ZX Pilot #31 20 февраля 1999

Железо

about different - Noise reduction drive.

              O R W A N O M



(C) WWSoft



      On a "council" of the ZX-Revue.


   In room electronic journal, on a disk
"ZX-98/11-12 Review, published a short
Note, "Noise reduction FDD".

   Very sensible rational proposal
to reduce the noise by lubricating the drive
mechanism jettisons an extremely dangerous
present there recommendation disassembly
mechanism.

   What do you mean! Crazy? Parse precision mechanism for 
lubricant? "Well, muzhuki, you give! "


   Do you have equipment for alignment
in the assembly? This is the least - an oscilloscope and
spetsdisk with spetsdorozhkoy. And still did not prevent
would experience in such work - if not to learn from
own unit equipment.

   Apparently, the "advisers" have it all. A
on the other - not thinking? However, "and the old woman is 
proruha. Last advice to this theme directly gem: invited to 
lubricate ... disassemble the engine. And lubricate the 
bearings and ... "Teeth of the rotor-stator. Game! First, 
neither the motor does not designed for disassembly by the user!

So for the sake of lubrication something - exactly! All of them 
have specified in the documentation exterior point

lubrication. Secondly, the "teeth" of the rotor does not 
require lubrication, since the engine of any type No other 
mechanical contact force, except for two (and only two) 
bearings rolling or sliding.


   For the sake of relative overdue and
emergency surgery,
because you never take up the case "
themselves. It is clear that in addition to tools and 
environment (operating room), we need above all - the knowledge 
and experience. So? Well, your "five inch" MC53XX little 
cousin. Why should we think it so? ..


   Sane grain in the paper is. And try it "vyluschit. First. 
Lubricants require any mechanism. Therefore, it is necessary to 
periodically lubricate the drive as a printer, as well as all 
household equipment: tape recorder, player and so on. 

   Yes, indeed, lubrication dramatically reduces
noise floppy disk drive. But the Khoi-what "equipment" all
are wanted. Head, for instance.

   Usually in the accompanying documentation
is a drawing of lubrication points kinematics
"Lubrication chart. All lubrication points are accessible
a grease gun without disassembling the mechanism, or
minor not significant disassembly,
type of lift enclosure, enclosure.

   Here, in "53XX", initially with no problems
lubricates the runners carriage. But not the runners: a drop of 
oil drop to three points of reference carriage. One point - the 
far from shagovika runner, two points - on neighbor. At this 
near-direct contact with the edge of skid plastic cradle. Under 
them - for the drop. Excess oil off the edge of newsprint.


   Around the stepper motor actuator, with the back of it 
(engine) side of drive enclosure has a window. Just for

lubrication of bearings! By the front bearing
get close more complicated. It is necessary to do so.
A long needle to rest there in the shaft close to the
motor housing. Now hang on a needle drop of oil, and it will 
flow down the shaft. First estimate and find the angles

needles, and FDD. So that the oil spread out
the shaft toward the front bearing
engine. Excess oil, trapped in the motor housing removed. With 
the needle as it is convenient and the previous one operation 
on the carriage. 

   Apparently not prevent grease and steel
bidirectional transmission of the spring. As was
recommended in the article. But, again,
strictly: no rasfiksiruya anchor
Screw it.

   And, of course, as was said there, the oil must be a machine 
for, say, sewing machines, not avtol and butter with

plant.

   Although it is often dealt with specific brands of oils. But 
it is clear that, for the simple "Burghers" and "Esquire" these 
instructions difficult. Nevertheless, we must take care avoid 
even blunders. 

   (- ... That's gruel old men fry. -
Ostap sniffed - This is what, in the engine oil? However, okay, 
I'm not concerns. -)


   It is! It was in a car! For all
MC'ov and others. "Clover!"


   On this occasion, here are a few
concerns about the "beta-CD" interface.

   Schematics here contain a number of "snags" incorrect 
decisions. Of the latter We note that the diodes with a digital 
technique for perform logical functions (the "OR")

do not apply. It would be okay.

   But here is a diode between one of the outputs TM9
and access to the floppy disk "entry" - a
major "snag." As the logic of interaction and for the open 
collector of FDD, and standard push-pull "of TM9.

That - empowering, but it - "liquid" series
K555 or even 1533. About the logic
here. With this even worse. Long to explain.
I recommend: Get rid of the diode, the abandonment of
"Break the chain" (instead of the diode). The system remains 
operational! So leave! (But I must warn: in mathematics

TR-DOS does not understand.)

   With two drives is useful to make
the next revision. In connection cable, in principle, are not 
necessarily wire IAC - motor turn. " Signal IAC

You can remove the right to respond drive connectors, connect 
pin IAC chain selection floppy DS0 on a single connector, and 
MVK with DS1 - on the other. In this case, the main drive

included in only one drive in
one that is selected. Otherwise, if the original
scheme, with the work of any of the drives,
spinning both the main drive.

   Additional savings in a single wire in
cable at the same time, this is as it should have
"Good watchmakers," - "unnecessary details when
assembly!

   Must also be noted, especially for
Owners dvuhdiskovodnyh systems following. Output line with the 
interface side of the "floppy" is very much loaded, and

with two "H" may be overloaded. Even
if the second drive - a three-inch. " On
"MC53XX" in the direction of line with respect to
"+5 V" look resistors 330 ohm. They give
load on the lines of 15 mA. This is the maximum
permissible for a series of K155. Because would not hurt to 
replace the output BETA 155LN2 to a more powerful 155LN3. While 
the documentation for the list to the scheme here means 555LN2 
that all wrong, and what many are already aware of. But as it 
turns out even 155LN2 is not at all "to the court."


   Anyway, with two five inch
drives, remove one drive
(Any) resistive assembly that is inserted
them in shestnadtsatikontaktnuyu chip-socket - another line is
overloaded. It was supposed to do when
"Daisy", a group of connected
Floppy disk drive. In "three-inch" system to another, their
in modern complex is not expected
more than one. (Second-HDD hard drive.)
Because "treshki" overload the line, if two or more. But if you 
have "3" + "5", then "5" Resistor clear:

required load line provided from the "3".

   Success enthusiasts "Spectrum" in our
confrontation "pisyukam" and, allegedly, a new
another "Amigo." Old Friends are Best
two! Yes? Amen!