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
                    PERCENT OF AVAILABLE NUMBERED STATEMENTS USED   30.294

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.