Echo #06 30 июня 2000

Железо

Iron - Further development of the controller for the drive to connect 4 drives.

 Refinement of the controller

    drive for

     Connection

   4 drives.

Igor / ASt


  Hello to everyone who loves and respects a memorable 
ZX-Spectrum. Here and now I would like would tell you about one 
uncomplicated revision floppy drive controller. Currently,

Drives are no longer a luxury for $ 20 and
them without any problems can be purchased for a penny, or get 
for free unwanted pisishniku ​​five inch floppy drive to 1.2MB 
(most of which are easily reconfigured to work on the ZX), and 
if lucky, then fuck in the cheap trehdyuymovik. All

this I mean that it is now no problem
install on your Speccy up to 4 drives with minimal cost, the 
more TRDOS that supports it, and most system programs, too. 
That's actually we came to the topic of this article. 

  Most controllers TRDOS not support more than two drives. How 
does it define - yes very simply, in the system need to go to 
drive C: or D:, give some type of command RUN or

CAT. If you've done this with the drive C: and in this case 
drive A: not react to your actions, it means nothing to alter 
not be connected in parallel and need only a couple more of 
these devices on plume. Otherwise, have a little fiddle in the 
controller. 

  I'll talk about remaking the controller whose control 
register (port # FF) collected on the trigger TM8. To finalize 
the required two chips - one TM8 and ID14, or any other decoder 
with inverse output and increased load ability (open 
collector). Originally trigger TM8 included something like 
this: 


              TM8 VG93 LA13

                      (28) ______

            D T Q 'o Disk B

  D0 1 1 1 2 x

  D4 May 2 o 3 ______

  D2 on March 12 on July 2 'o Disk A

  D3 April 13 o 6
from deshif-3 10
operator 9 C o 11

                  April 1915

  5 In 1 oR o 14



  As can be seen from the scheme - the problem is,
that drives deciphered only one bit D0.

  The board should be cut back lanes
going to the loop of chips LA13 and identified above as Disk A 
and Disk B. Soldered on top of existing TM8 another the same

chip, connected in parallel with the output
1, 8, 9, 16 and tilting the rest. At 1
conclusion of a new trigger to start the signal D1,
which can take from 8 O VG93. Next
should be placed somewhere on the motherboard
K531ID14 decoder controller (preferably closer to the loop, so 
as not to enmesh controller card extra wires) and

unsolder it by following the above scheme,
while not forgetting to sue him food.


          TM8


     4 D T Q 2
D0 January 1

        2 o

        March 2

        4 o

      March 9 DI DC / DMX DO 4______

        C o 2 0 o Disk A

      1 4 1 5______

       oR o March 1 o Disk B

                       2 6______

      TM8 (new) 2 o Disk C

                    1 7______

      4 D T Q 2 o E 3 o Disk D
D1 1 January

        2 o

        February 3 _____

        4 o MOTOR

      September 3

        C o

      April 1

       oR o



  MOTOR signal must be taken with a trail going to the drive 
(16). New signals Disk A, Disk B, Disk C and Disk D is necessary

soldered to the wire output loop 10,
12, 14 and 6, respectively. That is, in principle,
and all dorobotka. Now you can use
in just four floppy disks without the constant peretyrkivaniya 
them. And yet - if at hand did not have the right decoder, and

really want to hurry up to enjoy working with 4 drives, you can 
use the chip ID4 and ID7 (as more common), but it will

output signals from these mikruh miss
through some logic locked with
open collector type LN3, LP12, and LI2
etc. If you use mikruhi with inversion
(Type LN3), the output signals are passed through two logic 
elements. 

                   -



          Connecting the printer.


  That's the "Computer News" has found the plate interface 
connector pinouts some printers. Maybe someone will useful.


Yahen P.


  Frequently asked question: "How can I connect one
a printer (usually from ancient)
to the computer without having documentation on it? ".


  Below is a table that indicates
location of a signal to block parallel printer.



                IED and C C C C C C E E

                BP 1 R M M M M M M S C

                M S 0 n 6 6 6 6 1 6 1 P

                    O 0 P 3 3 3 3 8 3 8

                D N - - 3 3 1 1 1 2 4

                B M M 7 7 2 3 0 9 0

                - A and

                2 M D R P M

                5 P B P P P

                    3 - C 1 -

                    6 3 5 3

                        7 - 0

                                3

                                2


   STROBE 1 1 1 24 1 1 1 23 6 B2 B12 1910

     D0 2 2 2 16 3 3 2 3 1 B5 B4 two

     D1 3 3 3 14 5 5 3 5 9 3 B6 B3

     D2 4 4 4 12 7 7 4 7 2 B7 B2 4

     D3 5 5 5 2 9 9 5 9 10 B8 B1 5

     D4 6 6 6 4 11 11 6 11 3 B9 B6 6

     D5 7 7 7 6 13 13 7 13 11 B10 B7 7

     D6 8 8 8 8 15 15 8 15 4 8 B11 B8

     D7 9 9 9 10 17 17 9 17 12 B12 B9 9

   ACKNLG 10 10 10 26 19 19 10 25 July B3 B14 1

    BUSY 11 11 11 28 21 21 11 21 14 B13 B5 1914

     PE 12 12 12 30 (23) 23 No No 15 No B15 1916

   SELECT 13 13 13 32 No No No No No No A10 1915

    AFXT 14 14 14 22 No No No 30 (20) no B11 1911

  {OSCXT} no 15 no no no no no no no

    GND 16 16 No No No No No No No A10 A11

                                                  -12
 CHASSI GND 17 17 No No No No No No No A13

     5V 18 18 no no no no no no no no

    GND 18 - 19 - 20 - 1 - 2 - 2 - 24 4 - 5, A1, A11

               25 30 31 47 24 24 25 Aug. 28, 3-5 -14

                          nech parity parity parity 13

    INIT 16 31 32 20 26 26 No 27 17 No B13 1912

   ERROR 15 32 33 32 (28) 28 No 19 19 A9 A15 1917

    GND 33 No No No No No No 18, C1-A1-18
                                               21 9,12 9 25

     NC no 34 no no no no no no no
 SELECT IN 17 36 37 18 No No No 29 (16) B4 B10 1915



                   -