Elektronika MK-85/M
Elektronika MK-85C

© Gregory Escov

© Andrew Davie

"The MK-85 is a CMOS BASIC calculator, more than loosely based on a very similar Sharp. This genre sort of died out, and I think MK-85 is the only one still in production. Looks like other MKs -- silver and flat, with an LCD. Main differences are QWERTY keyboard and pixel-addressable single-line display. A friend of mine was on a team which designed it/reverse engineered Sharp. MK-87, MK-85 and a few others were based on common CPU. "

- Alexei

Elektronika MK-85 is, perhaps, the most advanced Russian/Soviet handheld calculator that ever hit the markets. There were rumors about MK-87 (that was supposed to combine calculator and notebook/databank features), and I have seen a prototype of MK-90 myself, but, still, MK-85 is the most advanced thing that I ever saw on the shelves.

© Gregory Escov

When MK-85 came out, the pricing politics in Russia had already changed from old socialistic stubbornness. To put it simply, the ruble was rapidly falling down, and the shops were free to increase prices accordingly. I have seen MK-85 from 300-420 rubles all over 1991, and when, finally, I persuaded my parents to lend me some money to buy it (in the winter of 1992), it cost 600 rubles - about $100, if I remember correctly. The price given on the back of machine is 145 rubles.

MK-85 was a modification of all the typical western BASIC machines. It had 9 slots for user programs (P0-P9), user could run (switch to) any one of them by pressing S(hift)+P0...P9. The immediate (program running) mode was called by MODE-0, program writing by MODE-1. Sound familiar? Right, I've seen tons of CASIOs that used the same sequences. Trust me, MK-85 was copied from one of those. I've never encountered 1221 memory bytes on a western machine, though, so THAT at least is our own doing!

Now, to differences. MK-85 actually could address any pixel on its 12-symbol display separately (unlike all CASIOs I've seen). Of course, the "symbols" on the display stood apart from each other, so the graphical display was NOT pretty. I did use it in my differential equation class, though, and I did write a shoot-them-up game for it. So that was one cool feature, at least.

Another cool thing thing was the sheer number of various special-key combinations. I think that here MK-85 would overpass everything I've ever seen, including (!) even Russian ZX-Spectrum. See for yourself:

You could simply press a letter-key : QWE
You could press S(hift) and then a letter-key : !"#
You could press F(unction) and then a letter-key : SET MODE VAL
You could press MODE and then a letter-key : qwe

And, if you did not have enough, you could also enter "extended" mode (MODE+".") and then try all the same variations :

Letter - small Russian ones ("ja-w-e", translated as "to Java" :)
Shift+Letter - special symbols (%'@, not printed on keyboard)
Function+Letter - strangely, big latin letters again (QWE)
Mode+Letter - big Russian ones ("JA-W-E")

Of course, that doesn't cover those four Russian letters to the right of the calculator (there are 33 Cyrillic letters, if you didn't know!) Those were entered slightly differently : for example,

MODE+"*" gave you "big" CH letter
MODE+"." MODE+"*" gave you a little one.

Neat eh?

Another thing I liked about MK-85 is CHR$() function, that could translate a 1-191 (note the range!) number into a symbol. Strangely, I've never seen that one on a western handheld machine.

Well, that would be enough about the good/cool sides of Russian BASIC computing. I must tell the world about the BUG. I think it was a bug in its ROM card; certainly all others MK-85 I've seen did not suffer from it. Still, when I tried to contact the manufacture and fix it (change the fucking card), they said that they can't do anything because they're out of stock for ROMs. Sad.

So, here's a description of this Bug. When you entered any line into the computer and pressed EXE (that's ENTER for PC kids), it appeared to check its length. And, if it was more than 32 (!) characters - OOPS! Instead of doing anything with the line, it scrolled your text to the right (too quickly to read), and when, after half a second, display settled, you could read an Apocalyptic Message from Nodding God : <9000e2001, with cursor blinking happily in the rightmost position (you could clear this line by AC). Whatever that means, think for yourself. I'd quite sure that the meaning is that our world existed for 9000 years, and the End will come in 2001. So - let us pray. Pray that every bastard who allocates a buffer for 32 characters, when his own ROM includes an editor for 128-char line, should be drawn, tortured and forced to use Windows-95. Jawohl, Amen, or Slava KPSS - whatever!

- © Gregory Escov


© Sergei Frolov

Secret Military Versions

Tetris on MK-85!

                        Tetris for the MK-85 !!!!


1 DEFM 9:VAC:G=1111111:GOTO 50
2 E=E-2
3 E=E+1:RETURN
4 B=C:RETURN
5 F=2:RETURN
6 F=3:RETURN
7 F=1
8 C=C+1:FOR D=E TO E+F-1:G(C)=G(C)+10^D:NEXT D:RETURN
9 IF C<B+1;C=B+1
10 C=C-1:RETURN
11 IF C<B+2;C=B+2
12 C=C-2:RETURN
13 GOSUB 2:GOTO 16
15 F=1
16 FOR C=24 TO 0 STEP -1:IF G(C)=0;NEXT C
17 IF FRAC(INT(G(C)/10^E)/10^F)=0;GOSUB 10:GOTO 17
18 RETURN
50 A=INT(RAN#*15+1):GOSUB 98:FOR B=10 TO 5 STEP -1
55 FORC=1TO25:CSRB,:LETC$:PRINTCHR96;:D=ASCIKEY:IFD=83;GOSUB98
60 IF D=87;IF MID(1,1)="0";$=$+"0":$=MID(2,7):GOSUB 3
65 IF D=88;IF MID(7,1)="0";$="0"+$:$=MID(1,7):GOSUB 2
70 IF D=65 THEN 72:NEXT C:NEXT B
72 Z(8)=Z(9)
73 IF Z(8)>390;Z(8)=Z(8)-380:GOTO 73
75 Z(9)=Z(9)+4:CSR 5,:DEFM 24:CSR 11:PRINT CHR(Z(8)/10);
78 FOR Z(6)=1 TO 7:Z(7)=ASCIGETC(Z$(A+9),Z(6))/10
80 GOSUB INT Z(7):GOSUB 10*FRAC Z(7):NEXT Z(6):DEFM 9
81 IF C>24;CSR.,:PRINT "Game over",Z(9):GOTO 1
82 Z(6)=C-4
83 FOR E=Z(6) TO C:A=G(E):FOR F=0 TO 6
85 IF FRAC(A/10)=0;DRAWC E,F:GOTO 88
86 DRAW E,F
88 A=INT(A/10):NEXT F:NEXT E:FOR E=1 TO 24
90 IF G(E)=G;FOR F=ETO23:G(F)=G(F+1):NEXTF:Z(6)=E:C=24:GOTO 97
92 NEXT E:GOTO 50
97 Z(9)=Z(9)+7:Z(5)=0:GOTO 83
98 GOSUB 99+A:A=A+1:F=LEN$:E=5-F:$="00"+$+"000":$=MID(1,7)
99 RETURN
100 $="232":RETURN
101 $="72":RETURN
102 $="262":RETURN
103 $="27":A=0:RETURN
104 $="4444":RETURN
105 $="0F":A=4:RETURN
106 $="66":A=6:RETURN
107 $="C6":RETURN
108 $="264":A=7:RETURN
109 $="462":RETURN
110 $="6C":A=9:RETURN
111 $="E2":RETURN
112 $="226":RETURN
113 $="8E":RETURN
114 $="644":A=11:RETURN



DEFM 15
Z$(number)=CHR(.)+CHR(.)+CHR(.)+CHR(.)+CHR(.)+CHR(.)+CHR(.)

 

                Number               Code
                 10       154 185 169  75  87 184 184
                 11       168  37 184 184 184 184 184
                 12       183 154 139  38  25  83 187
                 13       183 154  26 169  37  26 188
                 14       158  88 188 184 184 184 184
                 15       168 184 184 184 184 184 184
                 16       168 168 184 184 184 184 184
                 17       185 164  33 159  22  58  38
                 18       183 154 182 169  38  25  87
                 19       154 183 169  28  58  37 184
                 20        53 164 182 159  35  82 188
                 21       168  33 187 184 184 184 184
                 22       183 154 182 163 118  82  58
                 23       154 186 169  76 188 184 184
                 24       168  78 184 184 184 184 184