Notes and Musings on the DAVIAC Relay Computer

After much hard work, the DAVIAC2 now has a BASIC interpreter, here's a sample:

  RUN
  A,B,C,D
  -1,9,2,0
                                                                              *
                                                                  *
                                                         *
                                                  *
                                             *
                                          *
                                        *
                                        *
                                        *
                                         *
                                           *
                                            *
                                             *
                                              *
                                             *
                                            *
                                        *
                                    *
                             *
                    *
        *
 END
 LIST

 10 INPUT "A,B,C,D" A,B,C,D
 11 REM
 20 LET X=-20
 21 REM
 30 LET I=X*X,J=B*I
 31 LET K=I*X,L=A*K
 32 LET M=C*X
 33 LET N=L+J,N=N+M,O=N+D
 34 LET O=O/20
 35 REM
 40 LET P=O+40
 41 IF P<0 GOTO 80
 42 IF P>79 GOTO 80
 43 REM
 50 LET I=0
 51 IF I=P GOTO 60
 52 PRINT " ":
 53 LET I=I+1
 54 GOTO 51
 55 REM
 60 PRINT "*"
 61 GOTO 90
 70 REM
 80 PRINT ""
 81 REM
 90 LET X=X+1
 91 IF X<21 GOTO 30
 99 END
 
 28 Lines of 32
 333 Bytes used of 512 available````

The DAVIAC2, a 74-series logic chip implementation of the DAVIAC computer is in the protoype stage. The latest board version has been populated and is running at 1.8432MHz, this along with the vastly increased RAM allows it to be a much more useful computer!

Some updated renders of the boards are available on the main site: https://daviac.net/DAVIAC-2.php

Check it out!

The assembler has been made available at on the Programming page.

We have a DOS executable, python 2 and python 3 versions. Check it out!

Welcome to DAVIAC. The purpose of the DAVIAC1 Relay Computer it simply to re-demonstrate the most basic principles of computing in a highly visual way in which every bit can be tracked continuously. To this end I have chosen large format relays with easily visible contacts inside clear transparent cases. The single pole SPDT (single pole double throw) examples have 12V coils and 240V, 10A contacts. These relatively large power relays provide not only the visual evidence of operation, but also a most satisfactory sound. I had a very clear idea of the sound I wanted, and am very happy with the result. See : https://youtu.be/93PHxVpPLxA?si=ObRfHIE1dPXGfivS There are more YouTube links on www.daviac.net and more will be uploaded soon.