City #09

Iron - IBM-circuit analog-native serial port COM1 (COM2).

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                 PLANET SHELEZYAKA
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(C) V. Kazakov


  This information will be useful to those who would like to 
collect VCOM, but does not do so due to lack of chips and 
K170UP2 K170AP2. 

  I recall that VCOM - is the development of Kharkov
sinklerista VICa published in the ZX-POWER # 2, and
representing a IBM-analog-native serial port COM1 (COM2). I 
also want to say that all issues regarding the development 
itself and its software, please ask by telephone (0572) 
10-50-26. Victor asked. I just I want to help in replacing the 
deficient elements of the scheme on more common. And nothing 
more. 

  So, for the replacement of these chips, we need 3 pieces 
KT315, KT361 3 pieces, 6 resistors 1910 ohm, 3 ohm resistor 
680, 3 51 Ohm resistor, 3 1 k resistor and 3 diode KD504A. 

  All these elements are established in the scheme VCOMa
according to the figure below:



                                             TXD


                          ° ° -5 In


                    680 680 680


                  °

           10k ° RTS
23n VV51 ° DTR

           10k b to b to b to
19n VV51 _ | / __ | / ___|/ KT361

           10k | e | e | e
24H VV51


              51 51 51

                  ° ° ° +5 B


              1k 1k 1k PG

 3N VV51 ° ° SG
VV51 ° 17N
VV51 ° 22N

                 to b to b to b

           KT315 | __ | __ | __ 10k

                 e / | e / | e / | ° RXD

                              ° DCD

                      ° CTS

                                         10k


                |> | |> | |> |

                        KD504A


  Here vobschem is the whole shemka. She was taken from the can 
not remember already a number of magazine radio, where 
considered serial interface, if I remember correctly, the 
computer RADIO-86. 

  The only unresolved issue for me in this
(And vobschem something in the original) scheme is the signal
DCD, then there really is DCD, or is it a DSR,
that I think more veroyatno.Vprochem, this is the question
to the author of the scheme.

  I did this to forgive. Till we meet again.