ZX-News #23 04 марта 1997

Iron - Disk drive 3.5. From purchase to maintenance: the selection and installation, connection podmenitel drives, floppy disks choice, the advantages and disadvantages 3.5.

                  IRON



               (C) Yuri Buravtsov (OneSOFT)


              DRIVE 3,5 ":

          from purchase to repair.



            Instead of Preface


  This document is intended for those
who decided to connect a three-inch
drive his car. And they certainly are absolutely right: have 
long ceased to recruit PC Floppy Disk 5.25 ", because a 
three-inch drive yet more compact than its" older " brother, 
and "three-inch" floppy disk damage is much more complicated 
than flexible. These, too, preserved in its title 
"flexibility", while bend it even if brute force is very 
problematic. By the same on the smaller size is already 
possible to write two times more than the "traditional".

In Russia, 3,5 "not so long enjoyed preferential popular since 
a long time there was no specific reason for the mass" 
reorientation "to 5.25" to 3.5 ". Y We do any innovation is not 
perceived at all, and not always willingly (remember the fact 
that until now, instead Windows'95 many fans of retro-software 
products continue to recruit hard on their keyboards with the 
birth of the PC well-turned phrase "Nc \ nc <enter>"). And if 
you've seen before IBM PC with a set of 5,25 "1,2 M; 5,25" 
360/720 Kb and 3,5 "1,44 M, then these machines are, apparently,

collected domestic companies, dealers known corporations 
meeting the requirements Users of the Russian and world 
standards. But the market dictates its laws, and Now you will 
not find software on anything other than a floppy 3.5.



  Responding to global requirements, known
sinkleristov circles of Petersburg firm
Scorpion also focused more on
3,5 ", true, but rather under the influence of savings on the 
power supply and space in Mini-Tower'e, but the fact remains: 
for Speccy appears a new standard in the Russian market. In 
this connection there question: if I could with their modest

(Rich, no one - delete as applicable)
knowledge itself to connect a second (third,
fourth, ... ) Drive if it is - a three-inch? The answer is: it 
is possible. If you can buy expensive things, holding a 
soldering iron and not afraid to burn your previously available 
drive, then this article can provide you with substantial 
assistance. Maybe not everything will be set out, although I 
try to explain all the problems and the openness with which I 
have ever encountered. Experience I have a not too rich, but 
because a radio-education venture

assert some aspects, set out in
this article.


            Choosing and Installing


  Drive I bought in July, one thousand nine hundred ninety-six. 
Obbegat all firms - wherever is cheaper (not out of greed, but 
from the thrift, which subsequently helped). Cheaper only in 
the market Avtovo, but they can sell not just a good thing. But 
a reliable indicator of a trehdyuymovok somewhat lower than 
that pyatidyuymovok. I bought a Mitsumi drive on

Countryside. They sell PC Hardware
(Later proved to be the cheapest - not
therein). While plowing the drive, there were no problems, but 
it is now in its ninth month. However, there are drives that 
spoil the floppy. Not information such as a floppy disk. In 
this case, with a floppy disk, you can work as a valuable, but 
it has to lose, so to speak, "marketable." It is a tin cover 
(see Figure 1) that some drives manage to evert, 


      3,5 "floppy

                          then remains
                    \ It is only
/ \ \ Tear and vyki
                      \ Nut. I hope

                         that your drive

   February 1 will not require
 \ \ You just for the sake of
                         locally Days
                         ting. But here you are,

                         Finally, acquires
                         religious drive.

                         Legitimate question:

                         where to? First

                         of pitch

                         inside

                         (Or outside ...)

                         rack. One

                         resistant, for example,
     April 3 measures can explosion
   / \ Lyatsya one

                         Rack your fifth
                         tidyuymovogo Thesis
                          kovoda. Mounted

         Fig.1 drive to stop
                          kam six M3 screws through the simple 
goals. Just before you install, look for a jumper

drive: they must be installed in
according to the selected mode of operation.
May, however, appear that any jumpers on the drive there (like 
me). Here enters into force the following statement: this drive 
will be on the Spectrum as a "B", and the PC - as "A". This 
they feature ... 


               Connection


  But here you have installed the drive on the racks
and now it must be connected. First connect the "nutritious" 
wire. Drive uses only 5 volts, so that Energy saving is 
obvious. The power connector can be asked in the market. Used 
the four "mother", pinout shown in Figure 2. Shield wire is not 
required. 


          BOTTOM PLATE DRIVE

                                                    top



                                                     bottom

     33 ................. 1 .... - Food

     34 ................. 2

                                       general

           data 34 pin +5 V


                                 odd number - total

                                 even number


                            Figure 2


  We now proceed to the terminal data. Used 34-pin female (on 
the drive - "Dad"). The market is full of such. Buy the best 
connections with two zamkamisamye reliable from all I know. Now 
pinout conclusions. According to the standard signals of all 
the findings in full compliance signals are "pyatidyuymovok," 
but because Connector "bumps" in your diskovodnuyu cable feed 
(loop) is similar as in connected "pyatidyuymovki. I urge you to

the utmost caution: confusing the first
Pin and tape, you can not
secondary "embed" connector at the same place, and
tape, not all can boast of its
long. "Embedding" should be very careful, pressing the cable 
conductor first castle. It is desirable to use small tisochki,

extending the width of the sponge to plug what some planks. If 
the grip you have not found, try to put a lock can be more 
evenly distributed, because if you lower edge of the castle is 
too low, and the middle but will be considerably elevated, the 
just in the middle of the castle and can break. Can he break 
down and in one of the eyelets. Once you've done this, you can 
turn off one side of the tape over the lock, and all this lay 
the second lock. This second lock "keeps" the first

since he could easily come off the connector without the safety 
net the second. 


  Connect the connectors to the drive for
power is off. Sequence
Connection terminals plays no role. Remove the resistor matrix 
with its five inch floppy disk (the matrix is

below, near the place where the dress connector, and looks like 
a chip; Of course, she is inserted in the socket). Now turn on 
the machine. 


  If the LED treatment of burns and does not go off, even if it 
- a floppy disk, then something You nahimichili ...



  If you do nothing - no emotion
handling or reset (to Scorpion'ah)
then check which way you connect to a tape drive or track 
circuit supply.



  If you could do it right the first time - it remains only to 
congratulate ... ;) 


         "Podmenitel" drives


  I want to say that if you
3,5 "connected as" B ", and you want to run with him the 
program, you will undoubtedly encounter some difficulties on 
the following: a TR-DOSe required to give the command: * "B" 
<enter>, RUN <enter>. It takes time, and sometimes because 
every second counts registered ... In addition, not all programs

running from the disc "B", continue with it
work. Yes another Scorpion'e if you
go into DOS with a blank drive "A", then
meet with great braking system. So I made myself some things,
which may swap drives "A"
and "B". Schematic and wiring electrical circuits are shown in 
Figure 3. As the switch is used beloved Dip type OSMT3 
two-piece for two positions. 


         "PODMENITEL" floppy drive


    The schematic circuit diagram


board to toggle / fee after

                    / Tumbler
drive "A" /


                                 to the pin. 12

                     / Data

                    /
drive "B" / a pin. 10

                                 Data



      Electrical circuit assembly



drive "A" \ / to the pin. 10

                         \
drive "B" / \ to the pin. 12

                  1 2 3



                  Fig.3


  Of the schemes you might guess that
the controller board connector must be cut before the two 
signals - "the choice of drive "A" and "drive select" B ", and 
in the resulting gap solder wire MGTF-0, 3 (Or, indeed, any 
other, though coaxial) switch, all of the body of the car. 
Initial conclusions toggle vpaivaivayutsya before the break, 
and the third - after the break front jack. To toggle crosswise

should be propayany second and third conclusions, as shown in 
wiring diagram. All conclusions should be isolated from each

other. Add more owners Scorpion'ov,
that they can use on the assembly field (if it does not employ 
this time) such kontaktiki that are used in PC board for 
interfacing with external cables. If the length of the wires to 
the switch exceeded one hundred millimeters, it must be on the 
external screen the noise. 


               Selecting disks


  Now back to Figure 1 to understand the device and the floppy 
drive principle of information processing. Standard on Floppy 
3,5 "provides a tin cover item 1, which protects the window

data disk from dust and mechanical particles that can damage
magnetic layer disc. The cover should easily move over to the 
left and resilience to distance not less than ten millimeters 
from the original position, as well as with just as easily fall 
back to the right in original state by the spring.

Insert the diskette in the drive should be just ahead of the 
lid, while on the body on the left should be depicted relief 
"Arrow" (position 2). By the way, otherwise you will not be 
able to insert it, no matter how cool ... But experiment is not 
worth it. Kinematics drive is set up so that when the disk is 
in drive, the cover is removed at a certain distance, and then 
as a floppy disk to "falls" down drive. Everything! Forget 
about your favorite castle Your faithful pyatidyuymovki (of 
course, for trehdyuymovki). Now, to get back to a floppy disk, 
simply click on this rectangular button at the bottom right (if,

Of course, you've installed the drive, so that
LED located on the bottom left). Do not forget to draw back the 
hand of time: you can get seriously injured wrist wildly sprung 
disk (I'm suddenly thought: why am I writing all this, because 
times have you wanted to 3,5 ", you probably know how to use it 
yourself lead. Although ...:).



  A few words about indexing the beginning
disc. On a floppy disk you will not find any
index holes. Only turning the disk upside down, you'll notice 
that in Slave of the disc except Center hole there is another. 
And that's what it is: when you insert a floppy in the drive 
and if the the power is on, the servo drive makes a few turns 
to find himself leading this pin holes. Status pin on the 
engine in strict conformity with the presence of the switch 
capacitance sensor under the engine. Such is the indexing of ...



  Now let's talk about the windows (not on Windows'
95:).


  Write protect window (position 3). Unlike
5.25 "defense record is not defined
your wealth in the region "serebryashek.
Protection of records can be easily installed
at any time, except, of course, that
moment when the diskette in the drive. Similarly, with the same 
ease protection can be removed. This is done a little

slider in the window, which is installed
two fixed positions:


        Write Enable / Write Protect

                   or

    Write position / Protected position,


       which respectively mean:


    entry is permitted / prohibited entry.


  So what's the problem with writing permitted
more civilized than the "five inch
my sister. "Though not devoid of such a system and a lack of: 
recording is prohibited, unless transparent window, and vice 
versa, if not transparent. Right kind of American system. I did 
some time to confuse these safe mode, from which washed three 
diskettes 3.5 "and one 5.25". In fact, just remember: on the 
labels to floppy disks is Such phrases, which I described above.

Label, by the way, too, are glued to the magic: the part below 
(where the word), and the rest - from the top.



  On a floppy disk 3.5 "can be written as 800 kilobytes of bare 
byte (iS-DOS), and 1.44 megabytes (the rest for PC). But you 
Speccy Oblomov 2HD. Not with a diskette, nothing to do with the 
drive, nothing to do with DOS. What where? KR1818VG93 
controller. He can not wind on one track with more than six

half of kilobytes. I tried to write a driver in the iS-DOS'ke, 
but only time spent in vain. And what is achieved in MS-DOS, 
this is the most 2HD? Yes, just only half compressed data 
density per track: instead of nine sectors of 512 kilobytes 
written eighteen. And so on Speccy window

pos.4 should always be kept closed.
Write a record, but did not find. So
that did not take the opportunity 1.44
succeed. Close the window can be any solid object, the 
transparency does not matter: the mechanical sensors. Can 
window just stick up "serebryashkoy, and can

before installing the drive solder contact sensors, or solder, 
and something lock them in a closed state.

I will say that the PC system understands any type of writing: 
that 2HD, that 2DD - without difference (the difference is in 
the tank). But the format drives for MS-DOS is best to Speccy.



  Now let's talk about the sorts of floppy disks. Best in the 
world, in my opinion, the 3M (USA). Currently, though I rarely 
buy them, but a friend's birthday - a great gift. Verbatim with 
Teflon coating, I do not take it, because I do not work in 
hostile chemical environments, and Teflon can just make notes 
directly on the disc with a ballpoint pen. And after such an 
ordeal disk continues to properly serve its lean to the owner. 
BASF, TDK - better buy audio tapes of the same name. But on

World markets extend domestic floppy - RAD. I do not understand 
this abbreviation, but I liked them because of price and

quality (I've got a few discs
iS-DOS - until cool, and "no new
hole! ":). Make them in St. Petersburg from the Japanese
and American components. Nowhere, except
how to market, I have not seen them, and this means that disk 
are only for export. In the market for a year now hangs a 
signboard, which is the sale of these disks with huge 
discounts. Just recently (today) bought two more packs ... 
Maxell - it's the batteries are ... MMC - cheaper than all at 
light, so - bad. NoName - never hold. They are even cheaper 
than MMC, but they can be written once in a lifetime.

The second will not. Yet there are floppy disks, have
which simply does not exist window
position 4. These diskettes initially wondered how 2DD, and 
such a floppy disk used on your drive with other drives may be 
incompatible, so choose the type of floppy disk, regardless on 
the density of records in accordance with the drive. 


      Advantages and disadvantages of 3,5 "


  Let's start with the disadvantages. On the copyright 
turbozagruzchikah immediately affects some lateness tone after 
step block of magnetic heads. Simply put, there are no 
differences between retrievals BASIC-large file with DOS and 
games "UFO-2" package "ZxWord-128" - speed

download the same. Several noisy moving block of magnetic heads 
(at least for me). However, this does not

detract from the merits of the drive:


  absolutely not audible, as it rotates
disk, and rotates if he did. Error
reader / writer can wait for years, intensive chasing head on 
the tracks. No problems with the clamp (oh, where is it on

MS5313 !..). Floppy disk can now be run in a mate, while fellow 
ohnet and floppy disk - not:).



  But what do you do if suddenly, after some time, a working 
manual drive suddenly refused to work? This means that it is 
time to repair, but that's a topic for another article ...



        __________________________