47, an error code
stored by the previous program will be available to it. Otherwise the CCP
sets the return code to zero when it executes a program (some replacement
CCPs do not do this).
If the error code is 0FF00h or above, and the next command begins with the
character : then it will not be run.
Supported by: CP/M 3 and above
Entered with C=6Dh, DE=mode or 0FFFFh. Returns HL=mode.
The mode is a bitmapped value. The significant bits are:
0 If set, function 11 detects only ^C.
1 If set, ^S does not pause screen output.
2 If set, output does not expand tabs, nor is it echoed to the printer even if ^P was
pressed.
3 If set, ^C does not cause the program to terminate.
8 } These form a 2-bit number controlling GET and SUBMIT:
9 }
0 Return "conditional" status to function 11.
Programs using function 11 to test for interruption (eg SID) are not
interrupted, but those using it to test for input do get the input.
1 Function 11 always returns "true".
2 Function 11 always returns "false".
3 Temporarily disable GET/SUBMIT, input comes from keyboard.
Supported by: CP/M 3 and above
Entered with C=6Eh, DE=0FFFFh or ASCII value. Returns ASCII value in A.
This function gets or sets the string delimiter (used in function 9
to mark the end of the string to print). If DE=0FFFFh, this gets the current ASCII value
into A; otherwise it sets the delimiter to the value in E.
Supported by: CP/M 3 and above
Entered with C=6Fh, DE=address of character control block.
For 8-bit CP/M, the character control block is formed:
DW text_begin
DW text_length
For 16-bit CP/M, it is formed:
DW text_begin_offset
DW text_begin_segment
DW text_length
Supported by: CP/M 3 and above
Entered with C=70h, DE=address of character control block.
Format of character control block
Supported by: Personal CP/M.
Supported by: GSX (Graphics System Extension)
Entered with C=73h, DE=parameter block address.
Supported by: DOS Plus
Entered with CL=74h, DX=FCB address. Returns AX=BX=error code.
The required stamps should be put at the DMA address.
Returns AL = 0-3 for success, or 0FFh for failure.
Supported by: Personal CP/M.
Supported by: Personal CP/M.
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M, DOS Plus
Entered with C=8Dh, DE=no. of ticks to wait.
Delays calling process out for DE ticks of the system clock (system dependent;
usually 50Hz or 60Hz). Returns A=0FFh if this function is unsupported.
Supported by: MP/M, Concurrent CP/M, DOS Plus
Entered with C=8Eh.
Relinquishes the CPU. The process restarts when its next time slice falls due.
Returns A=0FFh if this function is unsupported.
Supported by: MP/M, Concurrent CP/M, DOS Plus
Entered with C=8Fh.
As function 0.
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Entered with C=92h.
Blocks the calling process until the system console is available. This is
automatically called if any console I/O function is used while the current
process is not attached to the console.
Supported by: MP/M, Concurrent CP/M, DOS Plus
Entered with C=93h.
The program is disconnected from the screen and keyboard and must run in the background.
Under DOS Plus, attempting to use the keyboard will cause the program to be
terminated. Note that backgrounded programs cannot use the INT 2nh
DOS-like calls, only the INT E0h CP/M calls. Limited screen output can
be achieved using BIOS function 8 (write to status line).
Under MP/M and CCP/M, attempting to output to the screen will cause function
146 to be invoked.
Supported by: MP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, CP/M 3 and higher.
Entered with C=98h, DE=address of PFCB. Returns codes in HL.
This parses an ASCII filename to a FCB. The format of the PFCB is:
DEFW ascii-address
DEFW fcb-address
The value returned in HL is 0FFFFh if the ASCII filename was invalid; 0 if
the ASCII filename was terminated with a zero or a carriage return;
and otherwise the address of the next character after the filename.
The filename can be of any form up to the full d:filename.typ;password
(password only under CP/M 3 and above). When the filename is parsed, the password
is copied to FCB+10h, with its length at FCB+1Ah.
Under ZPM3, the filename may be of the form du:filename.typ;password; FCB+0Dh
will be 0 if no user number was specified, or 1+number otherwise. If a Z-System is loaded,
ZPM3 can also parse filenames of the form dir:filename.typ;password.
BUG: ZPM3 (version N10) puts the password at FCB+0Ch rather than FCB+10h,
overwriting the user number stored at FCB+0Dh.
The filename can be terminated by any of:
space tab cr nul ; = > < . : , [ ] / | .
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M, Concurrent CP/M, DOS Plus
Entered with C=9Ah. Returns HL (or ES:BX) = system data address.
Supported by: MP/M, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Entered with C=9Eh.
Blocks the calling process until the default printer is available. This is
automatically called if any printer function is used while the current
process is not attached to the printer.
Supported by: MP/M 2, Concurrent CP/M
Entered with C=9Fh.
Detach this process from the printer,
Supported by: MP/M 2, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Supported by: MP/M 2, Concurrent CP/M
Supported by: DOS+
Entered with C=0D2h, E=number, 0-5. Returns values in BA and HL.
Suitable arguments are:
0. Return base address for BDOS module. Used for dynamic reconfiguration.
1. Return the current DMA setting.
2. Flush any console input pending, emptying all buffers. Returns 0.
3. Returns list device status (ready/not ready)
4. Returns punch " " "
5. Returns reader " " "
Arguments 3 thru 5 represent ready as 0ffh, not ready as 0. If no custom
installation for punch/reader device status has been made their status
is returned 0 (not ready). Other arguments return 0.
Supported by: DOS+
Entered with C=0D3h, DE=decimal number.
Outputs the number as an unsigned 16-bit integer, with leading zero
suppression.
