History - Spectrum clones: Lviv version and Leningrad.

                                 
                                        
 Lviv version           
 -------------------          
                                        
 This variety may include
cens Spectrums with a separate memory field -
tee.                                     
Actually "Lviv" if there is a ready-
The memory expansion board is being redesigned
It’s in 128k, it’s elementary.                 
                                        
 "NIRTI version" was produced in
Lvov Research Institute
Diotechnical Institute and Lviv
Electron software.                          
Completely repeated the modelE. Natopta and
Yu. Dobusha.  The only difference was
that it was implemented onPLANAR m/c
(needbelieve, based on what is available in
that time is at the disposal of the producers
components).                         
                                        
 "Delta-S" according to the circuit design
repeats the design of the processor part
"Lviv". At the same time, the blocking
the condensers are located in it extremely
successful, but the power buses are unacceptable
cues. Therefore, here when connecting the board
expansion requires additional software
connecting blocking capacitors to
EACH memory m/s.                      
                                        
 The next two models deviated from the "proto-
parent"6 a little further.            
                                        
 "Orizon-micro".  Produced by the plant
radio devices in Smela, Cherkasy region
tee.    The processor part repeats
"Lviv",but implemented SEPARATE control
influence of the lower memory and braking circuit
nia.  Therefore, of all modifications "Lvo-
va"  this is the most difficult to transfer
deal.                                  
 Joystick selection failed:
ee has to be turned off as when attaching
when the drive controller fails, and when
memory expansion up to 128k.              
 All output signals are sampled
us: there are APBs on the address and data buses.
It would seem like a sensible decision. BUT! Communication
with the controller is INTERNAL connection.
So the APb is being created here not only
the required increased consumption, but also -
it happens that it is also unacceptable - temporary
delay. And these APBs are placed in an extremely un-
successful: 4 pieces nearby, without a single block-
transfer capacitor, next to the pro-
tsessor (!).                           
 It is not surprising that the controller,
connected to such a computer, at first
doesn't work - and starts working after
installations next to one of the APb of one-
the only blocking condenser
ra.                                     
                                        
 "Byte".  Production - Brest Production Association
computer facilities. Functional
nal nodes are implemented on the RT c heap
RADIATORS (?), there is an HF modulator
(for antenna input) and RGB encoder (need
supposed to work in PAL).            
 After connecting the controller, the system
categorically does not want to enterTR-
DOS.  It is possible to achieve normal operation
by replacing the existing non-standard
new ROM to standard.                
                                        
 Leningrad version          
 -----------------------         
                                        
 This variety includes Spectrum
rooms with common, and not separate, as in
"Lvov", memory field, which is fundamentally
has a scheme for expanding them to 128k.       
                                        
 Models "Leningrad-1"  and "Leningrad-2"
(development by Zonov) have one interest -
newfeature: when trying to RECORD
processor of the program in ROM (erroneous, ec-
Naturally) the byte ends up in RAM - in the post-
the last quarter of the address space
processor.  However, such is the confusion
when selecting ports, generally "Laziness" is inherent
ngrady"- due to their very “economical”
diode decoding.                     
                                        
 Vinnitsa version. Almost a copy
"Leningrad", but made more accurate
decryption of joystick and keyboard ports -
ry.  There are quite a lot of blocking capacitors
enough, but they are not spaced enough
competently.                               
                                        
 DIK (Children's gaming computer, New
city) in its processor part is fully
completely repeats"Leningrad-2".         
                                        
 And now - more complex varieties
ty:                                     
                                        
 Mico-Best. Manufactured by Mico,
Lviv. It was created under intensive co-
inputs from OKB developers
Lviv Polytechnic. About this computer
a lot has been written in "Optocoupler" (NN7, 8, 21,
27).                                    
 In terms of its execution, this model is strong
but different from all the others - in all
relationships. In particular, the keyboard: there
There are not normal keys, but rather
buttons (for the sake of “saving”, or what?). So-
With our buttons you can only set modes
Well, nothing more.  But dial them
text?!                                 
 Comes with an additional block,
containing power supply for the computer and disco
water Not the most successful design re-
Solution: the power supply and disk drive must
be performed separately. And according to its con-
The structure of this “joint block” looks like
very unsightly - like some kind of self-propelled gun. 
   The computer has the following basic
feature.  When turned on (or "reset"
ce") all 16k ROMs are reloaded into free
a certain part of RAM using a program that
written in RF2. As a result of this it seems
it would turn out that the ENTIRE memory field (and
RAM, and pseudo-ROM) becomes, as it were,"general". But WHY are there such difficulties?!     
 After all, you can do it much simpler: remove
army RF2 and add LL1.                
 The most interesting thing is that after this
grove alteration "Mico-Best" transforming
is in Zonovsky"Leningrad". Well,
Is this a coincidence?
or serves as an indication of which of the
of these computers is original,
and which one is torn, judge for yourself.     
                                        
 "Robik".     Production - Cherkasy.
Has an original memory organization:
it contains one PYS memory line, and
one RUB. It would seem like a separate field.
But no!  In RUb the screen area is located
Yes, and the ee processor CANNOT READ
(and therefore test that
not eating healthy). Therefore she duplicates-
in memory on PYS. Thereby making
They ensured that the Z80 did not slow down
video processor. As in the case of Mico-
Best, a legitimate question arises: WHY
such difficulties?!  After all, information for
output to the monitor screen is read from
screen area ONLYvideo processor!
   In addition, all management is implemented
but not on discrete logic, but on PLM
556PT2.                                 
 All this does is expand the memory of this
the model is highly problematic.           
 There are other oddities there. For example
measures, "uhbepchoctb" signals R, G, B "re-
is controlled by a resistor. There is some under-
trim resistor between ground and
"+5B", and its engine goes to the inputs
K5SSLPS.                                
 And there are also signals ROMCS1 and ROM-
CS2, which disable, respectively,
zero and first ROM. I wonder who
it may be necessary to turn them off
separately?                            
 In general, a mysterious computer.       
                                        
 "Pentagon". This computer, exactly like that
the same as "Robik", contains two rulers
memory, i.e. hardware - separate or-
organization of memory, and programmatically - general.
In the same way, the Z80 did not slow down in it
deoprocessor, although this has been achieved
otherwise, notin a less crooked way.           
If in all normal Spectrums
for compatibility with standard TV size
the number of lines is
Z=312, which provides the frame rate
F=5OHz.  This achieves good agreement
pushing with the maximum permissible frequency
that Z80 3.SMHz, and frame interrupts
it is not slowed down.  Another thing is that when
launching "Pentagon" programs on
On other Spectrums they sometimes slow down
twice as much. To avoid this,
you have to make a line counter "nehtaroho-
similar."  This is done, however,
It’s quite simple: if in "Leningrad", for example
measures, row counting is implemented as      
                                        
 Z=312=16*12+16*7+8          
                                        
using feedback and decoding
states, then in "Pentagon"             
                                        
 Z=320=256+64=16*10*2          
                                        
and the decoding scheme is here in generalno need-
on.                                     
 It should be noted, however, that such
here  F=48.8Hz degrades ergonomics Spectrum
room,which, admittedly, is not
so cool.  After all, it is generally accepted that mini-
minimally permissible from the point of view of ergonomic
miki computer frame rate
tera must correspond to non-European
for whom the TV standard is F=5OGz even, but for Americans
kahckomy, with it F=bOGz.                 
 In general, the scheme "Pentagon" is built
quite soundly, without petty
savings on equipment inherent in "Le-
ningrad".  We can consider that as a basis
here is taken "Lvov version", but with
taking into account the developments of the "Leningrad variant"
ta".  So "Pentagon" really
mic computer frame rate
tera must correspond to non-European
to whom TV standard F=5OGz even, and American
kahckomy, with it F=bOGz.                 
 In general, the scheme "Pentagon" is built
quite soundly, without petty
savings on equipment inherent in "Le-
ningrad".  We can consider that as a basis
here is taken "Lvov version", but with
taking into account the developments of the "Leningrad variant"
ta".  So "Pentagon" really
can be called a certain "third variety-
ness".                                
                                        
 So, it is quite obvious that EVERYTHING is created
The bodies of the clones Spectrum came from "Lvo-
version"  - closest to
"branded Sinclair Spectrum",introducing
it has all kinds of circuitry and design
structural changes, each in moderation
of your understanding.