GEMDOS.TXT
INCOMPLETE CHECK FRENCH VERSION
***-------------- FUNCTIONS GEMDOS BY NUMBER ---------------***
$00 Pterm0 Terminate process
$01 Cconin Read a character from standard input
$02 Cconout Write a character to standard output
$03 Cauxin Read a character from AUX: standard input
$04 Cauxout Write a character to AUX: standard output
$05 Cprnout Write a character to PRN: standard output
$06 Crawio Raw input/output on standard input/output
$07 Crawcin Raw input on standard input
$08 Cnecin Read a character from standard input without echo
$09 Cconws Write a string to standard output
$0A Cconrs Read a formatted string from standard input
$0B Cconis Test standard input status
$0E Dsetdrv Set default disk drive
$10 Cconos Test standard output status
$11 Cprnos Test PRN: standard output status
$12 Cauxis Test AUX: standard input status
$13 Cauxos Test AUX: standard output status
$19 Dgetdrv Get default disk drive
$1A Fsetdta Set Disk Transfer Address (DTA) address
$20 Super Enter/Exit/Inquire Supervisor mode
$2A Tgetdate Inquire date
$2B Tsetdate Set date
$2C Tgettime Inquire time
$2D Tsettime Set time
$2F Fgetdta Inquire Disk Transfer Address (DTA) address
$30 Sversion Inquire GEMDOS version number
$31 Ptermres Terminate resident program
$36 Dfree Inquire free space on a disk
$39 Dcreate Create a subdirectory
$3A Ddelete Delete a subdirectory
$3B Dsetpath Set current directory
$3C Fcreate Create a file
$3D Fopen Open a file
$3E Fclose Close a file
$3F Fread Read from a file
$40 Fwrite Write to a file
$41 Fdelete Delete a file
$42 Fseek Set file position
$43 Fattrib Inquire/Set file attributes
$45 Fdup Duplicate file handle id
$46 Fforce Force file handle
$47 Dgetpath Inquire current directory
$48 Malloc Allocate memory
$49 Mfree Free memory
$4A Mshrink Shrink allocated memory block
$4B Pexec Load/Execute a program
$4C Pterm Terminate a program
$4E Fsfirst Search for the first occurrence of a file
$4F Fsnext Search for the next occurrence
$56 Frename Rename a file
$57 Fdatime Set/Inquire file creation date and time
***-------------- GEMDOS FUNCTIONS BY NAME ----------------------***
$03 Cauxin Read a character from AUX: standard input
$12 Cauxis Test AUX: standard input status
$13 Cauxos Test AUX: standard output status
$04 Cauxout Write a character to AUX: standard output
$01 Cconin Read a character from standard input
$0B Cconis Test standard input status
$10 Cconos Test standard output status
$02 Cconout Write a character to standard output
$0A Cconrs Read a formatted string from standard input
$09 Cconws Write a string to standard output
$08 Cnecin Read a character from standard input without echo
$11 Cprnos Test PRN: standard output status
$05 Cprnout Write a character to PRN: standard output
$07 Crawcin Raw input on standard input
$06 Crawio Raw input/output on standard input/output
$39 Dcreate Create a subdirectory
$3A Ddelete Delete a subdirectory
$36 Dfree Inquire free space on a disk
$19 Dgetdrv Get default disk drive
$47 Dgetpath Inquire current directory
$0E Dsetdrv Set default disk drive
$3B Dsetpath Set current directory
$43 Fattrib Inquire/Set file attributes
$3E Fclose Close a file
$3C Fcreate Create a file
$57 Fdatime Set/Inquire file creation date and time
$41 Fdelete Delete a file
$45 Fdup Duplicate file handle id
$46 Fforce Force file handle
$2F Fgetdta Inquire Disk Transfer Address (DTA) address
$3D Fopen Open a file
$3F Fread Read from a file
$56 Frename Rename a file
$42 Fseek Set file position
$1A Fsetdta Set Disk Transfer Address (DTA) address
$4E Fsfirst Search for the first occurrence of a file
$4F Fnext Search for the next occurrence
$40 Fwrite Write to a file
$48 Malloc Allocate memory
$49 Mfree Free memory
$4A Mshrink Shrink allocated memory block
$4B Pexec Load/Execute a program
$4C Pterm Terminate a program
$00 Pterm0 Terminate a program (return code 0)
$31 Ptermres Terminate a resident program
$20 Super Enter/Exit/Inquire Supervisor mode
$30 Sversion Inquire GEMDOS version number
$2A Tgetdate Inquire date
$2C Tgettime Inquire time
$2B Tsetdate Set date
$2D Tsettime Set time
*------------------------------------------------------------------*
$00 Pterm0 Terminate a program
void Pterm0()
Terminate a process, closing all files it has opened and releasing
the memory it has allocated. Returns $0000 as the exit code to the
parent program.
*------------------------------------------------------------------*
$01 Cconin Read a character from standard input
LONG Cconin()
Read a character from standard input (identifier 0). If the standard
input is the console, the long word returned in D0 contains the ASCII
code and the keyboard code of the pressed key (scan code):
________________________________________________
| 31..24 | 23.. 16 | 15..8 | 7..0 |
|-------------|-----------|----------|-----------|
| | scan code| $00 | character |
| $00 or bits | or $00 | | ASCII |
| of shift | or $00 | | |
|_____________|___________|__________|___________|
Function keys (F1 to F10, HELP, UNDO, etc...) return ASCII code $00
with the appropriate keyboard code (see the intelligent keyboard
manual for the key codes). The ST BIOS places the state of special
keys in bits 24 to 31 (see the ST BIOS programmer's guide for more
details).
ERRORS
Does not return any indication of end of file.
Does not recognize 'Control_C'
Impossible to know if the input is a character device or a file.
There should be a way to type the 256 possible codes from the
keyboard.
*------------------------------------------------------------------*
$02 Cconout Write a character to the standard output
void Cconout(c)
WORD c
Write the character 'c' to the standard output (identifier 0).
The eight most significant bits of 'c' are reserved and must be zero.
Tabs are not interpreted.
*------------------------------------------------------------------*
$03 Cauxin Read a character from AUX: standard input
WORD Cauxin()
Read a character from identifier 1 (the AUX: serial port, usually).
NOTE
Output flow control of the RS232 does not work with this
function. Programs should use the BIOS character device call
to avoid losing received characters.
*------------------------------------------------------------------*
$04 Cauxout Write a character to the AUX: standard output
void Cauxout(c)
WORD c
*------------------------------------------------------------------*
$05 Cprnout Write a character to the PRN: standard output
void Cprnout(c)
WORD c
Write 'c' to identifier 2 (the PRN: printer port, usually). The high
bits of 'c' are reserved and must be zero. Tabs are not interpreted.
*------------------------------------------------------------------*
$06 Crawio Raw input/output on standard input/output
LONG Crawio(w)
WORD w;
NOTES
By its very design this function cannot write '$ff' to the
standard output.
$00 cannot be differentiated from an end of file.
*------------------------------------------------------------------*
$07 Crawcin Raw input on standard input
LONG Crawcin()
NOTE No end of file indication.
*------------------------------------------------------------------*
$08 Cnecin Read a character from standard input without echo
LONG Cnecin()
Read a character from standard input. If the input device is 'CON:',
no echo is made. Control characters are interpreted.
*------------------------------------------------------------------*
$09 Cconws Write a string to standard output
void Cconws(string)
char *string;
Write a string starting from 'string' and ending with 0, to the
standard output.
*------------------------------------------------------------------*
$0A Cconrs Read a formatted string from standard input
void Cconrs(buf)
char *buf
Read a string from standard input. The usual control characters are
interpreted:
____________________________________________
| Character | Function |
|-------------|-----------------------------|
| <return>, ^J | End of line |
| ^H, <rub> | Erase last character |
| ^U, ^X | Erase entire line |
| ^R | Recopy line |
| ^C | End program |
|______________|_____________________________|
The first character of 'buf' contains the maximum number of bytes to
read (buffer size minus two). On output, the second byte contains
the number of characters read. The string is located between 'buf+2'
and 'buf+2+buf[1]'. It is not guaranteed that the string ends with 0.
NOTE Crashes on end of files.
*------------------------------------------------------------------*
$0B Cconis Test standard input status
WORD Cconis()
Returns $FFFF if a character is available on standard input, $0000
otherwise.
*------------------------------------------------------------------*
$0E Dsetdrv Set default disk drive
LONG Dsetdrv(drv)
WORD drv;
Set disk 'drv' as the default. Drives are numbered 0 to 15 (A: to P:).
Returns in D0.L the bitmap of active drives:
(bit 0 = A, bit 1 = B, etc..).
An 'active drive' is a drive from which a directory has been made.
NOTE GEMDOS only supports 16 drives (bits 0 to 15). Future systems will
support 32 .
*------------------------------------------------------------------*
$10 Cconos Test standard output status
WORD Cconos()
Returns $FFFF if the console is ready to receive a character,
$0000 if the console is NOT ready.
*------------------------------------------------------------------*
$11 Cprnos Test PRN: standard output status
WORD Cprnos()
Returns $FFFF if 'PRN:' is ready to receive a character, $0000
otherwise.
*------------------------------------------------------------------*
$12 Cauxis Test AUX: standard input status
WORD Cauxis()
Returns $FFFF if a character is available on 'AUX:' input (identifier 1),
$0000 otherwise.
*------------------------------------------------------------------*
$13 Cauxos Test AUX: standard output status
WORD Cauxos()
Returns $FFFF if 'AUX:' (identifier 1) is ready to receive a
character, $0000 otherwise.
*------------------------------------------------------------------*
$19 Dgetdrv Get default disk drive
WORD Dgetdrv()
Returns the number of the current drive, ranging from 0 to 15.
*------------------------------------------------------------------*
$1A Fsetdta Set Disk Transfer Address (DTA) address
void Fsetdta(adr)
char adr;
Sets the DTA address to 'adr'. The data storage buffer on a file (DTA)
is only used by the functions Fsfirst() and Fsnext().
*------------------------------------------------------------------*
$20 Super Enter/Exit/Inquire Supervisor mode
LONG Super(stack)
WORD *stack;
'stack' is equal to -1L ($FFFFFFFF):
the function returns $0000 if the processor is in User mode, $0001 if
it is in Supervisor mode.
'stack' is different from -1L:
if the processor is in User mode, the function returns
to Supervisor mode. If 'stack' is NUL ($00000000), the
supervisor stack will be the same as the user stack before
the call. Otherwise the supervisor stack will be placed at 'stack'.
if the processor was in Supervisor mode, it returns
to User mode after the function call. 'stack' must be the value
of the user stack that was returned by the first function call.
ATTENTION
The original Supervisor stack must be replaced before the end
of the program, otherwise the system will crash on program exit.
*------------------------------------------------------------------*
$2A Tgetdate Inquire date
WORD Tgetdate()
Returns the date in DOS format:
15 __________________9_8_________5_4_________0
| Years since 1980 | month | day |
| 0.....119 | 1...12 | 1...31 |
|____________________|___________|___________|
RETURN
bits 0 to 4 contain the day from 1 to 31.
bits 5 to 8 contain the month from 1 to 12.
bits 9 to 15 contain the year (from 1980 onward)
ranging from 0 to 119.
*------------------------------------------------------------------*
$2B Tsetdate Set date
WORD Tsetdate(date)
WORD date;
Set 'date' as the current date in the format described in
Tgetdate().
RETURN 0 if the date is valid.
ERROR if the date format is incorrect.
NOTE
GEMDOS is not picky about the date; for instance, February 31 does
not bother it.
GEMDOS does NOT notify BIOS that the date has changed.
*------------------------------------------------------------------*
$2C Tgettime Inquire time
WORD Tgettime()
Returns the current time in DOS format:
15__________11_10________5_4__________0
| hour | minute | second |
| 0...23 | 0...59 | 0...28 |
|______________|___________|____________|
RETURN Bits :
0 to 4 contain the seconds divided by 2 (0 to 28)
5 to 10 contain the minutes (0 to 59)
11 to 15 contain the hours (0 to 23)
*------------------------------------------------------------------*
$2D Tsettime Set time
WORD Tsettime(time)
WORD time;
Set 'time' as the current time in the format described in
Tgettime().
RETURN 0 if the provided time format is valid;
ERROR if the time format is invalid.
NOTE
GEMDOS does not notify BIOS that the time has changed.
*------------------------------------------------------------------*
$2F Fgetdta Inquire Disk Transfer Address (DTA) address
LONG Fgetdta()
Returns the current address of the data storage buffer on a file
(DTA), used by the functions Fsfirst() and Fsnext().
*------------------------------------------------------------------*
$30 Sversion Inquire GEMDOS version number
WORD Sversion()
Returns the GEMDOS version number in reverse format. The most
significant byte contains the low part of the number, the least
significant byte, the high part.
NOTE
The GEMDOS version on the 5/29/85 diskette and the first
ROM version on 11/20/85 have $1300 as the number.
The GEMDOS and TOS version numbers are NOT the same. (see
the ST BIOS reference manual for the TOS version number).
*------------------------------------------------------------------*
$31 Ptermres Terminate a resident program
void Permres( rest,retcode)
LONG rest;
WORD retcode;
Ends the current program, preserving some of its memory.
'rest' is the number of bytes belonging to the program that
should be kept, including and starting at the base page.
'retcode' is the exit code returned to the parent program.
The memory that the program has allocated (in addition to its TPA
zone) is NOT freed.
It is impossible to recall the program terminated by Ptermres().
NOTE
Open files are closed when the process ends.
*------------------------------------------------------------------*
$36 Dfree Requests free space on a disk
void Dfree(buf,nbdisq)
LONG *buf;
WORD nbdisq;
Requests information about the disk 'nbdisq' and places it in
four long words starting at 'buf':
__________________________________________________
| buf + 0 | number of free blocks on the disk |
|-----------|--------------------------------------|
| buf + 4 | total number of blocks on the disk |
|-----------|--------------------------------------|
| buf + 8 | size of a sector in bytes |
|-----------|--------------------------------------|
| buf + 12 | number of sectors per block |
|___________|______________________________________|
NOTE Incredibly slow on a hard disk (5 to 10 seconds).
*------------------------------------------------------------------*
$39 Dcreate Creation of a subdirectory on disk C
WORD Dcreate(path)
char *path;
'Path' points to a 0-terminated string specifying the path
of the new directory.
RETURN
0 if successful;
ERROR or the appropriate error number in case of failure.
*------------------------------------------------------------------*
$3A Ddelete Deletes a subdirectory
WORD Ddelete(path)
char *path;
Deletes a directory that must be empty (it can, however,
contain the special files "." and ".."). 'Path' points to
a 0-terminated string specifying the path of the directory to
delete.
RETURN 0 if successful;
ERROR or the appropriate error number in case of failure.
*------------------------------------------------------------------*
$3B Dsetpath Sets the current directory
WORD Dsetpath(path)
char *path;
Sets 'path', (a 0-terminated string), as the current directory.
If the path starts with a drive letter followed by a colon, the current directory is set to the specified drive.
The system maintains a current directory for each drive.
RETURN 0 if successful;
ERROR or the appropriate error number in case of failure.
*------------------------------------------------------------------*
$3C Fcreate Creation of a file
WORD Fcreate(filename,attribs)
char *filename;
WORD attribs;
Creates a file 'filename' and returns its non-standard,
write-only identifier. The attribute word is stored in the
directory; the attribute bits are:
_________________________________________________________
| mask | description |
|--------|-----------------------------------------------|
| $01 | file created read-only |
| $02 | file transparent to directory |
| $04 | system file |
| $08 | file containing a volume name on 11 bits |
|________|_______________________________________________|
RETURN
A positive number, the identifier or :
ERROR or the appropriate error number.
NOTES
If the read-only bit is set, a write-only identifier
is returned, and moreover, this identifier does not
allow writing.
Theoretically, only one volume number is allowed on a
root directory. GEMDOS does not enforce this, which
can cause some confusion.
*------------------------------------------------------------------*
$3D Fopen Opening a file
WORD Fopen(filename,mode)
char *filename;
WORD mode;
Opens the file 'filename' in mode 'mode' and returns its non-
standard identifier. The opening mode can be:
____________________________
| mode | description |
|-------|---------------------|
| 0 | read-only |
| 1 | write-only |
| 2 | read and write |
|_______|_____________________|
RETURN
A positive number, the identifier
A negative error number.
*------------------------------------------------------------------*
$3E Fclose Closing a file
WORD Fclose(fileid)
WORD fileid;
Closes the file with the identifier 'fileid'.
RETURN 0 if successful;
ERROR or an appropriate error number in case of failure.
*------------------------------------------------------------------*
$3F Fread Reading from a file
LONG Fread(fileid,nbre,buffer)
WORD fileid;
LONG nbre;
char *buffer;
Reads 'nbre' bytes from the file with identifier 'fileid', and
places them in memory starting from the address 'buffer'.
RETURN
The number of bytes actually read, or:
0 if end of file code,
A negative error number.
*------------------------------------------------------------------*
$40 Fwrite Writing to a file
LONG Fwrite(fileid,nbre,buffer)
WORD fileid;
LONG nbre;
char *buffer;
Writes 'nbre' bytes from memory starting from the address 'buffer',
into the file with identifier 'fileid'.
RETURN The number of bytes actually written if successful.
A negative error number otherwise.
*------------------------------------------------------------------*
$41 Fdelete Deleting a file
WORD Fdelete(filename)
char *filename;
Deletes the file named 'filename'.
RETURN 0 if successful
A negative error number otherwise.
*------------------------------------------------------------------*
$42 Fseek Positioning the file pointer
LONG Fseek(offset,fileid,mode)
LONG offset;
WORD fileid;
WORD mode;
Positions the pointer in the file defined by the identifier
'fileid'. 'Offset' is a signed number; a positive value
moves the pointer towards the end of the file, a negative value
towards the beginning. The positioning mode can be:
_____________________________________________
| mode | Move offset bytes... |
|--------|------------------------------------|
| 0 | from the beginning of the file |
| 1 | from the current position |
| 2 | from the end of the file |
|________|____________________________________|
RETURN The current position in the file.
A negative error number if error.
*------------------------------------------------------------------*
$43 Fattrib Set or request file attributes
WORD Fattrib(filename,flag,attribs)
char *filename;
WORD flag;
WORD attribs;
'Filename' points to a 0-terminated path. If 'flag' is
1, the file attributes 'attribs' are set (no return value).
If 'flag' is 0, they are returned.
The attribute bits are:
_________________________________________________________
| mask | description |
|--------|------------------------------------------------|
| $01 | read-only file |
| $02 | file transparent to directory |
| $04 | 'system' file |
| $08 | file containing a volume name (11 bytes) |
| $10 | file subdirectory |
| $20 | file written and then closed |
|________|________________________________________________|
NOTE The archive bit, $20, does not seem to work as
expected.
*------------------------------------------------------------------*
$45 Fdup Duplicates a file identifier
WORD Fdup(fileid)
WORD fileid;
The identifier 'fileid' must be a standard identifier (0 to
5). Fdup() returns a non-standard identifier (6 or higher) that points to the same file.
RETURN An identifier or :
EIHNDL 'fileid' is not a standard identifier
ENHNDL No more non-standard identifiers
*------------------------------------------------------------------*
$46 Fforce Force a file identifier
Fforce(stdh,nonstdh)
WORD stdh;
WORD nonstdh;
Forces the standard identifier 'stdh' to point to the same file
or device as the non-standard identifier 'nonstdh'.
RETURN 0 if OK
EIHNDL invalid identifier.
*------------------------------------------------------------------*
$47 Dgetpath Requests the current directory
void Dgetpath(buf,driveno)
char *buf;
WORD driveno;
The current directory for the drive 'driveno' is copied into
'buf'. The drive number starts at 1 for drive A:, 2
for drive B:, etc..., 0 specifying the default disk.
NOTE
The maximum size of a path is not limited by the system.
It is up to the application to provide enough space for the
buffer. 128 bytes seem sufficient for 8 or 9 subdirectories.
*------------------------------------------------------------------*
$48 Malloc Memory allocation request
LONG Malloc(size)
LONG size;
If 'size' is -1L ($FFFFFFFF) the function returns the size of the
largest free block in the system. Otherwise if 'size' is
different from -1L, the function tries to allocate 'size' bytes for
the current program. The function returns a pointer to the
beginning of the allocated block if all went well, or NULL if there
was no block large enough to satisfy the request.
NOTE
A program can have, at any given time, no more than 20 blocks
allocated by 'Malloc()'. Exceeding this limit can disrupt GEMDOS.
(However, it is possible to make as many 'Malloc()' calls as
desired as long as they are followed by the call of the
'Mfree()' function, 20 being the maximum number of
Back to ASM_Tutorial