Original NCIOSPEC.TXT follows:
The following notes describe the low level operation of the Amstrad Notepad
computers. They are intended for third party developers who want to program
the Notepad in machine code.
As always, I will try to help out if anyone has questions about this but I
cannot give an absolute guarantee to be able to provide support on the low
level operation of the machine.
It is our intention that these firmware routines and system variables should
be maintained in future issues of the software but we cannot give an absolute
guarantee about this.
Cliff Lawson CIS: 75300,1517
Notepad project manager email: cliffl@amstrad.com
Amstrad Plc amstrad@cix.compulink.co.uk
169 Kings Road Phone: (+44) 277 208341
Brentwood Fax: (+44) 277 208065
Essex
CM14 4EF
ENGLAND
I/O Specification for Amstrad NC100
All numbers are in hexadecimal unless suffixed with a "b" for binary or
"d" for decimal. (Address line numbers A19, A18, etc are in decimal).
SUMMARY
Address Comment R/W
E0-FF Not Used -
D0-DF RTC (TC8521) R/W
C0-C1 UART (uPD71051) R/W
B0-B9 Key data in R
A0 Card Status etc. R
90 IRQ request status R/W
80-8F Not Used
70 Power on/off control W
60 IRQ Mask W
50-53 Speaker frequency W
40 Parallel port data W
30 Baud rate etc. W
20 Card wiat control W
10-13 Memory management R/W
00 Display memory start W
In Detail
Address = 00 Write only
start address of display memory
bit 7 A15
bit 6 A14
bit 5 A13
bit 4 A12
bits 3-0 Not Used
On reset this is set to 0.
The display memory for the 8 line NC computers consists of a block of 4096
bytes where the first byte defines the state of the pixels in the top left
hand corner of the screen. A 1 bit set means the pixel is set to black. The
first byte controls the first 8 dots with bit 7 controlling the bit on the
left. The next 59 bytes complete the first raster line of 480 dots. The bytes
which define the second raster line start at byte 64 to make the hardware
simpler so bytes 60, 61, 62 and 63 are wasted. There are then another 64 bytes
(with the last 4 unused) which defines the second raster line and so on
straight down the screen. That is (all numbers decimal):
byte00 byte01 byte02 byte59 byte60 byte63
Bit Number 76543210 76543210 76543210 .. 76543210 76543210.. 76543210
Pixel Number 01234567 89012345 67890123 .. 23456789 wasted .. wasted
(read bottom 00000000 00111111 11112222 77777777
to top decimal) 00000000 00000000 00000000 44444444
....and so on for subsequent lines. (Second line = bytes 64..127 etc.)
Address = 10..13 Read/Write
Memory management control
10 controls 0000-3FFF
11 controls 4000-7FFF
12 controls 8000-BFFF
13 controls C000-FFFF
On reset all are set to 0.
For each address the byte written has the following meaning:
bit 7 together they select ROM, internal RAM, card RAM
bit 6 00b = ROM
01b = internal RAM
10b = card RAM
bits 5-0 determine address lines 19 to 14.
Therefore, 00 is the first 16K of ROM, 01 is the second 16K, etc.
40 is the first 16K of internal RAM, 41=second 16K, etc.
80 is the first 16K of card RAM, 81=second 16K, etc.
So, for example, if you want to switch the third 16K of internal RAM so the
processor sees it at 4000-7FFF you would output the value 42 to I/O address
11. 42 has bits 7,6 = 01b and bits 5-0 are 00010b which is the third 16K of
internal RAM.
Address = 20 Write only
Memory card wait state control
bit 7 = 1 for wait states, 0 for no wait
On reset this is set to 1. The bit should be set if the card RAM/ROM is
200nS or slower.
Address = 30 Write only
Baud rate etc.
bit 7 select card register 1=common, 0=attribute
bit 6 parallel interface Strobe signal
bit 5 Not Used
bit 4 uPD4711 line driver, 1=off, 0=on
bit 3 UART clock and reset, 1=off, 0=on
bits 2-0 set the baud rate as follows
000 = 150
001 = 300
010 = 600
011 = 1200
100 = 2400
101 = 4800
110 = 9600
111 = 19200
On reset all data is set to 1.
If programming the UART directly ensure that TxD clock is operating x16.
Address = 40 Write only
Parallel interface data
The byte written here is latched into the parallel port output register. To
print it you must then take the Strobe signal (I/O address 30 bit 6) low and
then high again. If the printer sends ACK this may generate an IRQ if the mask
bit is set in I/O address 60 - IRQ mask.
Address = 50..53 Write only
Sound channels period control
50 channel A period low
51 channel A period high
52 channel B period low
53 channel B period high
On reset all data is set to FF. The top bit in the high byte (51 and 53)
switches the resepective sound generator on or off - 1=off, 0=on.
The frequency generated is determined as:
Frequency = 1,000,000d
----------
data * 2 * 1.6276
So if the data word programmed into 50 and 51 was 7800 (ie 50=0, 51=78) then
the frequency generated would be:
freq = 1,000,000 = 1,000,000 = 1,000,000 = 10Hz
--------- --------- ---------
7800h * 2 * 1.6276 30720 * 2 * 1.6276 99,999.7
Address = 60 Write only
Interrupt request mask
bits 7-4 Not Used
bit 3 Key Scan interrupt (every 10mS)
bit 2 ACK from parallel interface
bit 1 Tx Ready from UART
bit 0 Rx Ready from UART
On reset all bits are 0. For each bit, 1=allow that interrupt source to
produce IRQs. 0 = interrupt source is masked.
Address = 70 Write only
Power off control
bits 7-1 Not Used
bit 0 1 = no effect, 0 = power off
On reset this is set to 1.
Address = 90 Read/Write
IRQ status
bits 7-4 Not Used
bit 3 Key scan
bit 2 ACK from parallel interface
bit 1 Tx Ready interrupt
bit 0 Rx Ready interrupt
When an interrupt occurs this port should be read to determine the source of
the interrupt. The bit will be set to 0 to identify the interrupting device.
The interrupt can then be cleared by writing 0 to that bit.
Address = A0 Read only
Memory card/battery status
bit 7 Memory card present 0 = yes, 1 = no
bit 6 Card write protected 1 = yes, 0 = no
bit 5 Input voltage = 1 if >= to 4 Volts
bit 4 Mem card battery. 0 = battery is low
bit 3 Alkaline batteries. 0 if >= 3.2 Volts
bit 2 Lithium battery. 0 if >= 2.7 Volts
bit 1 Parallel interface BUSY (0 if busy)
bit 0 Parallel interface ACK (1 if ACK)
Address = B0 - B9 Read only
Keyboard data
B0..B9 each key of the 64 on the keyboard
will set a bit in one of these bytes
while pressed.
The gate array scans the keyboard every 10mS and then generates an
interrupt. The program should then read these 10 I/O locations to
determine which key(s) is pushed. When I/O address B9 is read the
key scan interrupt is cleared automatically and the next scan cycle
will start from B0.
Address = C0 Read/Write
UART control/data
C0 UART data register
C1 UART status/control register
The UART is the NEC uPD71051. Programmers are advised to study the data
sheet for that chip for more information. The Serial interface requires
that the uPD4711 line driver chip be truned on by writing a 0 to bit 4 of
I/O address 30. While turned on power consumption increases so this should
only be done when necessary.
Address = D0 Read/Write
Real Time Clock chip (TM8521)
D0..DC Data
DD Control register
DE Control register (Write only)
DF Control register (Write only)
See data sheet of chip for more information.
----
NC100 operating system firmware
notes for external program writers
To get external programs executed on the Notepad you could either POKE
them into memory in BBC BASIC (or even use its built-in Z80 assembler)
and then CALL the entry point. However, this does have the drawback of
needing to transfer the code back to the machine each time it crashes
(as it inevitably will).
The simplest way to develop for the Notepad is to get a PCMCIA drive
for your PC and write a binary image direct to the card using that. If
this isn't possible then small programs (up to 16K) can be developed by
transferring the binary card image into the Notepad using Xmodem from
the PC. The use the "Make program card" feature in the File, transfer
menu to write that file onto a newly formatted PCMCIA RAM card.
In either case, to run the resultant code, you just press Function-X
(eXecute) and the first 16K page of the RAM card will be switched to
the Z80 memory map at C000..FFFF. A Check is made that location C200
holds the ASCII text "NC100PRG" and also that locations C210..C212
contains a long jump to C220. All being well, the Z80 starts executing
code at C210 so that, once you have control, you can take over
completely if you wish (driving all hardware functions directly). Most
people will probably want to cooperate with the in built firmware as it
provides most of the routines that one would require anyway.
The ASCII text "NC100PRG" must appear at C200h
program origin is C210h
program MUST start with jp C220h
the program name is at C213h, max 12 characters, zero terminated
org C200h
db "NC100PRG"
org c210h
jp start
db "PROGRAM NAME",0
org C220h
start
available workspace A000h to A3FFh (shared with other programs)
also A800h to AFFFh (this is overwritten if selectfile is called)
the program MUST handle yellow events :-
either exit when Stop is pressed
or check for yellow event with kmgetyellow and return if carry set
Serious developers may be interested in contacting Ranger Computers Ltd
on (+44) 604 589200 as they can produce a device that looks like RAM to
a PC but ends in a PCMCIA header plug that connects directly to the
Notepad's card slot and the "PC RAM" appears as card RAM to the Notepad.
The following sequence is a working(!) piece of code written for the
AVMACZ80 assembler on a PC, which, when assmembled produces a binary
file that can be programmed onto a PCMCIA card and executed. The
program just reads keys and prints them back until "Q" is pressed.
Notice that exit from the program is just by a RET back to the
operating system that called it:
;VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
include "nc100jmp.inc" ;The list of firmware routine
;addresses given later in this
;file
DEFSEG Fred, CLASS=CODE, START=0
SEG Fred ;Seg will be linked to RUNSAT C000h
jp start ;put a jump at the start in case this code is
;ever programmed into a ROM page where the entry
;will almost certainly be made at the more
;normal C000.
ds 509 ;waste first 512 bytes of card to start at C200
;
; following 16 bytes are Arnor's header for card at C200
;
db "NC100PRG",0,0,0,0,0,3,0,1
;
; then card program must start with this long jump at C210
;
jp start ;this is at C210h
db "CLIFFS PROG",0,0 ;0's pad to C220h
start:
call kmreadchar
ld a,c
cp "q"
jr z,finish
call txtoutput
jr start
finish:
ret
end
;^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
; code is assembled with:
; AVMACZ80 TEST.ASM
;which produces a .OBJ file which is then linked to produce a .HEX file
;with the command
; AVLINK @TEST.LNK
;where TEST.LNK contains:
; TEST.HEX=TEST.OBJ -RUNSAT(Fred, 0C000h)
;finally the Intel .HEX file is converted to .BIN using a HEX2BIN converter
;The .BIN file is either written to the PCMCIA card using a PC based
;card drive or it can be Xmodemed across to the Notepad and written to
;the card using "Make program card". Finally, Function-X executes it.
In other assemblers you may not have "segments" and must use a direct
ORG to locate code at C000 but watch out for the resultant .HEX file
being padded out with 48K of "0"s from 0000 to BFFF!!
Alphabetic list of routine entry points
=======================================
To use any one of these routines just load the registers as described in
the following and then call the relevant address. Although the running of the
routine may involve a different ROM bank being switched in, this mechanism
is invisble to the caller. So, for example, to print a capital A one might use:
txtoutput EQU B833
LD A,"A"
CALL txtoutput
col1 equ B818h
col1text equ B81Bh
diskservice equ BA5Eh
editbuf equ B800h
fclose equ B890h
fdatestamp equ B8C9h
ferase equ B893h
fgetattr equ B8CFh
finblock equ B896h
finchar equ B899h
findfirst equ B89Ch
findnext equ B89Fh
fnoisy equ B917h
fopenin equ B8A2h
fopenout equ B8A5h
fopenup equ B8A8h
foutblock equ B8ABh
foutchar equ B8AEh
fquiet equ B91Ah
frename equ B8B1h
fseek equ B8B4h
fsetattr equ B8CCh
fsize equ B8B7h
fsizehandle equ B8BAh
ftell equ B8BDh
ftesteof equ B8C0h
heapaddress equ B87Eh
heapalloc equ B881h
heapfree equ B884h
heaplock equ B887h
heapmaxfree equ B88Ah
heaprealloc equ B88Dh
kmcharreturn equ B803h
kmgetyellow equ B8D2h
kmreadkbd equ B806h
kmreadchar equ B9B3h
kmsetexpand equ B809h
kmsettickcount equ B80Ch
kmsetyellow equ B8D5h
kmwaitkbd equ B80Fh
lapcat_receive equ B8D8h
lapcat_send equ B8DBh
mcprintchar equ B851h
mcreadyprinter equ B854h
mcsetprinter equ B857h
padgetticker equ B872h
padgettime equ B875h
padgetversion equ B8DEh
padinitprinter equ BA4Fh
padinitserial equ B85Ah
padinserial equ B85Dh
padoutparallel equ B860h
padoutserial equ B863h
padreadyparallel equ B866h
padreadyserial equ B869h
padresetserial equ B86Ch
padserialwaiting equ B86Fh
padsetalarm equ B878h
padsettime equ B87Bh
pagemodeon equ BA49h
pagemodeoff equ BA4Ch
readbuf equ B812h
selectfile equ B8C3h
setdta equ B8C6h
testescape equ B815h
textout equ B81Eh
textoutcount equ B821h
txtboldoff equ B83Fh
txtboldon equ B842h
txtclearwindow equ B824h
txtcuroff equ B827h
txtcuron equ B82Ah
txtgetcursor equ B82Dh
txtgetwindow equ B830h
txtinverseoff equ B845h
txtinverseon equ B848h
txtoutput equ B833h
txtsetcursor equ B836h
txtsetwindow equ B839h
txtunderlineoff equ B84Bh
txtunderlineon equ B84Eh
txtwrchar equ B83Ch
Notepad memory map
==================
16K code/data sections always mapped to C000h
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³ video RAM ³ ³Protext ³Dictionary³Con-³Calc³Addr³Diary³ BBC ³
³---------------³ ³ ³ data ³trol³ ³book³ ³BASIC ³
³ RAM ³ ³ 1 & 2 ³ 6 blocks ³ ³ ³ ³ ³ ³
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³stack/variables³ \
³---------------³ B000 | common RAM (accessible by all programs)
³ RAM ³ /
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´ 8000 ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ ³ ³ ³
³ RAM ³ ³ PLS ³
³ ³ ³ ³
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³ ³ ³OS- remaps high³ ³ checking ³
³ RAM ³ ³---------------³ ³ code ³
³ ³ ³ Startup code ³ ³ ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ 0 ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
general notes:
most routines return carry set if successful
unless otherwise stated assume AF corrupted, other regs preserved
"all registers preserved" includes flags, but NOT alternate registers
the ALTERNATE register contents can NEVER be assumed to be preserved
(they are used as scratch registers in time critical routines)
==============
editbuf = B800
==============
line editor with options
zero-terminated string may be passed in buffer (HL)
this will display the initial contents
ENTRY - HL : pointer to input buffer
B : size of buffer (excluding terminating zero)
A : flags. b2=1 -> �� terminate entry
b3=1 -> input not echoed
b6=1 -> dotty background (character 176)
b5=1 -> edit unless characters entered
b4=1 -> delete trailing spaces
Other bits must be set to zero.
EXIT - c=0 z=1 ESC pressed
c=1 z=1 empty string input
c=1 z=0 at least one character entered
HL preserved
BC = last key token (or -1 if ESC used to terminate)
===================
kmcharreturn = B803
===================
returns a token to the keyboard buffer
ENTRY - BC = the token
EXIT - all registers preserved
================
kmreadkbd = B806
================
Gets a key token if there is one, does not wait
(Checks put back character and expands macros)
Returns tick event tokens if enabled
ENTRY - none
EXIT c=1 : BC = token (B=0 for simple character)
c=0 : no key token available
=================
kmreadchar = B9B3
=================
This routine is the same as kmreadkbd but macros are
exapnded and one or two other "behind the scenes" tasks
are performed. By using this routine you can be sure that
the Ctrl+Shift+S screen dump mechanism works in your code
==================
kmsetexpand = B809
==================
Defines a macro string
ENTRY - BC = macro token (between 256 and 383)
- HL points to new macro string (first byte is the length,
followed by the string - need not be zero terminated)
EXIT - c=1 if macro defined successfully
c=0 if insufficient room in buffer
(The buffer size is user configurable)
=====================
kmsettickcount = B80C
=====================
Enables the ticker event
There are 100 ticks per second
When a ticker event occurs t.tickevent is returned by kmreadkbd
ENTRY - HL : number of ticks before first event
DE : number of ticks between events
EXIT - all registers preserved
================
kmwaitkbd = B80F
================
Waits for a key token, uses kmreadkbd
(Checks put back character and expands macros)
Returns tick event tokens if enabled
ENTRY - none
EXIT c=1 : BC = token (B=0 for simple character)
==============
readbuf = B812
==============
line editor. See also editbuf.
ENTRY - HL : pointer to input buffer (empty)
B : size of buffer (excluding terminating zero)
EXIT - c=0 z=1 ESC pressed
c=1 z=1 empty string input
c=1 z=0 at least one character entered
HL preserved
BC = last key token (or -1 if ESC used to terminate)
=================
testescape = B815
=================
tests whether an ESC key has been pressed (STOP or FUNCTION)
waits for a key if one is found in the keyboard buffer
ENTRY - none
EXIT - c=1 if no ESC key in buffer
c=1 if ESC key in buffer but STOP not pressed
c=0 if ESC key in buffer and STOP then pressed
A is preserved
===========
col1 = B818
===========
if cursor is at start of a line do nothing
otherwise move cursor to start of next line (within window)
ENTRY - none
EXIT - none
===============
col1text = B81B
===============
same as textout, but calls col1 first
==============
textout = B81E
==============
displays string
ENTRY - HL : pointer to zero-terminated string
***************************************************************
WARNING - HL must not point into an upper ROM!
***************************************************************
EXIT - none
===================
textoutcount = B821
===================
as textout, returns character count in B
=====================
txtclearwindow = B824
=====================
clears current window and moves cursor to top left
================
txtcuroff = B827
================
removes the cursor from the screen
ENTRY - none
EXIT - all registers preserved
===============
txtcuron = B82A
===============
displays the cursor on the screen
ENTRY - none
EXIT - all registers preserved
===================
txtgetcursor = B82D
===================
returns the cursor position
ENTRY - none
EXIT - H = column (between 0 and 79)
L = row (between 0 and 7)
===================
txtgetwindow = B830
===================
returns the window coordinates
ENTRY - none
EXIT - H = left column (between 0 and 79)
L = top row (between 0 and 7)
D = right column (between 0 and 79)
E = bottom row (between 0 and 7)
c=0 if window is whole screen
c=1 if a smaller window has been
================
txtoutput = B833
================
displays a character or acts on control code
ENTRY - A = character
A=7 : beeps A=10 : LF A=13 : CR
All other values displayed as character (PC char. set)
EXIT - all registers preserved
===================
txtsetcursor = B836
===================
moves the cursor
ENTRY - H = column (between 0 and 79)
L = row (between 0 and 7)
EXIT - none
===================
txtsetwindow = B839
===================
defines a new window
ENTRY - H = left column (between 0 and 79)
L = top row (between 0 and 7)
D = right column (between 0 and 79)
E = bottom row (between 0 and 7)
EXIT - none
================
txtwrchar = B83C
================
displays a character
ENTRY - A = character. All values displayed (PC char. set)
EXIT - all registers preserved
======================
txtboldoff = B83F
txtboldon = B842
txtinverseoff = B845
txtinverseon = B848
txtunderlineoff = B84B
txtunderlineon = B84E
======================
These six routines enable or disable various display
attributes. They have no entry conditions and preserve all registers.
==================
mcprintchar = B851
==================
sends a character to the printer
ENTRY - A=character
EXIT - c=1 if successful
c=0 if not sent
A preserved
=====================
mcreadyprinter = B854
=====================
tests whether the printer is ready
ENTRY - none
EXIT - c=0 if busy
c=1 if ready
A preserved
===================
mcsetprinter = B857
===================
sets the printer type to be used by mcprintchar and mcreadyprinter
ENTRY - A=printer type, 0=parallel, 1=serial
EXIT - none
====================
padinitserial = B85A
====================
initialises the serial port using the global configured settings
turns on the UART and 4711
do not call this until needed - to prolong battery life
ENTRY - none
EXIT - none
==================
padinserial = B85D
==================
reads a character from the serial port
ENTRY - none
EXIT - c=1 if successful, A=character
c=0 if no character read
=====================
padoutparallel = B806
=====================
sends a character to the parallel port
ENTRY - A=character
EXIT - c=1 if successful
c=0 if not sent
A preserved
===================
padoutserial = B863
===================
sends a character to the serial port
ENTRY - A=character
EXIT - c=1 if successful
c=0 if not sent
A preserved
=======================
padreadyparallel = B866
=======================
tests whether the parallel port is ready
ENTRY - none
EXIT - c=0 if busy
c=1 if ready
A preserved
=====================
padreadyserial = B869
=====================
tests whether the serial port is ready
ENTRY - none
EXIT - c=0 if busy
c=1 if ready
A preserved
=====================
padresetserial = B86C
=====================
turns off the UART and 4711
call this when finished using the serial port to prolong battery life
ENTRY - none
EXIT - none
=======================
padserialwaiting = B86F
=======================
tests whether there is a character waiting to be read
from the serial port
ENTRY - none
EXIT - c=1 if character waiting
c=0 if no character waiting
===================
padgetticker = B872
===================
returns the address of a 4 byte 100Hz ticker
ENTRY - none
EXIT - HL is the address of the least significant byte
=================
padgettime = B875
=================
reads the time and date from the RTC
ENTRY - HL points to an 7 byte buffer to use
EXIT - HL preserved
data returned as above (see padsettime)
==================
padsetalarm = B878
==================
sets the ALARM date and time (within next month)
ENTRY - HL points to 3 byte data area
byte 0=date 1=hour 2=minute
EXIT - none
=================
padsettime = B87B
=================
sets the RTC date and time
ENTRY - HL points to 7 byte data area
bytes 0,1 = year (low,high)
2=month 3=date
4=hour 5=minute 6=second
EXIT - none
==================
heapaddress = B87E
==================
obtains the address of a memory block for a given memory handle
ENTRY - DE = memory handle
EXIT - HL = pointer to memory block
================
heapalloc = B881
================
allocates a block of memory from the heap
ENTRY - DE = number of bytes to allocate
EXIT - HL = memory handle in range [1,63] if successful
HL = 0 if failed
Note: heapaddress must be used to get a pointer to the memory block
Unless the block is locked with heaplock, heapaddress must be
called each time the memory block is used. IT MAY HAVE MOVED!
===============
heapfree = B884
===============
frees a block of memory
ENTRY - DE = memory handle, returned by heapalloc or heaprealloc
EXIT - none (preserves HL,BC)
Note: the memory handle passed must be a valid handle returned by
heapalloc or heaprealloc. This is not validated.
===============
heaplock = B887
===============
locks or unlocks a memory block
ENTRY - DE = memory handle
BC = non zero - the block is locked. It will not be moved
until unlocked so fixed addresses can be used as
pointers into the block
BC = 0 - the block is unlocked
==================
heapmaxfree = B88A
==================
returns the largest block size that can be allocated
ENTRY - none
EXIT - HL = largest free block size in bytes
==================
heaprealloc = B88D
==================
changes the size of an allocated memory block
ENTRY - DE = memory handle
BC = new size for memory block
EXIT HL = zero if failed to reallocate
The old block will not be freed but could have moved
HL = non-zero if successful
Note: if the block is being expanded, it must be assumed that the
base of the memory block will be moved (even if the block cannot
actually be expanded) so heapaddress must be called afterwards.
If the block is being contracted, the base will not move.
=============
fclose = B890
=============
closes a file
ENTRY - DE = file handle
EXIT - c=1 if successful, c=0 if failed
=============
ferase = B893
=============
erases a file
ENTRY - HL = zero-terminated filename
EXIT - c=1 if OK, c=0 if error (file not found)
===============
finblock = B896
===============
reads a block from a file
ENTRY - DE = file handle
- HL = buffer
- BC = number of bytes to read (> 0)
EXIT - c=1 if end of file not reached
- c=0 if eof (or error?)
- BC = number of bytes read
- HL = address after last byte read
KNOWN BUG (1.00,1.01) - finblock does not set the file position
so repeated calls will always read from the start of the file
Workaround: call fseek after calling finblock to set the pointer
============
finchar B899
============
reads a byte from a file
ENTRY - DE = file handle
EXIT - c=1 if successful, A=character
c=0, A corrupt if end of file reached
other regs preserved
================
findfirst = B89C
================
finds first file. setdta must have been called first
ENTRY - none
EXIT - HL=0 if no files
- HL points to file info structure if file found
- 1st item in structure is the filename, zero-terminated
- (up to 12 characters long)
- offset 13 is attribute byte
- offset 14/15 is the file size in bytes
===============
findnext = B89F
===============
finds next file. findfirst must have been called first
ENTRY - none
EXIT - HL=0 if no more files
- HL as findfirst if file found
==============
fopenin = B8A2
==============
opens a file for input
ENTRY - HL points to zero-terminated filename
EXIT - c=1 if successful, DE=file handle
c=0 if failed (file not found)
DE corrupt if error
A corrupt, other regs preserved
===============
fopenout = B8A5
===============
opens a file for output
ENTRY - HL points to zero-terminated filename
EXIT - c=1 if successful, DE=file handle
c=0 if failed (out of memory/too many files/file exists)
DE corrupt if error
A corrupt, other regs preserved
==============
fopenup = B8A8
==============
opens a file for input and output.
the file must exist already
ENTRY - HL points to zero-terminated filename
EXIT - c=1 if successful, DE=file handle
c=0 if file not found
DE corrupt if error
A corrupt, other regs preserved
================
foutblock = B8AB
================
writes a block to a file
ENTRY - DE = file handle
- HL = buffer
- BC = number of bytes to write (> 0)
EXIT - c=1 if OK
- c=0 if error
- BC = number of bytes written
- HL = address after last byte written
===============
foutchar = B8AE
===============
writes a byte to a file
ENTRY - DE = file handle
- A = character
EXIT - c=1 if successful
c=0, A corrupt if end of file reached
A corrupt, other regs preserved
==============
frename = B8B1
==============
renames a file
ENTRY - HL = zero-terminated old filename
- DE = zero-terminated new filename
EXIT - c=1 if OK, c=0 if error (file not found)
============
fseek = B8B4
============
moves the file pointer to a position within a file
ENTRY - DE = file handle
- BC = offset from start of file
EXIT - c=1 if successful
c=0 if offset past end of file (pointer not changed)
KNOWN BUG (1.00,1.01) - leaves error messages enabled (fnoisy)
Workaround: call fquiet after fopenout if necessary
============
fsize = B8B7
============
finds size of file
ENTRY - HL = zero-terminated filename
EXIT - c=1 HL=size in bytes, if found
- c=0 if not found
==================
fsizehandle = B8BA
==================
finds size of an open file
ENTRY - DE = file handle
EXIT - HL=size in bytes
============
ftell = B8BD
============
returns the value of the file pointer
ENTRY - DE = file handle
EXIT - HL = current file position
===============
ftesteof = B8C0
===============
tests whether end of file has been reached
ENTRY - DE=file handle
EXIT - c=1 if not eof, c=0 if eof
=================
selectfile = B8C3
=================
displays the file selector (clears the screen first)
shows all files and allows a selection to be made
using the cursor keys and RETURN
ENTRY - none
EXIT - c=1 if a file selected (RETURN pressed)
HL = filename
- c=0 if STOP pressed
=============
setdta = B8C6
=============
set memory block to be used by findfirst/findnext
ENTRY - DE= address of buffer (at least 35 bytes long)
buffer must be in common RAM (8000h-BFFFh)
EXIT - none
=================
fdatestamp = B8C9
=================
sets file date/time to current date/time
ENTRY - HL = zero terminated filename
EXIT - c=1 if successful
- c=0 if not found
===============
fsetattr = B8CC
===============
sets the attribute byte for a file open for output
if the file is open for input only there is no effect
ENTRY - DE = file handle
- C = attribute byte
bit 0 = system file
bit 1 = hidden file
bit 2 = BASIC program
bit 3 = binary file
EXIT - c=1 if successful
- c=0 if not found
===============
fgetattr = B8CF
===============
returns attribute byte of file
ENTRY - HL = zero-terminated filename
EXIT - c=1 A=attribute, if found
- c=0 if not found
preserves HL
==================
kmgetyellow = B8D2
==================
ascertains whether a 'yellow event' is pending
(so called because the FUNCTION key is coloured yellow)
a yellow event occurs (i) when the user has pressed one of the
the FUNCTION+key combinations that cause an immediate context switch
(FN+red, FN+green, FN+blue, FN+menu)
or (ii) when the machine is powered up and (because the option to
preserve context has not been set) needs to return to the main menu
ENTRY - none
EXIT - c=1, BC=token if yellow event pending
An application should exit normally as quickly as possible
Any UNSAVED FILES should be SAVED AUTOMATICALLY!
- c=0, BC=0 if no yellow event pending
Note: each of the yellow event keys return the ESC token (2FCh)
An application should call kmgetyellow whenever an ESC is read,
this distinguishes between a yellow event and an ordinary ESC.
==================
kmsetyellow = B8D5
==================
sets up a yellow event. Specialised use only.
ENTRY - BC = a yellow event token
EXIT - none
=====================
lapcat_receive = B8D8
=====================
reads a character from the parallel port using Lapcat protocol
ENTRY - none
EXIT - c=1 if successful, A=character
c=0 if no character read
==================
lapcat_send = B8DB
==================
sends a character to the parallel port using Lapcat protocol
ENTRY - A=character
EXIT - c=1 if successful
c=0 if error
====================
padgetversion = B8DE
====================
gets the firmware version number
ENTRY - none
EXIT - HL = version number (*100)
Thus, 1.03 returns 103
==================
diskservice = BA5E
==================
calls a Ranger disk routine
ENTRY - C = number of routine to call
A, HL, DE passed to the disk routine
EXIT - c=1 if successful, HL may contain returned value
c=0 if failed, A = error code (Ranger documentation)
C = 0 r_test
3 r_begin
6 r_change_disk
9 r_check_disk
C r_get_cd
F r_set_cd
12 r_set_dta
15 r_find_first
18 r_find_next
1B r_save_file
1E r_retrieve_file
21 r_set_attrib
24 r_create_directory
27 r_remove_directory
2A r_delete_file
2D r_rename_file
30 r_finish
33 r_disk_space
36 r_install
39 r_park_heads
3C r_format_track
3F r_format_done
42 r_save_wordstar
45 r_save_ascii
48 r_begin_program
4B r_load_program
System variables
<<<<<<<<>>>>>>>>
The following are the RAM based variables used by the operating system. It
is hoped that they will always use these locations in subsequent versions
of the software - but this is not guaranteed.
B000 copyofmmu0 ds 1 ; copy of MMU0 since it's a write-only port
B001 copyofmmu1 ds 1 ; copy of MMU1 since it's a write-only port
B002 copyofmmu2 ds 1 ; copy of MMU2 since it's a write-only port
B003 copyofmmu3 ds 1 ; copy of MMU3 since it's a write-only port
B004 gotcontext ds 1
B005 __savepearlmmu ds 1 ; extra vars needed in case we mustn't save context
B006 __saveaf ds 2
B008 __savehl ds 2
B00A saveaf ds 2 ; to save context, we need to save all the registers ...
B00C savebc ds 2
B00E savede ds 2
B010 savehl ds 2
B012 saveix ds 2
B014 saveiy ds 2
B016 savepc ds 2
B018 savesp ds 2
B01A saveafdash ds 2
B01C savebcdash ds 2
B01E savededash ds 2
B020 savehldash ds 2
B022 savemmu0 ds 1 ; ... and the memory state
B023 savemmu1 ds 1
B024 savemmu2 ds 1
B025 savemmu3 ds 1
B026 savecritpc ds 2
B028 savecritsp ds 2
B02A savingcontext ds 1
B02B nmimagic ds 4
B02F nmichksums ds 8 ; checksum bytes of first 8 roms
B037 criticalpc ds 2 ; save pc,sp for recovery from NMI during IRQ
B039 criticalsp ds 2
B03B ds 80 ; A small stack which we only use in initialisation.
; It can't sensibly overlap with anything in case we get an NMI
; requring immediate shut down after saving context.
; Subsequent power on will have to restore the context
B08B initstack
B08B diagnostics? ds 1 ; flag used in start-up, nonzero to do diagnostics
B08C saveprinstat ds 1
B08D kbdstate1 ds 10 ; 1 bit per key, 1=down 0=up corresponds to matrix
B097 kbdstate2 ds 10
PADKEYBUFLEN equ 32 ; this MUST be 2^n for positive integer n
B0A1 padkeybuf ds PADKEYBUFLEN*2
B0E1 padnextin ds 1 ; offset into padkeybuf
B0E2 padnextout ds 1
B0E3 padbufempty ds 1 ; nonzero if empty
B0E4 lastkbdstate ds 2
B0E6 thiskbdstate ds 2
B0E8 caps.state ds 1 ; 0=off FF=on
B0E9 savecaps ds 1
B0EA justswitchedon? ds 1
; variables above here are preserved after timeout
PADSERBUFLEN equ 32 ; this MUST be 2^n for positive integer n
B0EB padserbuf ds PADSERBUFLEN
B10B padsernextin ds 1
B10C padsernextout ds 1
B10D padserbufempty ds 1
B10E padserin_xoff ds 1 ; non-zero when XOFF has stopped inward transmission
B10F padserout_xoff ds 1 ; non-zero when XOFF has stopped outward transmission
B110 disablexonxoff ds 1 ; nonzero to disable software handshake
B111 ackirq ds 1 ; set non-zero when ACK interrupt occurs
B112 rptdelay ds 1 ; centisecs
B113 rptrate ds 1 ; centisecs
B114 rpttimer ds 1 ; count down timer for key repeat
B115 keytorepeat ds 1 ; key number
B116 rptkeystates ds 1 ; shift states
B117 rtcbuf ds 13
B124 d.alarmday ds 6 ; alarm day,hour,min ready for rtc chip
B12A alarmhappened ds 1 ; non zero when alarm has gone off, message pending
B12B alarmhappenedgotmsg ds 1 ; non zero when alarm has gone off, got message & pending
B12C soundcounter ds 1 ; non-zero if we're playing a tune
B12D soundptr ds 2 ; pointer to array of frequency,duration
B12F soundrepcount ds 1
B130 soundrepptr ds 2
B132 poweroffminutes ds 1 ; configured time to power off
B133 minutesleft ds 1
B134 minutecounter ds 2
B136 eventhappened ds 1
B137 preservecontext ds 1 ; 0=return to main screen at power on
B138 dontpreservecontext ds 1 ; 1=dont preserve (diag/batt)
B139 mainprog ds 1 ; 6=inbasic, 128=inexternal (foreground program id)
B13A currentprinter ds 1 ; 0 for parallel, 1 for serial
B13B currentmenu ds 2 ; pointer to current menu
B13D wasmenusel ds 1 ; after kmwaitchar this is 1 if menu used, 0 if not
; need this in fsel to know whether redraw needed
B13E lastsecond ds 1 ; checked to see whether to update the time
B13F clockon? ds 1 ; uses in Protext, non-zero when clock is enabled
B140 sdumpname ds 4 ; s.a, s.b, s.c etc. for screen dump name
; force d.workspace to an 8 byte boundary
B148 d.workspace ds 8 ; for massaged copy of symbol data (eg inverse/underline)
B150 d.datebuf ds 9+MAXMONTHLEN ; 27 January 1992
B162 d.asciitime ds 12 ; hh:mm:ss xm\0
B16E currentcfg ds cfg.len
B1BA g.outstream ds 1 ; bit 0 for screen, 1 for printer, 2 for file
B1BB g.h.outfile ds 2 ; file handle for charout if bit 2 set
B1BD g.pos ds 1 ; current column number (charout)
B1CE def.fname ds MAXPNLEN+1 ; Name of current file being edited
; first byte not zero if document open
; (yellow/red goes to edit mode, transfer from addrbook works)
B1DD def.first ds 1
; DO NOT CHANGE THE LAYOUT OF THE FIRST 21 BYTES
0024 len.findinfo equ 36
000D o.findinfo.attr equ 13
000E o.findinfo.size equ 14
0010 o.findinfo.time equ 16
0012 o.findinfo.date equ 18
0023 o.findinfo.mhandle equ 35
B1DE d.findinfobuf ds len.findinfo
0002 o.file.size equ 2
0005 o.file.mhandle equ 5
000D o.file.attr equ 13
000D o.direntry.attr equ 13
000E o.direntry.size equ 14
0010 o.direntry.time equ 16
0012 o.direntry.date equ 18
; char name[13]; /* 12 chars plus \0 (the file we found) */
; char attribute;
; uint size; /* filesize can't be bigger than 64k */
; uint time,date; /* if we allow time & date stamping */
; char flags; /* memory block flags */
; char handle; /* memory block handle */
;******************************************************************************
; PEARL.TXT DATA
;; The following 8 bytes are saved for each stream
B202 d.thisstream ds 8-8
B202 d.colrow ds 2-2 ; keep next 2 together
B202 d.row ds 1 ; 0-based within window
B203 d.col ds 1 ;
B204 d.winlefttop ds 2-2 ; keep next 2 together
B204 d.wintop ds 1
B205 d.winleft ds 1
B206 d.winsize ds 2-2 ; keep next 2 together
B206 d.winheight ds 1 ; height -1
B207 d.winwidth ds 1 ; width -1
B208 d.winset? ds 1 ; NZ if window
B209 d.state ds 1 ; bit 7 if inverse on
;; The following are recalculated from the above (in txtstrselect)
B20A d.colrowcount ds 2-2 ; keep next 2 together
B20A d.rowcount ds 1
B20B d.colcount ds 1 ; how many more cols to print on this line
B20C d.stream ds 1 ; current stream number
B20D d.fastpos ds 2 ; needed for quick screen update
B20F d.streamwsp ds 8*NSTREAMS ; 8 streams of 8 bytes each
B24F d.dateptr ds 2 ; non null for expanding time/date
B251 d.kmcharret ds 2 ; Returned character
B253 d.kstate ds 2 ; Key locks state
B255 d.caslocks ds 1 ; Shift states set by sticky key press
B256 d.sticky ds 1 ; non-zero in sticky key mode
B257 d.yellow ds 1 ; low byte of yellow/other key token
; stored by p.xlattoken which then returns ESC
B258 d.calcmode ds 1 ; nonzero if keyboard in calculator mode
B259 d.kmexplen ds 1 ; expansion string length
B25A d.kmexpptr ds 2 ; expansion string pointer
B25C d.expbuffer ds 2 ; address of expansion key buffer
B25E d.expbufptr ds 2 ; pointer to free byte
B260 d.expbufend ds 2 ; last byte in buffer
B2A1 macro_buf ds 256
; file selector variables
B3A7 fs_clicat ds 1 ; non-zero if CAT command, not fsel
B3A8 fs_showsizes ds 1 ; non-zero if showing file sizes (pad default=off)
B3A9 fs_showsys ds 1 ; non-zero if showing system files
B3AA fs_curfile ds 1 ; current file number offset from top left
B3AB fs_topleftfile ds 1 ; file number displayed top left
B3AC fs_numcols ds 1
B3AD fs_colwidth ds 1
B3AE fs_numshown ds 1
B3AF fs_maxfiles ds 1 ; max files that can be shown
FS_NUMROWS .equ 7 ; display rows
FS_NUMCOLS .equ 5
FS_COLWIDTH .equ 16
B3B0 fs_handle ds 2
FS_NUMSHOWN .equ FS_NUMCOLS*FS_NUMROWS
; number of files shown
B3B2 fs_numfilerows ds 1 ; rows of files in CAT command
B3B3 fs_startlist ds 2 ; start of file list
; zero if doing unsorted list
B3B5 fs_startdir ds 2 ; start of directory entries
B3B7 fs_endlist ds 2
B3B9 fs_numfiles ds 1 ; number of files in directory
B3BA fs_lastshown ds 1 ; last filenumber currently shown
; fs_topleft + FS_NUMSHOWN
B3BB tickcount ds 4 ; 32 bit counter needed for basic
B3BF ticksleftuntilevent ds 2
B3C1 tickreloadvalue ds 2
B3C3 tickeventpending ds 1
B3C4 countdowntimer ds 2
B3C6 savestream ds 1
B3C7 password ds 5 ; encrypted
B3CC pwbuf ds 5 ; clear
B3D1 realpwbuf ds 5 ; the real password saved for encrypting
B3D6 haspassword ds 1 ; non-zero if has password
;passwdmsg ds 2
B3D7 passwdlen ds 1
B3D8 passwordlocked ds 1 ; non-zero if locked (disallow soft reset)
B3D9 editingsecret ds 1 ; non-zero when editing secret file (can't delete it)
B3DA inmenu? ds 1 ; non-zero when inside menu - macros disabled
B3DB macro_count ds 1
B3DC recording? ds 1
B3DD macro_token ds 2
B3DF printfailed ds 1 ; flag set by mccheckprinter
; stops "finished printing" message
B3E0 wasmemoryerr ds 1
B3E1 inprotext ds 1 ; used in file selector, 0=was Fn-L, nonzero=Fn-2
**** End ****