FOSBIC1 compiler

Or Basic compiler/system in Fortran IV

I came across fosbic1 on github by accident, so intrigued by the description:

This is the FOSBIC1 compiler developed at the University of Gießen, Germany
in the late 70s for the CDC 3300 batch system.

It is a BASIC compiler and runtime system which is written in FORTRAN IV.

The text book from which the source code was copied implies that it is
a modified version of a BASIC compiler named UWBIC from the University of Washington, developed by William Sharp in 1967, for their IBM 7094.

So, without going into it much further I went ahead and made a few minor changes to get it running on Microsoft Fortran


Instead of some boring example, I thought I’d try some Mandelbrot, so going through this collection on rosettacode, I thought the OS/8 version looked simple enough to work with.

Sadly it doesn’t seem to be very ASCII so it doesn’t understand numerical characters. Maybe I’m doing it wrong I didn’t see anything. Just as my attempt to set a string variable to itself + a new letter then print that string strangely failed. Also it does weird stuff with strings, again it maybe me, but I’m impatient. This is terrible, and yeah I know.

                                        TESTCOMPILER -- BASIC BWL 5 GIESSEN -- VERSION 6/76-04

                   10 X1=59
                   11 Y1=21
                   20 I1=-1.0
                   21 I2=1.0
                   22 R1=-2.0
                   23 R2=1.0
                   30 S1=(R2-R1)/X1
                   31 S2=(I2-I1)/Y1
                   40 FOR Y=0 TO Y1
                   50 I3=I1+S2*Y
                   60 FOR X=0 TO X1
                   70 R3=R1+S1*X
                   71 Z1=R3
                   72 Z2=I3
                   80 FOR N=0 TO 30
                   90 A=Z1*Z1
                   91 B=Z2*Z2
                   100 IF A+B>4.0 GOTO 130
                   110 Z2=2*Z1*Z2+I3
                   111 Z1=A-B+R3
                   120 NEXT N
                   130 REM PRINT CHR$(0062-N);
                   131 IF N=0  THEN 200
                   132 IF N=1  THEN 202
                   133 IF N=10 THEN 204
                   134 IF N=11 THEN 206
                   135 IF N=12 THEN 208
                   136 IF N=14 THEN 210
                   137 IF N=15 THEN 212
                   138 IF N=16 THEN 214
                   139 IF N=17 THEN 216
                   140 IF N=19 THEN 218
                   141 IF N=2  THEN 230
                   142 IF N=20 THEN 232
                   143 IF N=22 THEN 234
                   144 IF N=23 THEN 236
                   145 IF N=24 THEN 238
                   146 IF N=25 THEN 240
                   147 IF N=3  THEN 242
                   148 IF N=30 THEN 244
                   149 IF N=31 THEN 246
                   150 IF N=4  THEN 248
                   151 IF N=5  THEN 250
                   152 IF N=6  THEN 252
                   153 IF N=7  THEN 254
                   154 IF N=8  THEN 256
                   155 IF N=9  THEN 258
                   200 PRINT 'A';
                   201 GOTO 439
                   202 PRINT 'B';
                   203 GOTO 439
                   204 PRINT 'C';
                   205 GOTO 439
                   206 PRINT 'D';
                   207 GOTO 439
                   208 PRINT 'E';
                   209 GOTO 439
                   210 PRINT 'F';
                   211 GOTO 439
                   212 PRINT 'G';
                   213 GOTO 439
                   214 PRINT 'H';
                   215 GOTO 439
                   216 PRINT 'I';
                   217 GOTO 439
                   218 PRINT 'J';
                   219 GOTO 439
                   230 PRINT 'K';
                   231 GOTO 439
                   232 PRINT 'L';
                   233 GOTO 439
                   234 PRINT 'M';
                   235 GOTO 439
                   236 PRINT 'N';
                   237 GOTO 439
                   238 PRINT 'O';
                   239 GOTO 439
                   240 PRINT 'P';
                   241 GOTO 439
                   242 PRINT 'Q';
                   243 GOTO 439
                   244 PRINT 'R';
                   245 GOTO 439
                   246 PRINT '-';
                   247 GOTO 439
                   248 PRINT 'T';
                   249 GOTO 439
                   250 PRINT 'U';
                   251 GOTO 439
                   252 PRINT 'V';
                   253 GOTO 439
                   254 PRINT 'W';
                   255 GOTO 439
                   256 PRINT 'X';
                   257 GOTO 439
                   258 PRINT 'Y';
                   259 GOTO 439
                   439 REM
                   440 NEXT X
                   450 PRINT '-EOL'
                   460 NEXT Y
                   461 PRINT 'END'
                   470 END

It runs in batches, so it’s not interactive. Very mainframe/1960’s minicomputer like. I guess it’s fitting again being in FORTRAN.

******************* EVERYTHING SEEMS OK -- LET'S GO AHEAD

                    PERCENT OF AVAILABLE STORAGE USED               31.081
                    PERCENT OF AVAILABLE DATA STORAGE USED            .000

AA    A    A    A    A    B    B    B    B    B    K    K    K    K    K
K    K    K    K    K    K    K    K    K    K    Q    Q    Q    Q    Q
Q    T    T    T    U    X    F    D    E    T    Q    Q    Q    Q    K
K    K    K    B    B    B    B    B    B    B    B    B    B    B    -EOL

I’m not sure what is up with the AA and after that, it’s all tabulated. I ended up running it through sed to remove the spaces, and using notepad to stitch the lines together. I guess I could have bash’d it some more but.. I’m impatient.

So yeah, it looks like it worked! Very amazing. And of course it’s crazy fast but that should be expected I suppose. I don’t like the hard coded table, but I just wanted to get it to generate an image.

Sadly, the author of the compiler, Weber seems to have disappeared, and the publisher Paul Haupt died in 1978, a year after this being published.

One thought on “FOSBIC1 compiler

  1. Interesting, I never heard of this even though I was a PhD student in Marburg, about 30 km north of Gießen (but, of course, decades after that BASIC compiler was written).

    Amazingly, this work was done in the economics department – Gießen didn’t have a CS department back then and still today only has two professors working in CS. There’s a German newspaper article on FOSBIC praising the research results at

    Weber is not mentioned as emeritus professor at the economics department of the university of Gießen, so he might have left Gießen before retiring. According to Weber was 61 years old in 1988, so he would be around 96 years old today if he is still alive.

    The other person mentioned in the readme is “DIPL.-ING.,DIPL.-OEC.C.W.TUERSCHMANN”. It seems this is Carl Wolfram Türschmann (the name is pretty rare in Germany, you can also find a LinkedIn profile “Wolfram Türschmann” that mentions Gießen uni, so I assume this is him) who also published a textbook on BASIC with Karl Weber (

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