ZX Review #11-12 26 ноября 1997

Authoring - S. Zonov, A. Larchenko. On the controller SMUC (HDD IBM and peripherals).

     Authoring



Music by ZET

S. Zonov, A. Larchenko


       About the controller SMUC

     (HDD and IBM-periphery)


   This article is from
a concise description of the development firm Scorpio (St. 
Petersburg) - the controller SMUC. C moment of receipt of the 
controller on the market have passed more than a year, interest 
is growing, both with of computer users Scorpion, and from the

users of other Spectrumsovmestimyh computers. The fact
how to modify your computer
to be compatible with Scorpio,
described in detail in the journal ZX
REVIEW N 7-8, 1996. Purpose
This article - more clearly
acquaint readers with the fact that
it represents the controller
SMUC, as it connects to your computer as it happens through the 
connection of the hard disk how is work hard

disk in the system TR DOS and IS
DOS, although in the latter system
work with the HDD almost anything
no different from working with electronic drive (usually drive 
C). 


     APPOINTMENT OF CONTROLLER


   The controller is designed SMUC
Connectivity
Scorpion ZS-256 (or any Spectrum-compatible PC):

   - Hard drives (HDD), equipped with interface IDE, and allows 
you to work with them in systems TR DOS, IS DOS,

CP / M;

   - A variety of peripheral
cards from the computer IBM PC XT,
such as, for example, Hayes-modem transfer rates from 1200
up to 14400 Kbps, sound cards
different types of programmers and
many other IBM-compatible
device.


   In addition, the controller is equipped with a chip 
nonvolatile memory (NVRAM) of 2 KB designed to save different 
settings on your computer, parameters HDD, variables Shadow 
Service-monitors, etc. The controller provides the installation 
of chip nonvolatile hours (such as

M146818, DS1287, DS12887, 512VI1)
and interrupt controller i8259
or 1810VN59a (standard
supply of these devices are not
installed).

   For the most successful and
productive work computer is desirable to connect the controller 
to the computer Scorpion ZS 256 Turbo +, although

possible and the controller
neturbirovannymi with computers
Scorpion 256, as well as other
Spectrum-compatible computers (if the necessary modifications). 
Software support for the controller is in Professional ROM 
(ProfPZU) Computer Scorpion (ProfPZU volume - from 128 KB to 
512 KB). The firm has redesigned the Scorpion and the contents 
of EEPROM, starting with version 4.0, an opportunity to work on 
different versions of Spectrum-compatible computers. 

   Structurally, the controller is the PCB size 102x72 mm.

   Supply current controller
no more than 300 mA.


        Setting the clock
 real time (CMOS-hours)

    and interrupt controller


   The standard version comes without SMUCkontroller chip Real 
Time Clock (MC146818) and chip interrupt controller (i8259a), 
but desired user needs

just insert these chips in
appropriate sockets on the controller board. All necessary
for these chips to
controller board provides
including nonvolatile
clock pulse for
hours, and the circuit switching to
backup power.

   MC146818 chip can
be replaced by a Soviet analogue - 512VI1, as well as other 
imported chips firmproizvoditeley. All of them have the same 
building at 24 O and can differ only in name. To ensure the 
work of real-time clock for the period turn off the computer, 
you must use a source of backup power supply +5 volts, which is 
connected through a connector X7. The current requirement from 
this source - microampere share, so you can

use any suitable
battery. In addition, the IC socket for hours, you can insert 
IC firms Dallas - DS1287 and DS12887. These devices already 
have built-in pulse generator and a source of backup power. 
Manufacturer's guarantee reliable operation of power for 10 
years. When using these chips an additional source that is 
connected through a connector X7, is not required. It should be 
remembered that the presence or absence of IC clock does not 
affect the operation of the controller from the HDD. All plants 
HDD parameters and other variables used by the Shadow Service 
Monitor, and appointed the user is stored in IC

nonvolatile memory (NVRAM), installed at all
controllers. No additional sources for
NVRAM is not required.


   Chip interrupt controller when using the HDD is not 
currently used, and its absence does not affect the

operation of the controller. It is designed primarily for work 
with a different IBM-periphery For example HAYE's modems. Can

use IMS i8259A, or Soviet equivalent 1810VN59A. Not recommended 
to use the chip 580VN59. 


           Requirements

      to power supply


   The controller uses a
little current from the source
computer power and, as a rule, does not require "empowering" 
the latter. But the drive HDD, especially if it is sufficiently

"Ancient", can consume significant current as of +5 V, and
to +12 V (2-3 A mode
normal operation and even more in
the time of launch). Therefore, make sure that the source of 
"provides" the necessary voltage: +5 V +5%, +12 V, +5%, 
otherwise it should be replaced power supply to the more 
powerful. When the source should also bear in mind that if you 
plan to connect the IBM-board peripherals, it is necessary for 
them to lay the power reserve. For the calculations can be 
tentatively assumed that the current consumption of additional 
sources supply the following: +5 V - 1,5

A, -5 V, -12 V, +12 V - 0,5
A.


    Hard disk drive


   Perhaps the most important and
anticipated fixture on the
universal controller peripherals SMUC is IDEinterfeys hard 
drive. This interface allows you to simultaneously connect to 
two devices and to date this

popular interface provided with not only hard drives, but also
some other device,
For example, disk drives, CD ROM.
The software is designed until the Shadow Monitor
only one service
hard drive, but the hardware
SMUC controller provides all the
interface capabilities IDE, implementation of which, naturally,
will be implemented in the future.

   This section describes the work
with a hard disk connected to the
controller SMUC. Actually,
Work a little harder to drive than a floppy disk and drive, and 
perhaps the main difference is the "tenure" "Floppy" and an 
order of magnitude larger its volume.



   Begin work necessary
naturally, connect the hard disk ("insert a floppy disk). Then 
you need to define the parameters of the device (remember, as 
you would with a diskette TR-DOS first tries to determine its 
size - number of tracks and parties). However, unlike

drive, the procedure for
hard drive is slightly more complicated, but it should be done
only once. At this stage
connection ends, and
need to partition your hard drive - that is to create 
information structures, divided large amount of disk space on 
terms acceptable to work part. Just say - the concept of 
"formatting" Hard Drive with IDE interface is absent, these 
devices come preformatted from the factory and more in

his "life" never format is not
change. And finally - the actual work with the data on your 
hard drive. 


   The order of presentation of the material in
This section is designed so that you as quickly as possible, 
and at the same time, correctly and consistently, including 
drives to work. 


   Installing a hard disk


   Installing a hard disk
IDE interface consists of three
main phases: hard-wired connection, the software identification 
and testing of the disk. 


   Hardware Connection HDD


   Hardware connection devices, perhaps the simplest and most
At the same time the most responsible action. When errors can 
result from the failure not only hard disk drive and controller

and a computer. So be
very attentive.


   SMUC controller is inserted into the
plug the computer's motherboard, so
to the details of the controller to look on the details the 
board. The controller connects to the hard drive, a special 
40-wire ribbon cable so that a contact coincided on the 
controller, and hard drive (on cable extreme

wire, corresponding to a contact, usually marked).
Power is supplied to the hard drive
through a special connector, similar to the same on the drive.

   After all connections can be
turn the power on, and on the computer screen should appear 
immediately familiar inscription "fast test of computer "(in 
the past versions of the TM first appears

inscription on copyrights), and
on several reports found (or not found) device controller SMUC. 
After power-up hard drives various manufacturers and models are

themselves differently. But the characteristic
is small (less than a second) pause, then the sound of aircraft 
taking off in a miniature (a contemporary models, he almost did 
not heard), this promotion engine disks themselves 
("pancakes"). Then, the "recalibration" and internal testing of 
the mechanism of magnetic heads, expressed in the lung (as in 
old models - rather loudly)

"Pohryukivanii. The entire operation
The self-test occurs at
Each power (and
By the way, regardless of the connection to the controller), 
and lasts from 5-10 to 30 seconds.


   If after switching voltage hard drive "silent", then
or it is not enough power supply (it can be verified by 
measuring tester +5 V and +12 V) or incorrectly (reversed) 
connected to the cable connecting the hard drive and 
controller. Insufficient power supply can cause unstable

of the drive (this is especially true for older models that may 
consume a pulse current up to several amperes to 12 volts, 
compared to - new, modern hard drives

may consume less than floppy disks).

   Now look at the screen.
If, despite "attempts to" the hard disk on the screen at once
appears on "Hard disk
not found ", then again, most likely" upside down "cable
or enough power for the hard disk interface (interface part of 
any hard disk usually works even when self-test detecting 
errors and reports them controller). It is possible, however,

complete loss of all
electronics of the disk.


    Software Connection


   If the interface part is in order, during the process of 
self-test HDD Computer "hangs", waiting

"Response" from the device, and after
receiving this reply, trying to
determine the parameters of the disc. For
obtaining these parameters is a special procedure
which also takes some time. Total time when you first start 
your hard drive, exceed several minutes. If this time is 
longer, the disc is not in order. 

   Successfully identified the hard
disk, it displays the computer
inscription form "IDE / AT 42 MB Hard
disk found ", where instead of the number 42
will stand a certain amount of software on your hard drive. If
this volume does not correspond to the actual volume of the 
disc, then this disc correctly identifies itself to the program 
and requires manual adjustment of parameters of

than just below. Next output
three lines with information firmyproizvoditelya. The first line
usually contains a meaningful name of the firm or the model, two
others - the serial number and date
production model, but each
manufacturer is free to enter,
what he wants. The monitor does not provide any delay
examining these inscriptions,
if you are still interested, press (and hold) the "Reset", but 
after This necessarily produce

"Cold" start computer
(Discharge from confined to the keyboard by pressing "Left").

   If the internal tests and Auto identification HDD
were successful, then the computer goes to standard menu 
running BASIC. Further action by connecting the hard drive 
should be carried out in the Shadow Monitor (remember that the 
entrance to the TM by short-term

pressing the Magic).

   If you have an old and slow drive, then perhaps it is not
have time to do all the internal

tests at the time of checking its
home monitor program, in
this case on the computer screen instead of the above posts 
there any error message (most likely "Hard disk data not ready" 
or "Busy not found"). In this case, try not turning off the 
power to make a second "cold" start your computer. If it does 
not help (still receive error messages), then check your 
hardware connection of the controller and SMUC

hard drive. It is possible that with
so drive instance requires manual setting of parameters, or it 
will not work in general.



  Automatic Identification


   Thus, we have the menu of the Shadow Service Monitor. Select 
item menu "Hard disk utility", and

It "Set Up".

   As the name implies, automatic identification of the hard 
disk automatically. Actually, the first automatic 
identification has occurred (see previous section). Or at least 
trying to happen. Results process are shown in paragraphs

menu, Cylinders, Head and Sector,
which show the "geometrical" parameters of the hard disk
respectively, the number of cylinders,
heads and sectors. These options should ideally be
comply with the passport hard disk parameters. You can again, 
"just in case" perform the procedure Autoconfiguration hard 
drive by selecting "Auto detection hard disk "." Geometric 
"sizes should remain stable and

unchanged.

   So, if everything is in order,
data coincide with those found
these expectations, then we can
allow for the identification of
start (it is enabled by default, the menu item "on start" in
state ON), and go directly to a hard test
disc. Otherwise, go to manual identification
disc.


   Manual tuning of parameters


   Actually, you should enter
menu items "Hard disk utility / Set Up" real "geometrical" size 
of your hard disc. This is the number of cylinders, heads and 
sectors. These parameters sometimes lead to the body of the 
disks themselves, if they do not, contact the dealer to foist 
you is a miracle. 

   Is that the parameters read from the hard drive is not
untrue,
although by all indications Auto identification was (quickly 
and without errors).


   So, you entered the real parameters of the hard disk. Now
care must be taken to
starting the monitor is not
Auto identification carried out at
"Cold" reset the computer.
To do this, move the item "on
start "to OFF.


           Conservation

      settings


   Any changes in the parameters
Menu Shadow Service Monitor
valid only until the power is turned off, or "cold"
Reset the computer. Then
all restored to the state "by default". This fully applies to 
the parameters hard drive and as a trigger "on start". However, 
not all so sad. The controller

SMUC a chip nonvolatile memory, which
able to store part of the vital
important variables of the Monitor and
restore them as soon as
power. However, record those variables into memory
you must manually.

   Exit to the main menu, Service Monitor ("Main menu"), then 
select the submenu "Set Up", and there submenu "Monitor". Now

select "Save CMOS". All
you make to settings will be stored in nonvolatile memory chip
(NVRAM), which is installed on
all manufactured controllers.


   Testing of the hard disk


   After the automatic, and so
a manual identification of the hard disk, you need to check how 
the drive will work with established by the "geometric"

sizes. For this purpose, the submenu
Set Up menu, Hard disk utility
You can choose two tests, the first
(Denoted by the numeral 1) is designed to test circuit 
broadcast sectors in hard drive and to identify unreliable

sectors. In addition, the test allows you to visually estimate 
the speed of the hard drive because it uses real driver 
routines, "wired" in ROM Shadow Monitor. Second

test (indicated by the numeral 2) is more lengthy and 
complicated. It allows you to check the data transfer 
mechanism, ie the circuit IDE "in the enhanced mode.


   Let us work tests. The first test is just a series
reads all sectors on the hard disk. Content Checking
sector is impossible, and to assess the error test is satisfied
messages issued by a hard disk. On the computer screen 
displayed the current counter checked the cylinder and "running 
a stick, some quickening now, you can interrupt the test by 
pressing the BREAK. Actually, If "all good", then this case

and limited - the counter doschityvaet to the maximum of the 
cylinder, the screen is given the coordinate of the last read 
sector, and the test is completed. Can proceed to the second 
test. 

   In the case of fixing errors
on the screen a message is displayed on the
it, which presents
coordinate of the bad sector (number of cylinders, heads and 
sectors) and the type of error. It should be pay attention to 
the "frequency" errors. If they are few and they happen 
randomly, it is likely all, this instance of a hard disk fails, 
and then to work with him is not recommended. If the error is 
"Groups", with alternation of certain numbers, for example, 
read the sector, starting with some definite numbers on All 
heads, or on all cylinders is a mistake, starting with a 
specific head, then, it is likely that the hard drive are 
incorrect "Geometrical" dimensions. It happens that on the disk 
"crashes" some one head, and all sectors, it has read, are 
"beaten". In these cases you must return to the manual setting 
of parameters and try "Cut off" faulty, reducing

appropriate values. After
Why spend a re-test.

   The second test is more
informative but also more dangerous. Its algorithm is as 
follows - from the sector is read out located

there information, then the sector is written pseudo code, 
after which new information is read and checked against 
written, well into the sector returns to its former value. Such 
an operation is performed for All sectors on the hard disk.

As can be seen, the test is not only relies on diagnostic errors
issued by the disk, but
objectively verify the quality of
channel read / write. Why
test is dangerous - obviously. If
there are write errors, then the sector can not go back you had 
before the operation value to the same unexpected interruption 
of the test (power off, manual or any discharge

computer) can lead to
similar effect. Therefore, first, a second test after a 
successful passage of the first and second interrupts the 
passage of the test only on command from the keyboard BREAK. 

   Indication, which is issued to the screen, similar to the 
first test. Just the same steps in

If mistakes - try to "close" bad sectors or heads manually 
specifying the appropriate parameters. 

   Some remarks on the management of error messages: you can 
suspend the conclusion of the text (and test) by pressing press 
SPACE, in this state cancellation of further transmission

test - a key EDIT / C, as well
ENTER key continues to test.

   At the end stage of testing, connect the hard
disc, now need to create
logical structure for data storage.


           Creation

    Information sections


   As for the floppy disk, hard disk space you need to create
something like a directory of information which will help the 
operating system is on it the files. However, the structure of 
such a catalog is much more complicated than for floppy disk. 
Firstly, comparable volumes, stored on a floppy disk and hard 
drive, and secondly, I would like to be able to run multiple 
operating systems and even in different "Classes" of computers 
within a single disk (good amount of disk space is quite 
allows). 

   Why use multiple systems? This issue should not be 
considered here, but briefly, we note that none of the existing 
on ZX Spectrum disk systems did not cover the full

least of all the interests of all users. TR DOS became the de 
facto "General" system, including

to store game programs,
Is DOS - a system for record keeping, Micro DOS - the best
means for the programmer, etc.
In addition, it is possible to combine the use of the same hard 
drive on ZX Spectrum and, say, an IBM PC. For combining all of 
these requirements was developed by the storage format

data, which is sufficient
has been supported Shadow
Monitor.


   Global Partition Table

             (MBR)


   First of all, you need to restrict access to the hard drive 
from the ZX Spectrum, and, if necessary, running on other 
computers. To this end, the disk is created so-called home MBR 
(Master Boot Record, MBR), and in her home

partition table (Global Partition Table, GPT). The idea is this:
one section - one system.

   In sub-Hard disk utility
Select Partition manager
and enter the partition editor.
Pay attention to names
submenu, it must be "Global
partition manager ", if you
hit the "Local partition manager", it means that the
hard disk has been used
on the ZX Spectrum, and the MBR is created.
Look at your current home
partition table, click
Partition information.

   This will display a table
which is displayed on the right type
section, and the left - the volume of the partition in 
megabytes. Renounce You can view a table, using the key EDIT / 
C. 


   Type Unused means "empty"
site (free entry in the table do not correspond to any
type). If your drive is not new,
it is likely that the entire volume will be divided into 
several (or a) MS DOS partition or other. Use the Delete 
partition point for you to remove unwanted sections (move the 
screen cursor to a busy recording and press ENTER). 

   Now you can start
creation of a special "Spectrum" section. Select
click Create partition ..., appeared in a familiar table, 
select the line Unused, press press ENTER. Edit,

if necessary, the number on the right
of the line. As already mentioned, this number specifies the 
amount of new partition. If you work with other computers is not

assumed, then leave the number unchanged. Press again
to press ENTER. The table will be created a section called
MFS and the specified volume. Item
Create partition ... can only create a partition MFS, to create 
other types of partitions must use the appropriate software 
other operating systems. 

   If you intend to work
with multiple computers, then
You can "break" hard drive
standard means, for example,
on the IBM PC, for example program
fdisk, leaving the partition MFS
desired location.

   A few comments. Spectrum section of MFS can be
only one. Several sections
MFS allowed for future extensions of the system, but at present
time work is only
first of them. In total, the main
partition table can contain up to four entries.

   Note that all actions
edit partition table
happening in the computer memory
You can delete and create partition as you like, but in order
that the information got on the disc,
must select Write
to disk. And only after the confirmation key (Y)
primary partition table will be
recorded. Item Restore from
disk to copy to
computer memory in the current table from the disk. If you 
change anything, while in sub-editor, then when you try to exit 
from the submenu you will be asked or write the changes (it is 
yet again the key Y), or to refuse of change and leave 
everything as it (any other key).


   Serious about changing the partition table, because
changing the format of the table violate the existing links and 
leads to loss of previously contained on the hard disk 
information. Note that we say nothing about the maximum

size for the partition
MFS. Indeed, its size is almost unrestricted. While the Shadow 
Monitor can have access to a volume of about 1800

MB, the amount of the section may be
more, but the "extra" part simply wasted.

   Once the partition is created MFS
in the main partition table in
submenu Global partition table
"Open" paragraph Local partition table. By selecting this option
you will fall into a similar sub-
editor of the local chapters or
subsections.
 Local table (sub) partition


   Created in the main table
"Spectrum" section of MFS,
should, in turn, be
divided into one (but, rather,
multiple) subkeys. Each
Subpart able to "carry" their
operating system in the ZX
Spectrum. In the current version of the Shadow Monitor provides 
the following types of operating systems: TR-DOS, Micro DOS, 
IsDOS. COMING SOON possible addition of other systems, if need 
be. I note that only the TR-DOS yet fully supported

embedded software Shadow Service Monitor.
For the rest of the OS should be the appropriate drivers in 
these OS. 

   Immediately note the restriction
Section MFS - it may contain
up to 63 different sub-sections,
up to 32 MB each. In addition to type, different topics
names, you can create multiple
subsections of the same type, but with
different names. Name length
not more than six characters.


        Collection of disks

       (Sub-TR-DOS)


   The most important (and difficult)
feature of the embedded software is
attempt to emulate the hard drive disk-TR-DOS. In
Due to various circumstances, and despite the glaring errors 
and shortcomings, this is the system has become the most common

for Spectrum-compatible computers in our country. Therefore,
namely the OS from the start
work is paid the most attention.

   When comparing the amount of disk,
which is oriented TR-DOS,
and the volume of sub-section on the hard
drive, catches the eye
inadequacy of official information in the directory disk. 
Directory was not designed for long volumes. Trying to somehow 
change system itself, "adjust" its parameters to the hard drive 
inevitably would lead to the incompatibility of new and old 
versions, and in eventually - just a new

operating system, and with
deliberately poor performance. Not trying to resuscitate
TR-DOS, the Shadow Monitor, while at the same
time makes it possible to use the hard drive to work
the old system.

   The idea is very simple -
hard drive is a
collection psevdodisket format
which corresponds exactly to a floppy. Special
tools allow you to "embed"
such a floppy disk in the "normal" drives, and TR-DOS did not 
even realize that working with the emulator. Direct the work of 
dedicated integral part of the description here

We show you how to create a collection of ramdisk (subsections
TR-DOS).

   First you need to create a sub-TR-DOS. Select
Create partition ... (Recall
this should be done in the submenu
Local partition manager). Move the cursor to the line that says
Unused (initially the only
line), then press ENTER.
The line appears TR-DOS
- Again, press ENTER. Now
must enter the name of the subkey. This name will later
used for access to the stored in subsection ramdisk. It can 
contain up to 6 characters. Fix a name to press Enter. Finally,

must choose the amount of sub-section - enter a number equal to 
the ramdisk contained in this section. The minimum number of 
drives - one, maximum - 51 (of course,

if you have enough free space in
this subsection). By default the maximum
possible in this section
number. Fix the number of
ramdisk - press the ENTER.

   In contrast to the global partition table, keep in mind all 
the changes related to the local table

troublesome, so the program immediately offered to make changes 
to your hard drive. In the case of yes (key

Y) will be made counting
respective subsection, that
It may take some time. By
After marking management
return to the editor of the local
subsections.

   You can create multiple collections ramdisk, it is important 
only to the names they were different. Take into account one 
circumstance. Collection ramdisk can be removed so same as in 
the global section table (just like any other subsection, 
paragraph Delete partition ...), but only as a whole. Current 
software does not provides for a decrease / increase the size 
of sub-section. Now being developed program Support hard drive 
of some functions of the Shadow Monitor will require the hard 
drive of a number of memory (Planned to 3-5 MB). Most likely, 
the type used subsection would be

Micro DOS. It is therefore recommended to leave a few megabytes
unoccupied (Unused), in order
that subsequently did not have
repartition the entire hard drive.

 The topics in operating systems


   Creating a sub IsDOS and
Micro DOS does not significantly
differs from the creation of sub-TR-DOS. Select Create
partition ..., move the cursor to
free sub-section (Unused),
then press ENTER. Key
SPACE to select the desired style,
fix the choice of key
ENTER. Then enter the name of subsection (not more than six 
characters) fix the name, and finally,

specify the amount of sub-section, in kilobytes. Volume 
subsection shall not be less than 256 KB or 32 MB (or more 
precisely 32,767 KB). As for the sub-TR-DOS,

You can create several sub-sections with one type of operating 
system, but different names. 

   Created a subsection - is
emphasis (reserved) seat for the selected OS
on the hard disk. For real
the OS driver is required, written under the OS. In ROM
have all the necessary tools (RST 8 calls) to maintain such a 
driver. There is no doubt that soon drivers will be written for

both systems. For the system ISDOS
this driver is written by us. For details, see the section 
"Working with hard drive for ISDOS ".



    Work Hard Disk

          for TR-DOS


   As already mentioned, the work
hard disk in the system
TR-DOS does not differ from that of the real
diskettes.


    Virtual and physical

           Drives


   Hardware and operating system support TR-DOS (Beta Disk
Interface) has historically maintained for up to four 
real-world drives. In the system, they are denoted by A, B, C 
and D, respectively. Really well connected one, maximum two 
drives, the devices C and D, as it were disappear. It was 
originally planned on these unused characters designate by hard 
disk psevdodiskety. These drives become virtual - for TR-DOS 
they are, and for their Beta Disk Interface

no. However, it turned out to be possible (for consistency) to 
provide the opportunity for All four devices.


   But the question arose - how to tell the system that, say, 
drive B is now a physical (if it is connected to a computer) 
and not virtual, and vice versa? To exit this situation, the 
concept of Communications and drive image

diskette to your hard drive. If
link is established - the drive is virtual, and when it 
receives a choice of physical drive is not happening. If

there is no connection - a physical drive.


   Connecting the floppy image


   Establishing a connection between the device and ramdisk is 
carried out in sub-Hard disk utility. For each device

there is a point Mount (mount,
connected), followed by the name of the virtual drive. This 
choice leads to appear on the screen of the current table of 
local chapters. From it need to select any

collection ramdisk (choice
is fixed by pressing
ENTER). After the appearance of the catalog collection, move 
the cursor to the appropriate drive, and fix a choice.


   The name of the selected (connected) ramdisk appear in a row 
Mount. The name of the compound, the first is the name of the 
collection (sub- TR-DOS), and by the character '\' should be 
the name of the disk image. 

   Now, any appeal from
TR-DOS or from the monitor to the appropriate virtual disk 
drive will be "sent" to your hard drive. You can "format" 
ramdisk (better to choose "Quick" formatting in Disk Utility 
menu item Quick format disk), and copied to

virtual disk files with a real disk.

   The current target is automatically stored on the hard
disk and restored when
"Cold" start your computer.

Disconnecting from a virtual drive


   If you want to break
connection between the device name
TR-DOS and ramdisk on a hard disk, for example, to restore the 
physical drive B, you must select Dismount ... in submenu Hard 
disk utility. When All the items are replaced by Mount

to Dismount. Select an item
corresponding to the required drive
For example Dismount B. All items
Dismount again "turn" in
Mount, but the selected item disappears name ramdisk.


       Features of

      to monitor and TR-DOS


   So, your hard disk,
making it sub-structure and collections related ramdisk and 
floppy drive, thus create a virtual disk, you can proceed to a 
normal daily work. Now let's talk about some of the features of 
this work. 

   Prepare to be that some small portion of programs previously 
more or less worked with floppies TR-DOS, now will not work. 
This is true, mainly to the old programs,

who do not take into account the peculiarities of the disk
system, or, by its very nature, very close to "communicate" with
disk controller, and
at the same time using separate
routines that are located inside the ROM. Introduced us the 
inevitable changes in the codes TR-DOS, if possible not touched 
"bottom" level of the system and vital functions. But "there is 
no perfection in life, and that, alas, These changes will 
affect. 

   A few words on computer startup. If the submenu
"Disk Utility" item "Autostart"
is in state ON, then
every time the computer boots (after
"Cold" or "warm" reset) will occur automatically run the 
operating system stored on the device, specified in paragraph 
"from drive" the same submenu. Do not forget

to record the current state of the nonvolatile memory. For a 
system of TR-DOS, this means that an attempt will the program 
"boot ", if any program on a floppy disk or psevdodiskete 
present. In fact, as it is automatically pressing the ENTER key 
in menus 128 BASIC, and the system is transferred

command RUN "boot" for the device A, and RUN "x: boot" for the 
other (where x - drive letter). Thus, every time you 
automatically find yourself in a familiar environment for 
themselves. 

   Note: Not all file
shell ("butts") will be loaded automatically from the device, 
different from A. This applies to those of them who are 
supposed to, firstly, a fixed allocation of memory after the 
start (note the two extra characters in the command RUN

Device B. .. D). And, secondly, to those who do not check
the name of the drive of his boot;
Such programs try to load your files are always from a fixed 
disk drive (A). If you prefer, these feeders can be simply 
modify and make them loaded with autostart. A

developers of new programs
strongly recommend to take into account this circumstance.


    Work Hard Disk

           for IsDOS


   As for TR-DOS, to work with
hard drive from IsDOS little
differ from that of a floppy disk.
Although there are several specific points.


      Create Subkey


   You must first create one (or several) sub-type IsDOS. Select
click Create partition ... (Remember, this should be done in
submenu Local partition manager). Move the cursor to the line
labeled Unused, then press ENTER.

   The line appears
TR-DOS. SPACE key, select
Type IsDOS (types vary cyclically when pressing the key),
fix the choice of key
ENTER. Enter the name of the subkey
(Not more than six characters). Fix input the name of the key
Enter. And finally, set the volume
subsection, in kilobytes.

   Company Iskrasoft requires that the volume of the section 
did not exceed 16384 KB. In our view, the optimal value of 
8000-10000 KB. Remember the exact figure (because, 
unfortunately, at present time on subsequent viewings

volume partition table is displayed
in whole megabytes).

   Produced by manipulation
partitioning IsDOS written to the hard disk only when
exit from the submenu Local Partition manager (or when you 
explicitly select the item Write to disk). For confirm the 
changes in the table on you will be asked to give an 
affirmative answer (Press Y).



      Connect driver


   Note that the newly created
subsections do not contain any information and are not connected
to any devices in IsDOS.
The next phase - creating a logical structure on the hard disk. 
Communication between the system and hard disk driver developed 
by us provides mhdd.blk. 

   Load the OS from a floppy IsDOS
(For the hard disk drive can be used only option Classic). 
Download the driver mhdd.blk in memory - for this, place the 
cursor on the file name and then press ENTER. Make sure to load 
the driver can program dev.com, usually located in the 
directory \ UTIL - in the left panel should appear

mention of the driver (MHDD).
Placing the cursor on the line with
driver name (left panel), in the right panel of
You can select a device IsDOS,
to be connected to the hard drive (a "+" indicates the 
connection is changed status of the device key SPACE).


   Which device you choose? Shadow Monitor allows you to work 
simultaneously with four subdivisions of any system (as it is 
four devices can be connected to the menu screen of the 
shadow). The current version is observed, in addition, 
following an agreement - the device names and device names are 
TM, a driver mhdd.

blk, coincide. That is, the device A in the Shadow monitor 
complies with the A in IsDOS, unit B - B, etc. to the device D. 
Due to the fact that devices A and C are usually employed (The 
first under the drive, the second under electronic disk), are 
devices B and D (device B, occupied by the second disk drive

Driver sys_driv, available at
while the hard disk drive
disconnected from the driver -
in short, you can manually configure your system). After
the driver mhdd.blk loaded into memory and is connected to any 
device must be connected to the sub IsDOS hard disk device of 
the same name in the Shadow Monitor. 

   To do so, TM (by pressing the Magic), the menu
Hard disk utility, select
Mount the appropriate device, and then from the table of local 
partitions, select the desired section. Communication 
procedures devices and sub-section does not

differs from that of the ramdisk TR-DOS, except that it is 
enough simply to choose a subsection IsDOS. Return in the 
program - get out of TM. 

   Now, when communication is established, you can create the 
logical structure of the subsection. To do this, use the 
create.com, usually located in the directory

\ SERVICE. Set the device name associated with the hard disk, 
change the device settings: Sec Size (sector size) - 256; Dev 
Size (size of the device) - the amount of sub-section 
kilobytes, reduced by one and then multiplied by four. For 
example, if the amount of section 5000 KB, (5000-1) * 4 = 19996 
(Program "corrects" this value up to 19,992). After successful 
completion of the device can work with it, as with regular 
floppy disk. 

   On subsequent downloads IsDOS must repeat steps
connecting the driver (except, of course, invoke the program 
creat. com - because the structure is already created) or to 
modify the startup command file to automatically load the 
driver disk (the connection made in the Shadow Monitor, are 
saved automatically). Use the documentation firm Iskrasoft. 

   It should be noted that one can "simultaneously" to work 
with more than one device (and accordingly, subsection) to

Hard disk - connect to
driver mhdd multiple devices, and in the Shadow Monitor
associate with the same devices with several subsections
type IsDOS. Then, create a logical structure for each of the
them. Moreover, it is possible to one
and the same device IsDOS connected directly in the process of 
different topics. To do so, the Shadow Monitor and link to the 
device sub IsDOS, then return to the operating system IsDOS and 
reread directory device.



       Startup IsDOS


   The use of floppy disks to boot the system when there is a 
hard drive, a few tires and can cause confusion. We

offer to give up a boot diskette and use the mechanism of 
auto-TR-DOS programs. In a nutshell, the method

looks like this: you load the operating system as IsDOS
usually configure it to your
needs and then create a TM
image file of your computer's memory (he
created within the TRDOS), put the file on
hard drive, and tells the computer startup of this file. As a 
result, immediately after power is

"Automatic" startup IsDOS
(Actually, you just find yourself at the point from which you 
made an image file memory with all the settings and assignments 
in the system). Of course, this does not best, but so far the 
only possible solution to the problem. 

   Now about this in more detail. First, learn to work with 
hard disk drive, as shown in the previous

section. By the time the image file dump you already
should be able to work out with IsDOS
hard drive. Second, prepare a disk image of TR-DOS, where you 
will save a copy system. Next, do the following:


   Reset the computer;

   Load the operating system IsDOS floppy as usual;

   Load the memory of a computer hard disk drive mhdd.
blk.;

   Adjust the driver program
dev.com.;


   Now you can save a copy
memory. Note: in order
that at the next boot
buffer drivers hard disk
were clean before storing copies of memory do not select a 
panel file shells IsDOS device connected to

hard disk. It is best if you call the selection panel devices, 
move the cursor to the desired name, and at this point to save 
a copy of memory. Then in the future you will just have to 
press the key ENTER. 

   To create a dump
Use the menu Save 'Load
Shadow Monitor, details
Alternative Magic-files are described in the brochure AA 
Larchenko Short description of the functions Professional 
growth of informal service computer monitor "Scorpion ZS 256 
Turbo" ". Briefly, the situation is as follows

way: to save a copy
memory you need to select Save ... menu, Save 'Load of
program. Write to the disk begins immediately after the job in 
the service window that appears, name file. File name is given 
without quotes and specify the type, but

the general case must be preceded by
drive name (separated by a colon). For example, specifying the 
name isdosimg lead to the creation files (and they are likely 
to be several) of the current for the TM device (do you 
remember what device is the current? Can be found in TM, but why

complicate your life?) specifies the name
file in the form b: isdosimg, you explicitly specify on which 
device to create an image file memory. 

   Created on ramdisk file
dump with IsDOS, append
there is BASIC program loader, the program name should be
"Boot":

 10 CLEAR 28900
 1920 REM ---- Change file name
 30 LET n $ = "isdosimg"
 1940 REM
 1950 REM ---- Load program n $
 60 LET a = 29000
 70 LET c = 9: GO SUB 160
 80 FOR i = 1 TO LEN (n $)
 90 POKE a, CODE n $ (i)
100 LET a = a +1
110 NEXT i
120 LET c = 3: GO SUB 160
130 RANDOMIZE USR 29000
140 STOP
150 REM -------------------- 160 FOR i = 0 TO c
170 READ d
180 POKE a, d
190 LET a = a +1
200 NEXT i
210 RETURN
220 REM ---- Code
230 DATA 217,229,1,0,0,58,246,

    92,207,139,0,225,217,201


   In line 30, you can specify
another file name a full copy
memory.

   To activate auto-start to the submenu "Disk
Utility "item" Autostart "set in a state of ON, and in 
paragraph" from drive "to specify the device name associated 
with the ramdisk. Do not forget to write these changes in 
volatile memory. More complete information

on auto-mode is contained in
already mentioned earlier pamphlet
Short description of the functions of professional growth of 
informal service computer monitor Scorpion ZS 256 Turbo ".



         Work of other

      Operating Systems


   As already mentioned, for the OS, other than TR-DOS, 
requires a special driver, which will provide access core OC to 
the selected section hard drive. Currently, work on connecting 
the two systems: Micro DOS and IsDOS. Micro DOS (Port System

CP / M) - a full OS, which was originally focused on the hard 
disk drive, is needed primarily for expansion functioning of 
the Shadow Monitor. The system will completely transparent to 
the user - that is, if desired (Or reluctance), he did not

will know that such a system
installed on his computer.
The main objective of the project - Support for the programmer, 
we recall that most of the TM was written

programs that use
CP / M.

   Analysis of the functioning of Is-DOS has shown that it
design were taken into account (by
our opinion) not all the requirements for the system,
which must operate autonomously on the hard disk. This creates 
certain inconveniences, as For example, when working with the 
controller computer KAY - Loading system is a floppy disk,

and then loaded the driver
hard drive. Proposed by the above method of the system startup
can not be considered successful,
why work in this direction will certainly continue.


           *


      NEW SUB
SHADOW SERVICE MONITOR (RST 8)

   TO WORK WITH CONTROLLER

        PERIPHERALS SMUC


   A number of new challenges for the semiconductor 81h
R8DOS (call the built-in monitor disk interpreter
subfunction code specified in register C):


   Changed subfunction 9 (SETWRK)
Disk (R8DOS). Starting with version 3.0a (code 68
04/29/1995), in the registers DE and BC
return code version and date
compile the monitor (in previous versions of these registers 
are not changed). D - code version; C, B, E -, respectively, 
month and year.



   C = 34 ($ hddid) - Identification
hard drive.

   in: 512-byte buffer, a pointer to which is given in
workfl (subfunction 9).

   out: CY - error (no HDD)

   In principle, the identification of
happens automatically when
boot, this subfunction
determines whether the disc general
and attempts to return to clipboard
Sector-ID that was read
from the HDD.


   C = 35 ($ hddmount) - the connection section to the driver 
HD. Connects to the specified sub- hard disk drive, after

it becomes possible read / write operations of the section;
if you connect a disk image
(Ie given name of the subkey TRDOS and the drive name in it), 
it becomes possible treatment of TR-DOS.


   in: Akk - the type of operation is given by bits (in 
brackets [] are given priority - 0 highest). 

   7 [2] - Auto-ie
connect what is specified in the Gaza avtonastroek, with bits
0, 1 - the disk number (0 - "A", 1 -
"B", 2 - "C", 3 - "D"), disc A -
only when hardware support,
otherwise an error.

   6 [0] - disable subsection
from the driver (the prohibition of transactions
read / write), in this case
bits 0, 1 - the disk number (0 -
"A", 1 - "B", 2 - "C" or 3 -
"D").

   5 [1] - to connect the sub-
the driver, pointing out (in DE) address
descriptor (length of 25 bytes)
return for the previous
connections (see bit 4).

   4 [4] - to return to the memory (by
HL) descriptor is currently connected to the driver section;
Only this team can be made in conjunction with others.

   3 [3] - Connection by name
address of the name in memory in DE: text string of the form 
[dr:] [\] part \ dos, where part - the section name, dos

- The name of the disk under TR-DOS,
if not set dr, then the connection is specified by bits of 0 
and 1 disc. 

   2 - should be 0.

   0, 1 - number of drive: 0 -
"A", 1 - "B", 2 - "C", 3 - "D".

   out: CY - error (any error, including the "partition not 
found"). 


   C = 36 ($ hddrd) - a direct reading of the sub-sectors of 
the hard disk. 

   Reading is from the "current" sub-section - the last
sub connected subfunction $ hddmount.

   in: hl - the memory address to read, de - starting sector 
number (counting from 1!), b - number of sectors (the sector 
size 512 bytes!)


   out: CY - error.


   C = 37 ($ hddwr) - direct entry
sectors in sub-section hard
disc.

   Recording is done in the "current" sub-section - the last
Subpart connected subfunction $ hddmount.

   in: hl - the memory address where to write, de - initial
sector number (counting from 1!), b -
number of sectors (the sector size
512 bytes!)

   out: CY - error.


   C = 38 ($ hddpart) - return the table (directory) of 
subsection. Each entry in the table describes 16 bits, where 0 
- the type of sub-section, only the lower 5 bits (0 - No, 1 - 
TR-DOS, 2 - MicroDOS ...), +6 - the amount of sub-section 
sectors, 10 - the name of sub (6 bytes).


   Note: get the name of sub-TR-DOS can be plugged
Subpart TR-DOS (see the function
35, without specifying the drive!) And
hereinafter - direct reading sectors 0 and 1 - catalog discs.
Directory format is similar to the format of the table 
subsections. 

   in: Akk - should be 0, hl -
buffer address for the table (1024
bytes).

   out: CY - error.

   de - the number of involved
entries in the table.


   Function 89h (R8time), call
RST 8, allows you to install or
read the time from the chip
nonvolatile memory (CMOS),
operation code specified in register
D (individual bits):

   7: (1) - write the value
time and / or date (0) - read the values ​​of time and / or 
date. 

   6: (1) - read a buffer
(Only if bit 7 = 0) (see bits
5).

   5: (1) - direct reading (6
bytes of data from the CMOS), (0) - read format ASCII.

   0: (1) - work with a date (0)
- Work with the times.

   In addition, the call to register HL may indicate
buffer address (located in the 5
and 2 banks CPU), if bit 6 = 1.
Register E contains the format read: lower 5 bits - a symbol of
separator (for the output format ASCII); bits 7, 6 and 5, 
respectively, allow the withdrawal of hours, minutes and 
seconds, or for output Dates: 7 - display day of week,

6 - set to "0" before the number, 5
- Display month and before the word
year to add 19. The function returns the data or the buffer (in
as an ASCII string or a 6-byte: seconds, minutes, hours, day, 
month, year) or registers: C - seconds / date, B - minutes / 
month, E - hours / year, L - day of the week. In these 
registers are given values ​​to change the time or date. Bit CY 
indicates an error (chips CMOS not).



       Brief information

   to work with IBM peripherals


   The scheme of decryption controller
allows you to select any port
I / O peripheral
PCB IBM PC XT, connected to
SMUC.

   I / O ports IBM device are deciphered with 10 address lines 
(a9. .. a0). When this specification IBM, line a9 to "external" 
devices IBM PC XT should be able to log. 1, the hardware is 
provided in SMUC. The remaining 9 lines, but put them all in

address space of the ZX Spectrum is difficult - it is necessary 
to provide decoding and other devices of the controller. 
Therefore, two senior line (a8 and a7) are multiplexed, their 
status in the I / O operation is static. The value of these 
addresses should first be written in

special control register
controller. The address of this register in the space of TR-DOS 
ZX Spectrum - 0ffbah. Since the other bits control register is 
used for internal needs of the controller necessary to ensure 
their correct installation. 


   Quest bits a8 and a7:


        D7 0

        D6 1

        D5 1

        D4 1

        D3 0

        D2 A8

        D1 A7

        D0 1


   Attention! Controllers
SMUC versions 1.1 and below was a mistake, did not affect the 
performance of HDD. Rank A8 address bus slot handles IBM does 
not discharge D2, and discharge D3. If you have a controller 
versions 1.1 and below, you need to make their own its revision 
(correction of our error). To do this, cut the wire that goes 
concluded 1533TM9 6 chips, and Connect pin 6 TM9 concluded

9 sockets for i8259A with a short jumper. Except
it is desirable to change the firmware chip ALTERA
7032. Replacing the firmware version
produced at the company "Scorpion"
free.

   Another installation is in bits D7,
D6, D5, D4, D3 and D0, except as shown above, is unacceptable 
and may lead to an inoperable

controller.

   The remaining seven address lines
directly transferred to an IBM slot.
To select the IBM device is necessary to ensure full 
shestnadtsatiznachny port address O ZX Spectrum, which

should set the line selection
of the slot and addresses in it. Address to the address should 
be made in the address field of TR-DOS. 


       Selecting IBM slots:

 Scorpion IBM Scorpion IBM


   A15 A07 0 1

   A14 a4 A06 1

   A13 a3 A05 1

   A12 1 A04 a6

   A11 1 A03 a5

   A10 a2 A02 1

   A09 a1 A01 1

   A08 a0 A00 0


   AN symbols denote address lines I / O ports on the cards IBM 
PC XT. 

   Example card access serial COM1,
connected to the controller SMUC.
The base address of the device COM1,
specified in the IBM-compatible cards - 0x3f8h. First
determined by the contents of the control register (address 
lines a8 and a7). To address this 0x3f8h:

a8 = 1, a7 = 1, therefore, in control register must write 77h:


        D7 0

        D6 1

        D5 1

        D4 1

        D3 0

        D2 1

        D1 1

        D0 1


   Next, calculate the address of the external device in TRDOS; 
substituting in the table correspond to address lines, we 
78feh: 

 Scorpion IBM Scorpion IBM


   A15 A07 0 1

   A14 1 A06 1

   A13 1 A05 1

   A12 1 A04 1

   A11 1 A03 1

   A10 A02 0 1

   A09 A01 0 1

   A08 0 A00 0


   To access the I / O ports ZX Spectrum, addressable in the 
TR-DOS, in the Shadow Monitor, there are two routines that are 
located in the part TRDOS ROM: 


        org 3ff0h

        out (c), a

        ret

        org 3ff3h

        in a, (c)

        ret


  Sample code that reads bytes
from the data register COM1:


        ld a, 77h; bytes
to set bits A7 and A8
on IBM-slot.

        ld bc, 0ffbah

        call wrtrdos

        ld bc, 78feh

        call rdtrdos

        And the data in the accumulator

        ;....
wrtrdos:; entry port
I / O, located in the space
TRDOS.

        ld hl, 3ff0h

        push hl

        jp 3d2fh
rdtrdos:; read from
Port I / O located in the space TRDOS.

        ld hl, 3ff3h

        push hl

        jp 3d2fh



      Further development


   In the very near future we
plan, if possible, to introduce a more convenient way of working
SMUC controller in the system IS
DOS. Future plans
expanding the functions of the Shadow Service Monitor 
associated with supporting devices installed the controller 
SMUC. Here we is primarily to support

HAYEs-compatible modem, as well as how to connect the drive to
CD drives and CD ROM for Release
Spectruma. Besides, being
work on the Russification of the Shadow
Service Monitor. The emergence of high-speed external memory -
hard disk, and typing speed
data from the HDD is comparable to the rate of entry programs 
from ROM-drive allowed to start work on a hypertext help system 
on the functions of the Shadow Service Monitor 
Spectrumsovmestimym and computers in general. In addition, the 
planned establishment of operating an independent system 
psevdomnogozadachnosti that T-type MagOS, but the built-in 
"Heart" of the computer and therefore work much more correct to

Besides having a nearly
unlimited memory. More
that, in our view, the connection of the hard disk
solves the problem of increasing memory
computer to any reasonable size. Moreover, such an extension
costs to the user much
cheaper than using direct chip RAM.
In addition to this, unfortunately, there is virtually no
standards for memory expansion
More than 128 KB, and so this
Additional memory is hardly supported by software developers. 
The use of HDD in as the expanded memory

mandatory level support for the shadow Service Monitor will use 
the extended memory at least to

turn your PC into a multi-tasking system with both
running different programs, and programs will be absolutely 
standard, without any modifications, and the number of such 
programs is almost unlimited. In addition, the launch of 
several programs when the computer will not take additional 
time, such as in the current version MagOS. From the above we 
can conclude that the work on sovershestvovaniya software go 
constantly. As we have previously mentioned, it is the main 
difference between our computer from any other

Spectrum-compatible models -
constant increase of your computer only through the
software without
hardware changes. All
users Scorpion-compatible computers to announce the 
introduction of our new service: you can get from us a diskette 
with the latest firmware Profesional ROM and thereby obtain the 
latest version of system ROM. Also, you always can "download" 
Fresh from the flash PROM file-echo ZX Spectrum network FIDO.



           *
I / O, located in the space
TRDOS.

        ld hl, 3ff0h

        push hl

        jp 3d2fh
rdtrdos:; read from
Port I / O located in the space TRDOS.

        ld hl, 3ff3h

        push hl

        jp 3d2fh



      Further development


   In the very near future we
plan, if possible, to introduce a more convenient way of working
SMUC controller in the system IS
DOS. Future plans
expanding the functions of the Shadow Service Monitor 
associated with supporting devices installed the controller 
SMUC. Here we is primarily to support

HAYEs-compatible modem, as well as how to connect the drive to
CD drives and CD ROM for Release
Spectruma. Besides, being
work on the Russification of the Shadow
Service Monitor. The emergence of high-speed external memory -
hard disk, and typing speed
data from the HDD is comparable to the rate of entry programs 
from ROM-drive allowed to start work on a hypertext help system 
on the functions of the Shadow Service Monitor 
Spectrumsovmestimym and computers in general. In addition, the 
planned establishment of operating an independent system 
psevdomnogozadachnosti that T-type MagOS, but the built-in 
"Heart" of the computer and therefore works much more correct to

Besides having a nearly
unlimited memory. More
that, in our view, the connection of the hard disk
solves the problem of increasing memory
computer to any reasonable size. Moreover, such an extension
costs to the user much
cheaper than using direct chip RAM.
In addition to this, unfortunately, there is virtually no
standards for memory expansion
More than 128 KB, and so this
Additional memory is hardly supported by software developers. 
The use of HDD in as the expanded memory

mandatory level support for the shadow Service Monitor will use 
the extended memory at least to

turn your PC into a multi-tasking system with both
running different programs, and programs will be absolutely 
standard, without any modifications, and the number of such 
programs is almost unlimited. In addition, the launch of 
several programs when the computer will not take additional 
time, such as in the current version MagOS. From the above we 
can conclude that the work on sovershestvovaniya software go 
constantly. As we have previously mentioned, it is the main 
difference between our computer from any other

Spectrum-compatible models -
constant increase of your computer only through the
software without
hardware changes. All
users Scorpion-compatible computers to announce the 
introduction of our new service: you can get from us a diskette 
with the latest firmware Profesional ROM and thereby obtain the 
latest version of system ROM. Also, you always can "download" 
Fresh from the flash PROM file-echo ZX Spectrum network FIDO.



           *