Optron #08 27 февраля 1998

Железо

Mike Best - Part 2: Circuit diagram, memory 256K. Problems Kempston Mouse.

           Miko-Best (Part II)



(C) Hacker Rasp, 1998a namely,
free computer Miko-Best.

  To begin with I want to tell a little that
I think about this comp as a "user" (although it is not). For 
Users Laptop is very convenient - small size

(The entire board is placed in the keyboard itself
computer), the presence of RGB and video outputs,
access to power, and most importantly,
so is the existence on the territory of Lviv
"Service Station" Miko'v. But there is
and shortcomings, do not give to live in peace
a simple "nick" - printer interface for
AY-8910, which does not work, and
also "skoroportyashayasya" and not entirely comfortable Claudia.

  Inside the complex looks like a very peculiar way, too - one 
line RU7-X (256K), VV55, rush signals for the address 
multiplexer, a little logic, two RT-shki, and most importantly 
- IC imennuemaya ULA, which misleads many users,

believe that this proprietary ULA. But this
not so.

  Another is to touch the paper-based support
computer. To a computer is very good
User Manual, with description of all razyemov and
buttons, there b another little description of Z80,
VG93 and AY'ka - the price he had been were not. Schematic 
diagram daubed with tears, sometimes it is necessary for half 
an hour to look for "signal X, ushedschy 8 th leg to nowhere." 
A wiring diagram in the sales package does not smell (well, 
it's fixable;)). 

  In general, the complex is almost good to
the moment when the user wants to
expand its configuration - add
mouse, modem, Sound Drive, etc., and it
is impossible because of one or two
technical failures. The purpose of this article and
was the removal of certain "zhelezyachnyh"
computer problems.



             Wiring diagram



  To get started give wiring diagram of
companies, because the computer is not attached, and to 
understand how something should be. Proportions due to the 
electronic submission were lost, but the location on the chip

100% of the original.



  ■ D17 D18 ■ D19 ■

                                ■

                    D24 ■ D

              D12 ■ 2

  ■ 3

        ■



  D21 D22 ■

                             D53



                    ■

                  D26

                             ■
 D31 ■ D

                             2

                             7
 D32 ■


 D33 ■ ■

                             D

                             2
 D34 ■ 5 ■

                                D

       ■ 4 ■
 D35 ■ ■ ■ ■ ■ ■ ■ 7 D

       D D D D D 4

       2 5 4 5 3 9
 D36 ■ 9 0 1 1 9 ■

                                D

                      D43 D54 4
 D37 ■ ■ ■ ■ ■ ■ 6 ■ D

       D D D D D D 5

       3 1 5 4 4 4 5
 D38 ■ 0 6 2 2 0 4 ■ ■

                                D

                                4

    ■ ■ ■ ■ ■ ■ ■ 8

    D D D D D D D

    8 1 5 6 2 1 2

       3 0 1 8



       ■ ■ ■ ■ ■

       D D D D D

       1 7 1 1 4

       0 4 5 5



       ■ ■ ■ ■ ■

       D D D D D

       1 4 3 9 February Modulator



 D1 - 555LN1 D20 - 561LN2 D44 - 561LE5
 D2 - 555TM2 D21 - D45 - 556RT11
 D3 - 555IE10 KR1858VM1 D46 - 555LI1
 D4 - 555LP5 D22 - 27512 D47 - 555LA3
 D5 - 555LI1 D23 - 561LN2 D48 - 555IE10
 D6 - 555LL1 D24 - 555AP5 D49 - 555IE19
 D7 - 555LN1 D25 - 561LN2 D50 - 555TM8
 D8 - 555LA3 D26 - T34VG1 D51 - 555LA3
 D9 - 555IE10 D27 - 555AP3 D52 - 555LI1
D10 - 555LA4 D28 - 555LN1 D53 - AY38910
D11 - 555TM2 D29 - 555IR22 D54 -
D12 - 555LE1 D30 - 555KP12 KR1818VG93
D13 - 561IE10 D31-D38 - D55 - 555AP3
D14 - 555LE1 K565RU7D
D15 - 561TM2 D39 - 556RT4
D16 - 555LL1 D40 - 555KP12
D17 - 555LA2 D41 - 555LL1
D18 - 555LA4 D42 - 555KP12
D19 - 555TM2 D43 -

                  KR580VV55


  Well, now for the revisions. I must say that all underwritten 
been tested in a real computer by myself. 



             Signal Out Iorq



  What is OUT IORQ? Roughly speaking this
signal IORQ, processed in the controller
Beta Disk'a. It is equal to "1" if it works
TR-DOS and customary IORQ, if everything works
the rest.

  Why does he need? And he needed in order
ports to the disk controller is not in conflict with the ports 
of the standard Spectrum (a they still will conflict: port

Kempston joystick port command register / status VG93 Z80 to 
have the the same address - # 1F). In short, when working

disk controller perefiriynye all other devices disabled in the 
unique setting IORQ 1. 

  In Miko-Best of the signal is not as ULA some makarom tracks
appeal to the TR-DOS itself pinches signals
going to the joystick and keyboard. But if
We picked up by Miko, for example, Sound Drive,
then bydem hear the rustle of the speakers at work DOS'a. And 
all because of the fact that the ports SD intersect with all 
ports of the controller disc. Exit here alone - MAKE OUT IORQ!

There is nothing more to ask: take and mix OR
signal PDM (D19.9) and / IORQ (20-th leg
Z80). At the exit, we have OUT IORQ! Now on
All vnovprisoedinennye device instead of
IORQ need podavat is OUT IORQ.



          Problems Kemston Mouse



  In fact, Kempston mouse and a standard
Spectrum has been in conflict with
Kempston joystick, because these two
Devices are selected on the same
A5. I usually remove such a conflict is simple: Replace A5 in 
deciphering the joystick A6. Although it is possible and A7, 
the joystick is all well, it just so yadres -

# 1F =% 00011111. Such an approach may not
quite literate, but works fine.

  So, I wanted to do in Miko as always:
change A5 to A6. But there it was! It turned out that 555AP3, 
which made the joystick interface, and more pumped via a data 
port # FF mode DOS, and manages the AP3-it is still the same 
ULA. AND here's what I pridunal:


RDKEMP (D26.27) X D27.1


                   February 2000
 A6 1 3 January 2001
/ RD 1 April

              / PDM 1 S 555

        OUT IORQ 15oOE KP11



  I think that everything is clear: if it works
DOS, then we have control of the ULA, and if
No, we have control from a slightly different decoder. That's 
all. 



               Memory 256K



  To get started give layout Dumb
bits of port 220 (# DC), used in Miko for "resource control":


   7 65 4 3210 - bits of port # DC


                D0-D3 - page number

                which will be imprinted with

                address # 8000. Better not to use
                Experiencing the fate of all time
                keep me here 2.

                D4 - number of additional

                set of eight banks.

                D5-D6 - it is not clear, it is better

                keep 11.

                D7 - if 1, then the map
                is the screen from the 13th (# 0D)

                Bank.


  Analyzing with the layout of the port, I
thought, why not make Miko
Pentagon 256K 256K? No sooner said than done:

RAM3 (D43.13) X D42.13


                   February 2000
 PA6 (D43.38) March 2001

         +5 V \ 1 April

         GND \ 1 S 555

                  15oOE KP11



  Thus, in one position switch on
multiplexer D42 gets the same RAM3 (D4
Port # DC), and in another - D6 port # 7FFD
(6-th digit of the port A VV55). After all these
manipulations we get two in one: Pentagon
256 'Miko 256 and do not need any programs to change - and just 
sit klatsat breaker switch. 

  Yet I have observed one interesting
Special Effect: The value entered in the port
# DC, can be read at the same address komandaoy IN. Although I 
do not know if that helps someone.


  And now digression about the memory. I had seen a very
strange pattern memory expansion
domestic Spectrum-compatible machines.
All the homemade versions that do not
supposes mass production, trying to
adhere to standards Dumb ports
expansion, take for example Pentagon 512K -
Port # 7FFD. And for the components that are mass produced, 
standard completely absent, then how many models and ports 
(ATM, Profi, Scorpion, Miko ...). I believe that the reason 
that the artisans that make everything for yourself, try not to 
go beyond framework of standards for compatibility with existing

existing software. A
Here are people who forge the mass production sometimes 
sacrificed for the sake of compatibility illusory benefits in 
two or three ruble. Is it really so hard to think about before

how to draw? After all, avaricious pays
twice (remember Zonova, forced all
well done on Scorpio lock button
Port # 1FFD). Although there is another version,
that all these firms thus raising
prestige: that we all own, we did nothing stolen.



                 Epilogue



  Draw all this I got into the bins,
to find "555 ke-pe 11, dve thing." AND
how do I oblamalsya, finding only one KP12.
And now a question for all who are different KP11
by KP12: how to do everything on vysheopisanoe
one instead of two KP12 KP11? To those who
call first and give the right answer
will do everything pribabahi for Miko's free!

  Phone number for questions and answers: (0322)
67-60-45 (Vladimir).


                             Hacker Rasp