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ZX Review #11-12
26 ноября 1997 |
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reader-reader - Driver input in serial mode and direct access from the files of TR-DOS.
The Reader - Reader
Music by ZET and MITCHELL
Boris Kuritsyn,
257010 Cherkassy, PO Box 1529
DRIVER INPUT
In sequencing mode
And direct access
FROM THE FILES OF TR-DOS
The author wrote this driver
(Or rather its first part) as
basic element of a high-level language compiler, development
which is engaged in the initiative
group from Cherkassy. But it is completely standalone program
that can directly used by those who wrote to
assembly, and a dilator designed BASIC - and those
who BASIC programmers.
In addition, analysis of her acquaint the reader with the
programming of the driver of the channels and streams, the
principles of writing BASIC extenders, the basics
parsing with the methods of extending the set of errors
BASIC.
What is the purpose of writing this
driver? There is a class of programs,
who must simultaneously work with many
files (and commissioning, and decommissioning)
themselves at the same time hold enough memory, so that about
simultaneous loading of all the required files can not be
speech. Opening the System Stream
for each file, they can work through this driver, even with
10 files in length, say, 60
KB at a time, at the rate of memory about 290 bytes per file. By
driver functions similar to the operators TR DOS file handling
direct / sequential access, but works with CODE-file and
similar files with non-standard types.
In addition, as shown by the "father
All programmers "Niklaus Wirth
(Author of Pascal, Modula2), then the program is simple,
correct and reliable when PROGRAMME STRUCTURE MEETS THE
STRUCTURE OF THE DATA.
To implement this principle, we need appropriate tools. One
of them is this driver because it allows the program to work
only with "abstract" aspects of data
ie in terms of "character", "read the position."
First, the technical aspects. The author prefers an
assembler ZX Turbo Assembler v.2.4, and listing is given in its
format. Hopefully, users of other
assemblers do not have problems
transfer program texts.
The author when writing programs
uses two auxiliary
modules: access to TR DOS
and the interception module system
errors.
TR DOS module is very simple.
This is analogous to a system call
# 3D13, which mistakes TR DOS
converts exceptions (call RST 8) codes 100-112, which
eliminates the need each time to check the error code
system. In addition, the call itself
done through a vector (dosVector), which allows you to "hang"
the call TR DOS additional
function at run time
program by replacing the values dosVector to address its
additional handler. 140.
; ****************************************
* *
* System call TR-DOS v5.0x *
* *
3; * (c) B. Kuritsyn, June 1996 *
* *
* File: dosapi.a *
* File Format: ZX TASM *
* *
; ****************************************
The exception "error TR-DOS"
excDosError equ 99
; Mistakes TR-DOS
dNoFile equ 1
dFileExists equ 2
dNoSpace equ 3
dDirFull equ 4
dRecOF equ 5
dNoDisk equ 6
dStrmOpened equ 10
dNotDskFile equ 11
dVfyError equ 13
dos db # c3; it jp (dosVector)
dosVector
dw dosIntr
; Call DOS shell functions
dosIntr push af
ld a, c
ld (_fncNo), a
xor a
ld (23823), a
ld (23824), a
pop af
call # 3d13
push af
ld a, (_fncNo)
cp # a; if the function was performed 10 (file search),
the code
jr z, dosOk; return - this is not an error code
ld a, (23823)
or a
jr z, dosOk; if there was a mistake to initiate an
exception ; Initiation exception DOS
dosError
add a, excDosError
ld (_errNo), a
rst 8
_errNo db 0
_fncNo db 0
dosOk pop af
ret
2
Interested exception handling may apply to the article [1].
Here I will say briefly: an exception - it is extremely
convenient programming technology, which allows implicit
conversions of handling errors or exceptional situations
without the need regular checks flags and return codes, etc. At
the same time ensures the conservation status of some elements
of the system and programs (at least the stack). In the form
below supports multi-level exception handling with the ability
to dynamically change set of conserved elements
and the exception handler.
Anyone interested can simply
analyze the text of the program. Briefly same can be said like
this: if at the beginning of a program, call try (see listing)
with the address of your error-handling routine, then
in the case of a call RST 8 anywhere
within the program management be passed to your handler. The
handler must, first of all, cause endTry to restore the stack
and remove for themselves. That the same call should be made
before command RET program.
140.
; ****************************************
; * Exceptions handle *
* Exception handling *
3; * (c) 1994-96 B. Kuritsyn *
3 * Version: 2.0 06/18/1996 *
* File: except.a *
; ****************************************
err_SP equ 23613
; ---------- External Treatment --------- try db # C3; a JP
(tryAd) tryAd dw mark
endTry db # C3
eTryAd dw unmark
; Continue the current exception
, (Just call the exception handler team JP)
; New exception code in the A
putErr ld (iy), a
; The same exception
contErr ld sp, (err_SP)
ret
; Change marking stack
; Entry: @ HL-new handler Try, @ DE-new handler EndTry
, Output: @ HL-old handler, Try, @ DE-old handler EndTry
chMarking ld bc, (tryAd)
ld (tryAd), hl
ld h, b
ld l, c
ld bc, (eTryAd)
ld (eTryAd), de
ld d, b
ld e, c
ret
; ------------ SALES -----------; Mark stack entry: @
DE-exception handler ; Destroyed: HL, IX
mark POP IX
LD HL, (err_SP)
PUSH HL
PUSH DE
LD (err_SP), SP
JP (IX)
; Demarcate the stack are destroyed: HL, IX
unmark POP IX
LD SP, (err_SP)
POP HL
POP HL
LD (err_SP), HL
JP (IX)
2
Necessary to stipulate that
those who do not know what a "channel" and "flow", before
continuing reading this article should read the chapter on
canals and streams in the famous three volumes Inforkoma
Programming native for the ZX Spectrum
or an application to the instruction
Users of text editor BK Write, is spread
author.
And now for the driver itself.
Which set of functions it should
perform? Firstly, it is opening the file: creating a channel
that is associated with the file, and connect any flow to the
channel. Secondly, the driver must allows you to read the file
bytes not only consistent but also
permuted index of reading directly to any position in the
file. Third, it is shutting down
File: the destruction of the channel, closing the stream. And
how, indeed, entering information, you ask? It's very simple -
the system procedure WaitKey (address # 15D4). Next, we
consider the annotated text driver (Note: the driver is
moments associated with the withdrawal of
file - this part of the driver is not
over, in addition, include
her story is not
possible due to the large volume).
Immediately turn to the basic idea of the driver: it is
necessary to give byte file, offset by a
file defines the current position. Position can be arbitrarily
changed at any time. When reading byte pointer
position moves to the next byte. Trying to read
anything beyond the end of the file generated an exception.
To implement this in a leader tape channel provides space
for one sector of the file. At any point in that buffer is
loaded sector corresponding to the current
position in the file. With any change in the position number of
the sector is monitored and, if necessary, the sector is
overloaded. 140.
; ****************************************
* *
; * DISK STREAMABLE I / O DRIVER v1.05 *
* *
* Driver streaming I / O *
* To / from files TR-DOS. *
* *
3; * (c) B. Kuritsyn, June 1996 *
* *
* File: stream.a *
* File Format: ZX Turbo Assembler *
; ****************************************
include "dosapi.a"
The length of the sector
sectLen equ 256
; System variables
chans equ 23631; pointer to channel
curChl equ 23633; pointer to the current channel
prog equ 23635; pointer to the program (for the end of
channels)
; System variables TR-DOS
dfDrive equ # 5d19; drive by default
searchCh equ 23814; number of characters for a name search
; Protsedury system, details of procedures see
[2]
makeRoom equ # 1655
reclaim2 equ # 19E8
strData equ # 171E +3
chOpen equ # 1601
callJp equ # 162C
; Channel input and output is named "F", so they can be
differences chat,
; Established leader tape of the signature:
readSign equ # 5678
writeSign equ # 6789
; Throwing exceptions
invStream
rst 8
db 23, "is used incorrectly Stream
invFileName
rst 8
db 14, "invalid name"
invDevice
rst 8
db 18, "invalid device"
endOfFile
rst 8
db 7, 'end of file "
; Shift in the leader tape, relatively unique structure of the
leader tape
see [3]
oPrint equ 0; address inference procedures
oInput equ 2; address of a procedure entry
oName equ 4; channel name
oSign equ 5; the signature of the channel
oClose equ 7; address of the procedure file is closed
oLength equ 9; length of leader tape
oIntern equ 11; More
; Image of the leader tape channel for reading
readRecord
DW invStream
DW inputIn
DB "F"
DW readSign, noOp
DW 1930 + sectLen; length of leader tape
DB 0; device (displacement oIntern +0)
DB "C"
DS 7; directory entry (...+ 1)
DW # FFFF; file position (...+ 17)
; Here: DS sectLen - buffer sector file (...+ 19)
rdRecLen equ $-readRecord + sectLen
; Procedure for entering characters from a file, the next byte
of the file
returns
, In A. Byte is always returned, so the state INKEY $ # 5 = ""
; Does not happen.
inputIn ld ix, (curChl); address of the leader tape
ld l, (ix + oIntern +17); current position in file
ld h, (ix + oIntern +18)
ld c, l
ld b, 0
add ix, bc
ld a, (ix + oIntern +19); fetching bytes from the
current sector
scf; Flag: Byte received from the device
push af
inc hl
call _seekRead; the transition to the next position
pop af
noOp ret
; Positioning in the current file for reading
; Input: HL-position
; --- External version, verify that the current channel - F and
it
open
; To read - if not the wrong thread)
seekRead
push hl
call testChl
ld l, (ix + oSign)
ld h, (ix + oSign +1)
ld bc, readSign
and a
sbc hl, bc
jp nz, invStream
pop hl
; --- Internal version
_seekRead
ld ix, (curChl)
, Check to see whether an end of file
ld c, l
ld b, h
ld e, (ix + oIntern +12); compared with the length of
the file
ld d, (ix + oIntern +13)
and a
sbc hl, de
; Position just after the last byte of the file, the buffer is
not overloaded zhaetsya
jr z, atEOF
jp nc, endOfFile
; Establish a new position
ld a, b
cp (ix + oIntern +18); in the same sector?
atEOF ld (ix + oIntern +17), c
ld (ix + oIntern +18), b
ret z; yes - complete
; Not - the new position of the corresponding byte from another
sector
file
; Download a new sector in the buffer
ld l, (ix + oIntern +15)
ld h, (ix + oIntern +16); position of beginning of the
file on disk
call makeLog; transformation into a logical sector
ld e, b
ld d, 0
add hl, de; a logical sector number that you want
download
call makePhis; inverse
ex de, hl
push ix
pop hl
ld bc, oIntern +19
add hl, bc
push hl
push de
ld a, (ix + oIntern)
ld c, a
call dos; drive select
pop de
pop hl
ld bc, # 105; boot sector
jp dos
; Convert Options "Sector L - track H" in the "logical
Sector HL "
; NOTE: The conversion to a "logical sector" can
easily
; Calculate the position of the sector on the disk as logical
Sector
And you can add and subtract like normal numbers.
; Transformation formula: log. sector = track * 16 + sector
makeLog xor a
140. srl h
rr a
srl h
rr a
srl h
rr a
srl h
rr a
or l
ld l, a
ret
; Convert Options "logical sector HL" in the sector L -
lane H "
makePhis
ld a, l
sla a
rl h
sla a
rl h
sla a
rl h
sla a
rl h
ld a, # F
and l
ld l, a
ret
; Type of file to open, changing this value before calling
openRead,
Or you can open a non-standard files
fileType db "C"
; Opening file for reading;
; Entry:
; A-number flow, @ DE/BC- name string (as usual: the address of
DE,
length of BC)
; Specified thread will be opened on the file.
openRead
exx
ld (stream), a; verifies that the stream is closed
call strData
ld a, b
or c
ld a, dStrmOpened; if not - the error DOS "thread
already
open "
jp nz, dosError
call newRdRecord; create a channel leader tape
ld (record), hl
push hl
exx
pop hl
call parseName; parse name
ld hl, (record)
inc hl
ld bc, (chans); find the offset of the leader tape
(Chans) ...
and a
sbc hl, bc
push hl
ld a, (stream)
call strData
pop bc
ld (hl), c; ... and open the requested stream to the
channel
inc hl
ld (hl), b
ld ix, (record)
ld a, (ix + oIntern)
ld c, a
call dos; drive select
ld c, # 18
call dos; setting a floppy disk
ld hl, (record)
ld bc, oIntern +1
add hl, bc
push hl
ld c, # 13
call dos
ld hl, searchCh
ld (hl), 9
ld c, # a
call dos; search for the file to open
bit 7, c
jr nz, noFile; if the file does not exist - everything
back to its original
state
ld a, c
ld c, 8
call dos; if the file is, get its directory entry
pop hl
ld c, # 14
call dos; and copy it to the leader tape channel
ld a, (stream)
call chOpen
ld hl, 0
jp _seekRead; establish a position on top of file
, In the absence of a file all returns to its initial state
noFile ld ix, (record)
call freeRecord; remove the leader tape channel
ld a, (stream)
call strData
ld (hl), 0; close of thread
inc hl
ld (hl), 0
ld a, dNoFile; an error DOS "no such file"
jp dosError
stream db 0
record dw 0
; Parsing the file name
, As "[drive:] name". If the drive is not specified, is taken
drive on
; Default. Name and drive into the realm of oIntern
leader tape.
; Input: HL-mail leader tape to open the channel, @ DE/BC- Line
Name
parseName
push hl
pop ix
ld a, b; empty name string - Error
or c
jp z, invFileName
ld a, (dfDrive); until the drive by default
ld (ix + oIntern), a
ld a, (fileType); set the file type
ld (ix + oIntern +9), a
ld hl, -3; name is longer than three characters?
and a
adc hl, bc
jp m, nameOnly; not - hence the drive to name just
Unknown
inc de; check with respect to the drive ...
ld a, (de)
dec de
cp ":"; if the second character - a colon ...
jr nz, nameOnly
ld a, (de); ... then the first - the drive
res 5, a; leads to the Uppercase
sub "A"; separate the correct names: A, B, C, D.
jp c, invDevice
cp 4
jp nc, invDevice
ld (ix + oIntern), a; drive is found and installed in
leader tape
inc de; shifted to the name ... (2 characters)
inc de
dec bc
dec bc
nameOnly
ld a, b
or a
jp nz, invFileName
ld a, c; if the name is 8 characters long - error
cp 9
jp nc, invFileName
ld b, c; if everything is ok - copy the name of leader
tape copyName
ld a, (de)
inc de
ld (ix + oIntern +1), a
inc ix
djnz copyName
ret
; Creating leader tape read channel
; Output: HL-mail created by the leader tape
newRdRecord
ld hl, (prog); at the end of Chans ...
dec hl
ld bc, rdRecLen; ... allocate memory for the leader tape
...
call makeRoom
inc hl
push hl
ex de, hl
ld hl, readRecord; ... and copy back the image of the
leader tape
ld bc, rdRecLen-sectLen
ldir
pop hl
ret
; Removing leader tape read / write channel
; Entry: IX-mail leader tape
freeRecord
ld c, (ix + oLength); of the leader tape get its length
...
ld b, (ix + oLength +1)
ld (recLen), bc
push ix
pop hl
jp reclaim2; ... and release the area occupied by them
recLen dw 0
, Check that the current channel - a channel of "F"
, Output: IX = (curChl)
testChl
ld ix, (curChl); if the name of the current channel ...
ld a, "F"
cp (ix + oName); ... not "F" ...
ld a, dNotDskFile
jp nz, dosError; ... mistake DOS "is not a disk file"
ret
, Close the file read / write stream A
close push af
call chOpen; makes the channel current
call testChl; verify that this flow is associated with our
channel
, Perform the procedure closing the channel
ld l, (ix + oClose)
ld h, (ix + oClose +1)
call callJp; transition to execution
; Free memory
ld ix, (curChl)
call freeRecord; remove the current channel of memory
, Close the stream
pop af
call strData
ld (hl), 0, 0 - stream closed
inc hl
ld (hl), 0
; Adjust variables for streams Streams 0-15.
; The fact that after the opening of this channel could be
opened
and
; Others. Their leader tape located in the memory after our
leader tape. ; With the removal of our leader tape displacement
of Streams in the
these
; Channels become null and void and must be corrected for
, The length of the remote leader tape.
ld d, b; offset the already remote leader tape
ld e, c
ld b, 16; scan the 16 streams
strmLoop
push bc
ld a, b
dec a
call strData; choose a value for the flow
push hl
pop ix
ld h, d
ld l, e
and a
sbc hl, bc; if it does not shift more of our ...
jr nc, noCorrt; ... no adjustment is required
ld h, b
ld l, c
ld bc, (recLen); otherwise reduce the bias on the length
of leader tape
and a
sbc hl, bc
ld (ix), l; and save
ld (ix +1), h
noCorrt
pop bc
djnz strmLoop; cycle for all streams
ret
2
Thus, the driver is written. And how
I use it? Elementary.
First, any free flow (say, # 5) open at
file:
140.
org 60000
jp start
include "stream.a"; enable drivers to ...
include "except.a"; ... and exception handling
name db "textfile"; to name the file ...
nameLen equ $-name; ... and its length
start ld de, name
ld bc, nameLen
ld a, 5
call openRead
2
File is opened. Now, for example, print it on the screen.
We will read a file character by character
and transmit bytes channel "S".
Because the process is completed except for "end of file",
catch the exception: 140.
ld de, endOfPrint; address of the handler
call try
2
Now you can display the file in
"Infinite" loop.
140.
waitKey equ # 15D4
process ld a, 5; file stream
call chOpen; chOpen = # 1601
call waitKey; introduce the symbol
push af
ld a, 2; flow screen
call chOpen
pop af
rst 16; derive symbol
jr process
2
At the end of the file or
another exception management
will be sent here:
140.
endOfPrint
call endTry; remove handler
ld a, 7
cp (iy); current fault - it's "end of file"?
jp nz, contErr; if not - keep it
spread the word
; Yes - everything is in order, the withdrawal is completed
ld a, 5
call close; close disk file
ret
2
What about BASIC? Like
would be able to open
files directly from the operators BASIC.
Nothing could be easier. The following interface to the BASIC
driver realizes this and more
something: it converts the new
DOSovskie exceptions to the new
BASIC errors, which are displayed in the same way as
conventional. Except He displays the status of the streams
system on the screen or in any
another thread. New operators
BASIC is as follows:
LET d = 64000
REM opening <flow> on <filename>
RANDOMIZE USR d: OPEN # stream, filename $
REM closing disk file associated with the <flow>
RANDOMIZE USR d: CLOSE # stream
REM transition to in the file associated with
<thread>
PRINT # thread;: RANDOMIZE USR d: GO TO position
REM display information about the state of flux at <thread>
REM to display flow = 2
RANDOMIZE USR d: LIST # stream
A small remark about the operator GO TO: operator PRINT, you
see ahead, only makes the flow of current as well as working
with GO TO current flow. Note the ";" at the end of the operator
PRINT.
Operator LIST lists
all open streams with an indication of the channels that they
are open.
Direct input from a file in the usual way: the operator
INPUT # thread; simv_peremennaya $
to enter a character string or
operator
LET simv_peremennaya $ = INKEY $ # input stream for a single
character
The second way is preferable, as in the ZX Spectrum has this
feature: assumed that the operator
INPUT data is entered only from
flows associated with the keyboard and the sound of the
keyboard is handled in a statement INPUT. Therefore, when you
enter the file you hear the squeaks of the sequence "keystroke"
in the enter each character. In addition, input lines will be
completed only upon receipt of a character code Keys <Enter> (#
0D) and this very character in the string will not be included.
Throughout the program, well
It can be seen as a dilator BASIC
not only performs the action, but
and analyzes the syntax of the program.
140 .;*****************************************
* *
; * BASIC INTERFACE TO *
; * DISK STREAMABLE I / O DRIVER, v1.05 *
* *
* The interface to the BASIC *
* Download streaming I / O *
* To / from files TR-DOS. *
* *
3; * (c) B. Kuritsyn, June 1996 *
* *
* File: basint.a *
* File Format: ZX Turbo Assembler *
;*****************************************
; Codes tokens
t_open equ # d3
t_close equ # d4
t_goto equ # ec
t_list equ # f0
; System variables (or bias)
oFlags equ 1
oTVFlag equ 2
oFlags2 equ 48
oFlagX equ 55
oXPtrHi equ 37
defAdd equ 23563
strms_6 equ 23574
; Used semiconductor ROM. For details, see [2].
class06 equ # 1C82; syntax. Analyzer - should be
numeric expression
class0A equ # 1C8C; syntax. Analyzer - should be a line
Character
separator equ # 1B6F; parser - should be
lexeme
stkToA equ # 1E94; stack calculator - the A
stkToBC equ # 1E99; stack calculator - in BC
stkFetch equ # 2BF1; stack calculator - in the A / BC / DE
clsLower equ # 0D6E
setMin equ # 16B0
copyBuff equ # 0ECD
stackA equ # 2D28; A - a stack calculator
printFP equ # 2DE3; print number from the stack calculator
po_mess equ # 0C0A; display a message from Table A (DE)
org 64000
; Entry point
startUp ld de, newErrors; new handler issklyucheny
call try
ld c, ":"; a separator after the USR 64000
; Separator verify that the current symbol interpretiruenmy
namely
, Is as follows. If not - error "nonsense in BASIC"
call separator
ld c, a
rst # 20; take the name of the operator ...
ld hl, statms; ... and look for it in the table
Statms
jr compare
nextSearch inc hl
inc hl
compare ld a, (hl)
inc hl
or a
jr nz, cont_comp; if the table was over - a mistake
rst 8
db # b; Nonsense in Basic
cont_comp cp c
jr nz, nextSearch
ld a, (hl); found, select the address of the handler
...
inc hl
ld h, (hl)
ld l, a
call callJp; ... and run it
call endTry; remove the exception handler
ret
; Table description operators.
; Format: token, the address of the handler, token, address,
handler,
... 0.
statms db t_open
dw _open
db t_close
dw _close
db t_goto
dw _goto
db t_list
dw _list
db 0
listStrm db 0
The text for the operator LIST
listMess db # 80, "Streams status:", 13 + # 80
db ": opened to", 34 + # 80
140.
db 34,13 + # 80
3; operator LIST # stream
_list ld c, "#"; check symbol stream
call separator
call class06; should be followed by a numeric
expression
call stkToA; it - in the battery
call chOpen; open channel for output
ld de, listMess
sub a
ld (listStrm), a
call po_mess; output header
listNext ld a, (listStrm); for the flow ...
call strData; ... selected data from the Streams
ld a, b
or c
jr z, listCont; when closed - the next thread
ld a, "#"; print symbol rate ...
push bc
rst 16
ld a, (listStrm)
call stackA
call printFP; ... and its facilities
pop bc
ld hl, (chans)
add hl, bc
inc hl
inc hl
inc hl; definition addresses oName bias in the
channel
push hl
ld a, 1
ld de, listMess
call po_mess; message "open with" ...
pop hl
ld a, (hl)
rst 16; ... such and such a channel
ld a, 2
ld de, listMess
call po_mess
listCont ld hl, listStrm
inc (hl); next thread
ld a, 16
cp (hl)
jr nz, listNext; move to the next thread
ret
3; Operator OPEN # stream, name $ - no comment
_open exx
push hl
call openParams
call openRead
pop hl
exx
ret
; Parse OPEN statement
openParams call class06; must be thread number - a stack
Calculator
ld c, ","
call separator; then a comma
call class0A; then the character expression - the
filename
rst # 28; exchange name and the flow in some places
on the stack
db 1, # 38; exchange
call stkToA; stream - in the battery
push af
call stkFetch; name - in the DE / BC
pop af
ret
3; operator CLOSE # stream
_close call class06; must be thread number - a stack
Calculator
call stkToA; stream - in the battery
jp close
; Operator GO TO pos
_goto call class06; number - position in the file
call stkToBC; with stack calculator in BC
ld h, b
ld l, c
jp seekRead
; Error handler: visualizes new errors
newErrors call endTry; remove handler
halt
ld a, (iy); error code
cp excDosError + dNoFile
jp m, contErr; usual errors SOLD further
; This part of the program virtually repeats the action
standard
; Error handler from the ROM to output error messages.
See
, [3] from the address # 1303
res 5, (iy + oFlags)
bit 1, (iy + oFlags2)
call nz, copyBuff
ld hl, 0
ld (iy + oFlagX), h
ld (iy + oXPtrHi), h
ld (defAdd), hl
ld hl, 1
ld (strms_6), hl
call setMin
res 5, (iy + oFlagX)
call clsLower
set 5, (iy + oTVFlag)
ld a, (iy)
sub excDosError + dNoFile
ld b, a
add a, "a"; new codes Posts
rst 16
ld a, ""; gap
rst 16
ld a, b
ld de, messages; new posts in this table
ld (iy), # FF
jp # 1346; further processing of the standard - in
ROM
; Table text messages about new bugs (in the format of the
procedure
PO_MESS)
messages db # 1980, "No fil", "e" + # 80
db "File exist", "s" + # 80
db "Disk ful", "l" + # 80
db "Dir ful", "l" + # 80
db "RecNo overflo", "w" + # 80
db "No dis", "k" + # 80
db "(7) DOS erro", "r" + # 80
db "(8) DOS erro", "r" + # 80
db "(9) DOS erro", "r" + # 80
db "Stream opene", "d" + # 80
db "Not disk fil", "e" + # 80
3 db "(1912) DOS erro", "r" + # 80
db "Verify erro", "r" + # 80
; Enable drivers and exception handling
include "stream.a"
include "except.a"
; *** End of basint.a ***
2
Well that's all. I think to check the interface you will be
able to write as many programs. I hope that my brief (Due to
the large amount of assembly code) comments given at least a
general idea of work program and the program will be useful to
you.
If you have any problems or
specific questions you can
write to the author at the address above.
REFERENCES
1. B. Kuritsyn. Interception system
programming errors in the
Assembler for PCs "ZX
Spectrum ".: Radio amateur, 10 '
1994; p. 12 - Minsk, 1994.
2. Logan, O'Hare. Full description Rom ZX Spectrum.:
"ProgrammAss" - Kharkov, 1992.
3. K. Kurylovich, D. Madej, K. Marasek. Guide to the ZX
Spectrum.: "Program-Ass" - Kharkov 1992.
*
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В этот день... 21 November