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Voyager #03
19 октября 1998 |
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PROFI CLUB - Studying CP / M (compatibility, processors, terminals).
(C) Chertkov VY
Music: BURATINO remixed by KENOTRON
STUDIES CP / M
Part 1
This article is written as supporters Profi
and CP / M, and a fierce opponent in any case -
not crooked, just read, and who knows, maybe
and find something interesting for yourself. If you
something already know this or just heard -
not a problem - again read not hurt (worse on the
that no one will be, although you never know ...). I also want
to noted that most of the above information gathered from
various sources (magazines, books, docks, Some sources, docks
with the PC, etc.) throughout my acquaintance with the pros.
All of this collected literally bit by bit, because no
information no ....
*
1. Introduction
The first general-purpose microprocessor from Intel 4004
appeared in 1971. He could run any program written in a system
of their teams, could enter data, process them and display the
results. The word length of the microprocessor was only 4 bits
(notebooks). The microprocessor contains about 1000
transistors, performed 8,000 operations per second and has been
focused on the use of calculators.
A year later, Intel introduced a microprocessor firm 8008
- 4004 analog with word length 8 bits and a faster. But the
truly epoch-making was Issue microprocessor 8080 - we can say
with it all began. This MP was introduced to the market in
early 1974 and immediately attracted attention because was
powerful enough to build a small computer. Later, Intel
introduced a set of chips from which you can create a variety
of microprocessor-based systems. Some of these LSIs are used
now.
A little later on sale there, as designers to build their
own hands, and turnkey computers based on IP i8080. No
operating system for them, of course, did not exist, to control
the computer using special program, named for the functions
they perform monitors. Monitor lets you view and edit the
contents of memory cells, memory is filled with constant, run
programs, etc. Also, monitors allows you to unload blocks of
memory to external media (tape, cassette tape) and upload them,
if necessary, back into RAM. The program monitors generally
sewn up in ROM and takes control immediately after powering on
the computer that was convenient for the user.
Monitors also includes a set of frequently
used procedures, such as input bytes from the keyboard, output
characters to the terminal or printer (TTY), and others. This
is explained by the fact that any more or less difficult
program uses these functions. Because they are similar to the
corresponding fragments other programs, not to repeat one and
the same procedure in each program, they were placed in
monitor. The advantage lies in the fact that now
to create a program spends less time and
save space in RAM. Procedures were located
specific addresses were available to any program. This, in
essence, was the embryo of the operating system.
Appears in the mid-70's on the market of personal computer
with external memory on magnetic disks affected the evolution
of operating systems. Having quick access to anywhere in the
disk and having an elusive for the tape data rate, the drive
allowed to apply a new orderly way to store data on external
carriers. There is a need to create an operating system,
effectively managing the data on external media (to manage
files on disk). When working on a PC user has to frequently
run a variety of programs, which, in addition
the same should exchange data among themselves. In addition, it
is necessary to solve more specific terms tasks: partitioning
disks, copy and delete files, print them on your printer or
plotter, the organization of local networks, and more. The
optimal solution was that all of the above "assumed the"
operating system - complex program (or rather, a set of
programs), which manages computer resources.
Because the main task of the OS - to manage
computer, it makes it the best way, but the software included
in the OS - the most perfect. If it were not so, then what is a
meaning in the OS?
In 1975, Harry has created an operating Kildel
system CP / M computers, built on the basis
I8080 IP and supports the drive.
System manufactured by Digital Research. Name of the system
means the Control Program for Microcomputers (control program
for microcomputers). The operating system is a program
who ran the machine resources, such as
external memory (file structures), keyboard,
terminal, printers, serial link, etc.
To operate the system required about 5K of RAM, all
the rest provide a program. Form of communication with the
system operator was a dialogue, ie operator introduced the team
- as a string in which the first word has its own team, and
everything else - parameters of this command. The results are
displayed on the terminal (previously teletype or printer), and
the system in turn, could have requested any options
operator. A year later, was released the second version
and a little later than V2.2, which became a de facto standard
on the OS for an 8-bit computer. We have circulated under the
different names variants of this particular system. Version 3.0
supports real-time, worked with the sectors of large size (1024
bytes) and has been focused on the processor 64180. System
require at least 128K of RAM. The fourth version multitasking -
the so-called system MP / M. Information about this system is
extremely small, and to find any description (not that
technical guidance, even just a user manual) is not possible.
For ease of installation on the computer of an arbitrary
configuration operating system was divided into two parts - the
actual disk operating system (BDOS - Basic Disk Operating
System) and input / output system (BIOS - Basic Input / Output
System). BDOS module represents the core of the operating
system, implementing a "logical" level I / O: Support for logic
devices, accounting and the distribution of disk space, console
I / O, support files. You could even say
that file support is a major task BDOS,
and it provides many opportunities for this.
Module BIOS, by contrast, contains only the simplest
functions of controlling external devices. In general, BIOS is
a set of programs for Service main components of the computer,
such : keyboard, screen, printer, disk drives
and other device drivers be executed
only the simplest functions. For example, BIOS can read some
sectors of the disk, but the organization of data files is
missing here. The system BIOS and device drivers form a
"physical" level operating system.
The first part (BDOS) could be transferred to
any computer with appropriate processor without modification.
It is required to only requirement is the presence of RAM in
the lower memory addresses, not occupied frame buffer, ie
"Pure" memory, which would have carried out the program and
placed the OS itself. Also, for Time was necessary to have at
least one disk device (this may be the drive or hard drive).
All I / O BDOS exercises by calling the system BIOS, so manner
attained a high mobility of both the CP / M, and the programs
running under its control. Program is much less dependent on
hardware. In BDOS'e contained Yeshe one component of the OS -
CCP (Console Command Processor) - Processor Console
commands, or simply a shell.
This is a small program that automatically starts after you
restart the system. It carries reception and execution of user
commands. In fact - This is a common application, but without
it the work of a completely impossible - it is the primary
hull. Dialogue with the operator is just CCP, BDOS same -
is simply a set of functions and nothing more.
The second part of the system (BIOS) - (small and
relatively simple) is specially programmed
for each machine with regard to its hardware features. This
part of the system created by the producers themselves PC. Thus
it turns out that the CP / M compatible with most 8-bit
computers.
It is a broad system compatibility, as well as several
other features, such as support for transit or external
command, made her so popular.
* TO BE CONTINUED *
ranzitnyh or external command, made her
so popular.
* TO BE CONTINUED *
(C) Chertkov VY
Music: 'CROON' / 13.10.98 (:-<>)/ KENOTRON
STUDIES CP / M
Part 2
2. Compatibility
The operating system CP / M is so widely spread through
ease of installation it on the computer of an arbitrary
configuration and a large number of software created for this
system.
Like any professional OS, CP / M has a remarkable
property: the components of the system can evolve
independently, while maintaining full compatibility with the
earlier written software! Because The system uses certain
conventions, the modules have certain entry points. Program
invokes the operating system in a specific way, for This is
achieved by high mobility and compatibility.
Here we must note one thing. All programs under the CP / M
can be divided into two types: those that work only through the
standard means of system (BDOS 'BIOS), and those except the OS
can apply directly to the hardware on your computer. Program of
the first type, usually operate at any company that is running
CP / M. If this program does not go ", it means that some
components of the system is implemented incorrectly. Typically,
the programs of this type of plain-looking, are not
window-menyushnogo interface (especially icons) - this kind of
fee for versatility and mobility. Although in 1981 the American
Institute Standards (ANSI) has developed iskeyp sequences that
control color output symbols and cursor shape. But the program
under the CP / M, oriented to ANSI, I have met very rarely.
Still, with graphics, they can not work ...
Programme of the second type, on the contrary, colorful and
pleasing to look at, because full advantage of the apparatus.
They can say, written mostly not for CP / M, and for this
particular computer. Once the program is drawn directly to
equipment (use the IN / OUT or drawn directly to video memory),
then, of course, it will only work on "native" computer. Move
it to another PC with a different architecture quite difficult
or even impossible. Ie, the program is tied to the hardware.
Such, for example, most programs on the profiles. On the other
CP / M-cars they do not go, because using the hardware
capabilities of a specific computer.
From all this it follows that if
writing a program is running CP / M
No one forces you to, for example, to display the text on the
screen, to work exclusively through BDOS. If you do not intend
to carry this program to other PCs, it is safe to write their
own procedures to the screen and keyboard. Another thing, if
the standard features you completely satisfied, then we can
work through them. Ie, y programmer has a choice (and
programming on the Spectrum - no): or use standard email
functions or write your own. Or, you can create a special
system that extends the display I / O - a kind of complement
the operating system, I mean the resident library windows
Windows on the Profi. Just as with the CP / M: more convenient
to write the function once and collect them in unit than each
time to recreate them in another program. Yes, and a resident
of this can be improved (or, for example, will be a device such
as graphics accelerator - will be enough just to change some
procedures to residents - and all of hockey!), This will work
better programs written under it! Program, though, is not
targeted at the library, improvements to the equipment will not
notice.
Under CP / M was created decent base programs. Where
all this software - another question. The thing is that the
popularity of this system took place at the end of the 70 - top
80's, but at that time, you know, PCs have not produced. From
the PC the most were distributed Robotron 1715, imported
from the GDR. The ordinary man it was virtually unavailable,
ie, mass distribution programs, as now, was not. And the
programs were only those who could work on these computers (No
older version of CP / M 2.2, processor, best, Z-80, but in
general - i8080). All that was - this is what was used in
colleges and some enterprises: spreadsheets
SuperCalc, MultiPlan, DBMS dBASE II, and a few
text editors like Word Star, Final Word
Refor + or some programming languages. And this
everything! Negative factor was the fact that the
late 80's the company began to buy IBMsovmestimuyu technique,
and from CP / M tried to get rid of. As a result, now from
proprietary software were Some fragments, fragments and scraps.
What's left, has remade many times (as it was written - "the
same program at a time reworking a few morons"), were even
entire institutions, takes a full translation of the Western
programs in Russian. So, game for ZXSpectrum, who came from
Poland, one can generally assume that brand! Pure CP / M'ovskie
program for professionals gathered with great difficulty:
something found in one place, something - in other - and, as
Typically, all in a terrible state. The only way
I think, is now available nepokalechennye
program under the CP / M - is a dedicated CP / M sites (sites)
in InterNET.
* TO BE CONTINUED *
.
(C) Chertkov VY
Music: THE BEST ITALIAN-'VENICE 'by KENOTRON
STUDIES CP / M
Part 3
3. Processors
As already mentioned in the introduction, the system
CP / M was written for the processor i8080. Immediately
raises the question: "Why, actually, not for Z80?
After all, he's better. "The thing is that the firm Zilog
released its processor two years later than
released i8080, a PC at its base, respectively,
appeared later. Of course, 2 years - a small
term, but in the computer industry is an eternity.
Subsequently, there were versions of the system-oriented and
Z80, which required less memory and run faster.
Who is late - he loses. Zilog and
subsequently created a much more advanced LSIs in
all respects than Intel'ovskie, but lost in the
time. Intel chips are produced, they are created
Computers have evolved standards in technology and
etc., and after that Zilog presented its development - but the
time lost and the market is already captured.
*
Now consider applied in the PC running the system CP / M
microprocessors:
i8080
We can say the first normal microprocessor. Executes 68
basic commands, has 6 modes addressing. Registers 8 / 16 bits.
Addresses 64K of memory. Data Bus Width 8-bit address bus - 16
bits. Completed in CMOS. Clock Speed 2.5
MHz. Housing with 40-pin DIP. Powered +5 V, +12 V
and-5V, clock signals in phase, and amplitude of 12V. Address
bus and data should always (!!!) buffered bus-shapers. Performs
an average of about 250 thousand operations per second. One
mode interrupt handling. No teams on the transition, one set of
registers. As a programmer's perspective, and from the point of
view Developer apparatus, the processor is very uncomfortable.
Although, if a program written for this processor
then it will work on any other processor
(From this list, of course).
i8085
Advanced i8080. Modify
way technology is now on the wiring diagram MP
closer to the 16-bit. Unipolar +5 V supply, all
conclusions TTL-compatible. 5 MHz clock frequency. Has a
built-in controller continuously. Compared with i8080 has only
two additional commands (for Management Interrupt Controller).
The rest - Fully compatible with the i8080. Performs on average
500 thousand operations per second (0.5 mips).
Z-80
Several engineers firm Intel, developing
i8080, disagreed with the leadership, came out of it
composition and organized his own company - Zilog.
In 1976 he released his version of the MP, in comparison with
the i8080, it has the additional registers and team. Any
program written for the i8080, will work on the Z80. Processor
consists of 8500 transistors perform 158 basic commands, has
10 addressing modes (there were prefixes CB, DD,
ED, FD). Registers 8 / 16 bits, the address 64K of memory.
Data Bus Width 8-bit address bus of 16 bits. Performed on n-MOS
technology. 4 MHz clock frequency. Housing with 40-pin DIP. One
power supply +5 V, all inputs and outputs are compatible with
TTL. At a frequency of 4 MHz, on average perform 400 thousand
operations per second (not NOP'ov!). Developed system interrupt
two types: masked (INT) and Non-maskable (NMI).
Mode 0 maskable interrupt ekvivlenten regime
in i8080. Has the ability to regenerate the dynamic RAM.
Subsequently released versions of the microprocessor at 2.5
(Z80L), 6 (Z80B) and 8 (Z80H) megahertz. Compatible
microprocessors produced many firms, there are even options for
10 and 14 MHz! (Ie up to 1.4 mips)
By Z-80 can be connected to any of the LSI package i8080.
64180, Z180
Further development of the Z80. Addresses 1MB of memory,
clock frequency 10 MHz. Data Bus Width 8-bit address bus - 20
bits. Housing with 64-pin DIP or PLCC 100-pin. Has built memory
manager. Memory is divided into pages of 4K, plug in two
windows - at address 0 and address 8000h. The width of
registers, as in the Z-80 - 8 / 16 bits. Significantly improved
interrupt system, a built-interrupt controller. Added new
teams. The wrong code, restart the operation worked through 0.
An average of 1 million operations second (ie, 1 mips).
Performs all documented commands Z-80.
New commands:
Team test checks - installed on your
Reg. A specified in the mask bits (mask - operand), unlike the
team BIT that is checked several bits. Teams IN0 and OUT0
designed to access built into the processor peripherals (ports
00 .. FF).
ED 00 NN IN0 B, (NN); NN-B
ED 01 NN OUT0 (NN), B
ED 04 TST B; check bits
; (TEST A, B)
ED 08 NN IN0 C, (NN)
ED 09 NN OUT (NN), C
ED 0C TST C
ED 64 NN TST NN
ED 74 NN TSTIO NN; mask is read from
; Port NN
......................
ED 38 NN IN0 A, (NN)
ED 39 NN OUT0 (NN), A
ED 3C TST A
ED 4C MLT BC; BC = B * C
ED 5C MLT DE
ED 6C MLT HL
ED 7C MLT SP
ED 1976 SLP; energy-saving
; Mode
ED 83 OTIM
ED 8B OTDM
ED 93 OTIMR
ED 9B OTDMR
Z-280
Address 16 MB of memory, ie, Address bus width 24 bits.
Clock speed (minimum) 25 MHz. Data bus width 16 bits (twice the
performance at the same clock speed). Built-in memory manager,
segments. Has a conveyor system for processing commands,
built-in cache memory (CACHE Tier 1) and the ability to connect
math coprocessor. On average, 4.5 million operations per
second. Performs all documented commands Z-80 and Z-180.
New teams (one found in the documentation for one emulator, ie,
not all):
CB 30 TSET B; testing bits and conditions
; SETTING
CB 31 TSET C
CB 32 TEST D
CB 33 TSET E
CB 34 TSET H
CB 35 TSET L
CB 36 TSET (HL)
CB 37 TSET A
These commands can be easily distinguished Z-280
from Z80, a typical example:
LD A, 40H
DB 0CBH, 37H
JP M, Z-80
JP P, Z-280
Thus, the program Z-80, using
"Undocumented" commands (SLI - generally useless swill) to work
on the Z-280 will be wrong! Moral: as no improvement, these
undocumented commands do not bring it and apply They should not
be - suffer the compatibility and more.
NEC V20, V30
The microprocessor is built on the architecture of i8086,
but has a subset of commands i8080. Bus Width
Data 8 / 16, at 1 MB of RAM. Built on the CMOS clock frequency
10 MHz. Performs average of 1.5 million operations per second.
Used in dvuhsistemnyh PC (eg, DEC Rainbow), because
can work in systems MS-DOS, CP/M-86 and
systems that are compatible with CP/M-80.
Running the program in the codes i8080 mode
i8086 is a team BRKEM N, where N - number of software
interrupts 8086, in this vector contains the code address i8080
for execution. Registers 8086 in the transition mode 8080 is
almost entirely meet the exception register sp 8080 it becomes
equal to bp 8086.
0F FF NN BRKEM NN; Go to the emulation code
; I8080
In the i8080 added to the team:
ED ED NN CALL N; call interrupts 8086
; (INT N)
ED FD RETEM; transition (recovery) mode
; I8086
* TO BE CONTINUED *
; (INT N)
ED FD RETEM; transition (recovery) mode
; I8086
* TO BE CONTINUED *
system (BIOS) - (small and
relatively simple) is specially programmed
for each machine with regard to its hardware features. This
part of the system created by the producers themselves PC. Thus
it turns out that the CP / M compatible with most 8-bit
computers.
It is a broad system compatibility, as well as several
other features, such as support for transit or external
command, made her so popular.
* TO BE CONTINUED *
ranzitnyh or external command, made her
so popular.
* TO BE CONTINUED *
(C) Chertkov VY
Music: SPECIAL COMPOS 'by KENOTRON'96
STUDIES CP / M
Part 4
4. Terminals
This may sound strange, but adapters for personal
computers did not appear immediately. First, to display
alphanumeric information were invented device based on the CRT,
called terminals. The name was chosen in such apparently due to
the fact that these devices are graduates of the chain of
transmission. The terminal is a monitor with built-in adapter
allows you to display 80 characters per line when the number of
rows from 24 to 30. The adapter contains its own
processor and video memory. To display the symbol
you just need to send the code for the character terminal.
The symbol appears in the current cursor position, after which
the cursor moves one position to the right. If the line is
off-screen, then it or broke off (WRAP OFF), or transferred to
Next physical line (WRAP ON). Switching
WRAP mode through software or hardware. To fill the entire
screen scrolling was implemented up (Scroll Up) to clean the
last row. In addition to ordinary characters to recognize the
terminal control codes - end of line (CR), linefeed (LF), clear
the screen (CLS), positioning the cursor (CURSOR MOVEMENT),
delete the character left of cursor (BACKSPACE), etc.
The adapter connects to the computer using
any interface - Serial (most often) or in parallel. Thus,
connect the terminal to the computer was not difficult -
important to have available the appropriate interface. From the
standpoint of programmer's terminal looks like printer, the
difference lies in the speed (terminal is much faster) and
system commands. The terminal, like a printer accepts a stream
of characters from which stand out commands and data.
Terminals produced a set of firms here, for
example, a few names: Monroe, Morrow, DEC,
Xerox, Epson, Olivetti, Cromemco, Heath, Kaypro,
Osborne, Apple, Ericsson, Avatar, Compugraphic, Liberty,
Generic Televideo and others
Most teams these terminals compatible with each other. But
almost everywhere there are small differences. The situation is
similar to the standard matrix Printer firm Epson: Many
companies produce similar printers, virtually repeating the
command system Epson'a, but to support their own "bloat", add
their own commands or extend existing ones. All of them are
compatible with Epson'om, but not with each other. C terminal
situation is almost the same, except that one terminal, in
principle, can support multiple systems are not mutually
konfilktuyuschih commands. For example, the team VT-100
terminals or ANSI codes begin with ESC, '[' (1Bh, 5Bh) and so
way, does not intersect with teams of other terminals, so they
can along with their support team and VT-100.
In addition to the above-mentioned terminals exist
More and pseudo-TTY, ie operation mode TTY: symbol is printed
at the current cursor and processed only a few control codes.
Team supports any TTY terminal (a also present TTY). Thus, the
programmers in the CP / M to create the program had a choice:
or write it to a specific terminal or only use the "terminal"
TTY. In the first case, the program will only work on
compatible terminals in the second - on any computer. Are
program as the first (eg, SuperCalc), and the second type
(DD80). "Smarter" programs have configuration utility (setup or
install), that asks the user what he or terminal what his
computer, and then writes the configuration files and the
program worked perfectly.
Now let us consider some of the instruction
terminals.
TTY TERMINAL
Terminal identification name: "TTY"
Screen length default: 25 lines
Auto-wrap: OFF
Print mode teletype. Allows you to print plain text in a
standard encoded ASCII. Characters with code less than 20h do
the following:
^ G [07] sound (bell or beep)
^ H [08] backspace (backspace)
^ I [09] tabulation, ie, move the cursor to the column,
multiple of 8
^ J [0A] newline (linefeed)
^ L [0C] clear screen (clear screen)
^ M [OD] carriage return (carriage return)
VT52 TERMINAL
Terminal identification name: "VT52"
Screen length default: 24 lines
Auto-wrap default: ON
The terminal can print plain text
standard encoding ASCII. By default, symbols
displays with high brightness (bright), but you can switch to a
low glow characters (dim). The screen can be displayed
simultaneously both bright and dull characters. Also The
installation of the absolute values of brightness (64 level).
Characters with code less than 20h do the following:
^ A [01] the cursor in the upper left-hand familiarity (home
cursor)
^ B [02] and low brightness mode symbol (dim mode)
^ D [04] clear screen and cursor positioning
(0,0 - home)
^ G [07] sound (beep)
^ H [08] backspace (backspace)
^ I [09] tabulation, ie, move the cursor to the column,
multiple of 8
^ J [0A] newline (linefeed)
^ K [0B] move the cursor to the position up (cur
sor up)
^ L [0C] clear screen (clear screen)
^ M [OD] carriage return (carriage return)
^ X [18] treatment to end of line (clear to end of
line)
^ Z [1A] is similar to ^ D
ESC [1B] control (iskeyp) sequence
^ ^ [1E] ^ A similar
^ _ [1F] carriage return and linefeed
Cursor control is carried out by a sequence: ESCAPE, 'Y',
string +20 h, +20 h. Column Or ESCAPE, string +80 h, +80 h.
Column Origin in upper left corner (home). Others ESC-sequence:
([28] The following characters are vivid (go to
bright mode)
) [29] The following characters are dim (go to
dim mode)
* [2A] clear screen (clear screen)
+ [2B] clear screen
, [2C] clear screen
: [3A] clear screen
; [3B] clear screen
A [41] cursor up (cursor up)
B [42] cursor down (cursor down)
C [43] cursor right (cursor right)
D [44] cursor left (cursor left)
E [45] clear screen and home cursor (Only clear
screen for Amstrad.)
H [48] home cursor
I [49] back pervod string (reverse linefeed)
J [4A] treatment until the end of the screen (delete to end of
screen)
K [4B] treatment to end of line (clear to end of
line)
L [4C] insertion line (insert line)
M [4D] deleting a row (delete line)
R [52] delete the line (delete line)
X Set the size of the output window (Set text
viewport):
TR, LC, H, W
TR = Row top of viewport +32
LC = Left column +32
H = height (rows-1) 32
W = Width as above.
Y [59] control the cursor position;
b Set the brightness of characters (foreground):
C = 63d or 0d. 1963 is bright, 0 is dark
c Set the brightness of the background (background):
similarly 0-darkest ... 63-the brightest.
d [64] clear from start of screen to the cursor
position
e [65] to include the cursor (cursor on)
f [66], turn off the cursor (cursor off)
j [6A] to save the cursor position (save cursor)
k [6B] to restore the previously saved position
cursor.
l [6C] cleaning line (clear line)
o [6D] cleaning the screen from beginning to the current row
ki
p [70] inverted the characters (go to reverse mode)
q [71] the normal characters (cancel reverse mode)
v [76] wrapping turn (turn line wrap on)
w [77] wrapping off (turn line wrap off)
* TO BE CONTINUED *
on)
w [77] wrapping off (turn line wrap off)
* TO BE CONTINUED *
and
relatively simple) is specially programmed
for each machine with regard to its hardware features. This
part of the system created by the producers themselves PC. Thus
it turns out that the CP / M compatible with most 8-bit
computers.
It is a broad system compatibility, as well as several
other features, such as support for transit or external
command, made her so popular.
* TO BE CONTINUED *
ranzitnyh or external command, made her
so popular.
* TO BE CONTINUED *
(C) Chertkov VY
Music: APPLE on PLATE / KENOTRON 96
STUDIES CP / M
Part 5
GENERIC TELEVIDEO 912/LIBERTY/MORROW/ADM /
GENERIC LEAR TERMINAL
These terminals have a lot in common, so
below summarizes the command system, ie some
commands are the same type of terminals, the other - to
another, some teams can match.
For these terminals, most applications written for CP / M.
Differences between terminals are in the number of rows and on
/ off. regime AUTOWRAP.
The terminals allow you to print plain text
in the standard encoding ASCII. If the cursor is moved beyond
the last row, then made movie screen up one row and the last
row is cleared (auto scroll). Output symbols can be individual
attributes (brightness, underline, inverse, flashing).
First, distinctive features:
Terminal identification name: "ADM 3A"
"Morrow MT70"
"Televideo 912"
Screen length default: 25 lines
Auto-wrap default: ON
Terminal identification name: "GENERIC TELEVIDEO"
"LIBERTY"
Screen length default: 24 lines
Auto-wrap default: ON
Terminal identification name: "GENERIC LEAR
SIEGLER "
Screen length default: 24 lines
Auto-wrap default: OFF
Terminal identification name: "MORROW MDT20"
Screen length default: 24 lines
Auto-wrap default: ON
About the emulation:
The main difference lies in the fact that
opposite to the sequence of control cursor
(ESC ,=,...) necessary to swap the coordinates
cursor (ie, first set the column number, and then
line).
Proper system of command above the Terminal. Characters
with code less than 20h do the following:
^ A [01] The following characters are bright (bright
mode)
^ B [02] The following characters are dim (dim
mode)
^ D [04] clear screen and home cursor
^ G [07] beep
^ H [08] backspace
^ I [09] TAB
^ J [0A] linefeed
^ K [0B] cursor up
^ L [0C] cursor right
^ M [OD] carriage return
^ X [18] clear to end of line
^ Z [1A] clear screen and home cursor
ESC [1B]
^ ^ [1E] home cursor
^ _ [1F] carriage return and linefeed
Cursor control is carried out by a sequence: ESCAPE ,'=',
Row +20 h, Column +20 h (Row - Line, Column - column). Ie, the
value of the coordinates is necessary to add 20h (code space),
otherwise the code is run for the team, not as a parameter
functions ESC ,'='!. In the derivation of the character with
code 27 (1Bh) following characters mean:
"[22] cursor type
ESC, ", n where n - is:
[1B, 22, nn]
Block 0
1 Block
2 Block
3 Underline (Underline)
4 Underline (Underline)
5 Underline (Underline)
6 No cursor
([28] go to bright mode
) [29] go to dim mode
* [2A] clear screen
+ [2B] clear screen
, [2C] clear screen
. [2E] cursor control
ESC,., N where n - is:
[1B, 2E, nn]
1 Cursor off
3 Cursor on
: [3A] clear screen
; [3B] cursor control
ESC,;, n where n - is:
[1B, 3B, nn]
A Cursor off
I Cursor on
= [3D] cursor movement control (upr.kursorom)
A [41] cursor up
B [42] On. attributes (attributes on)
ESC, B, n where n - is:
[1B, 42, nn]
0 Inverse (inverse)
1 Bright (Bright)
2 Blink (Shimmering)
4 Cursor on
C [43] Off. attributes (attributes off)
ESC, C, n where n - is:
[1B, 43, nn]
0 Inverse (inverse)
1 Bright (Bright)
2 Blink (Shimmering)
4 Cursor on
D [44] to delete the character (delete character)
E [45] insertion line (insert line)
G [47] Set attributes for the next symbol
oxen (set display attributes)
ESC, G, n where n - is:
[1B, 47, nn]
0 Normal (normal characters)
1 Underline (underline)
2 Dim (dark)
4 Reverse (inverse)
8 Blink (blinking)
These attributes can be set at the same time, it needs to
lay down appropriate values.
Appointment of the following command was not clear:
what kind of graphics mode is it?
H [48] graphics mode control (Simp. graphical solution
zhimom)
ESC, H, n where n - is:
[1B, 48, nn]
2 graphics mode on (graphic dir. Incl.)
otherwise the graphics mode off (graf.rezh.vykl.)
I [49] go to reverse mode
J [4A] delete to end of screen
K [4B] clear line
L [4C] insert line
M [4D] delete line
N [4E] cancel reverse mode
Q [51] insert character
R [52] delete line
T [54] delete to end of line
W [57] delete character
Y [59] delete to end of screen
d [1964] cursor on / off
ESC, d, n where n - is:
[1B, 64, nn]
0 cursor on
otherwise, cursor off
e [1965] cursor on
f [66] cursor off
i [69] back TAB (reverse tab)
j [6A] save cursor (save cursor position)
k [6B] restore previously saved cursor position.
(Recovery rate of the stored position.)
l [6C] go to bright mode
m [6D] go to dim mode
q [71] insert character (insert character)
r [72] delete line (delete line)
t [74] delete to end of line (delete to the end
line)
w [77] delete character (delete character)
y [79] delete to end of screen (to remove the end
screen)
VT100 TERMINAL
Terminal identification name: "VT100"
Screen length default: 24 lines
Auto-wrap default: ON
The terminal can print plain text
standard encoding ASCII, control the color output of characters
and the shape of the cursor.
All teams start with a sequence ANSI/VT100 ESC, '[' (1Bh,
5Bh), followed by the options. Thus, the team VT100 do not
intersect with teams of other terminals. Parameters are given
in the form: P1; P2 ;...; Pn; C - where P1 and P2 to Pn -
decimals (if none, then it is assumed that it is zero). Symbol
C denotes one-letter command - the symbol of ASCII:
A [41] Cursor up. P1 specifies the number of rows to ne
displacements up. P1 value of 0 is equivalent to
valence 1. Upon reaching the top row
command does nothing.
B [42] Cursor down. P1 specifies the number of rows to transfer
displaced downwards (+ see above)
C [43] Cursor right. P1 specifies the number of columns for
move to the right (+ see above).
D [44] Cursor left. P1 zadaey number of columns for ne
displacements to the left (+ see above).
H [48] Cursor positioning. P1 sets the string, and P2 -
column. Upper left corner has coordinates
You 1,1. Any parameter equal to 0, is
equal to 1.
J [4A] Erase screen. P1 can be 0, 1 or 2.
P1 = 0 - cleaning of the cursor to the end of the screen,
P1 = 1 - cleaning the screen from beginning to cursor
P1 = 2 - clearing the screen.
K [4B] Erase line. P1 can be 0, 1 or 2.
P1 = 0 - cleaning from cursor to end of line
P1 = 1 - clean from the start line before the cursor
P1 = 2 - clearing entire rows.
P [50] Delete character. P1 - number removed sim
ox. If P1 = 0, removes the first character.
f [1966] Cursor Positioning. See H [48].
h [68] Set mode. Ignored.
l [6E] Reset mode. Ignored.
m [6D] Select video attributes. P1 contains the attribute
which will be added to the current.
P1 can be:
0 - clear all attributes,
1 - bright,
4 - underline,
5 - blinking,
7 - reverse.
s [73] Save cursor position.
u [75] Restore cursor position.
In a more modern computer terminals
are no longer used, because have several disadvantages:
character by character printing (bring a string of characters
for one can not appeal), speed limit display characteristics
interface (after all characters are transmitted by cable is not
instantaneous), it is impossible read characters on the screen,
and finally the impossibility of working with graphics. To
replace the terminals came adapters, but the display drivers in
the system CP / M, as a rule, teams emulate terminals.
Thus, even if the characters on the show
screen only through BDOS or BIOS, it is possible to control the
color of characters and the cursor position, etc. The program,
operating through driver, of course, more mobile - it's easy to
transfer to another PC.
Driver profiles are supported on the screen of
teams VT52 (why not all - it must ask
its author), the other part was taken from the ceiling
(Or, rather, developed from scratch). Naturally, these
"New" command does not understand a single Western CP / M
program.
* CONTINUED IN THE NEXT ISSUE *
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В этот день... 21 November