I modified an Odyssey 2 computer so that it runs on solar power. The Odyssey 2 has a 12 VDC power supply; however, this just goes in to a voltage regulator that brings the power down to 5 VDC. So, I am able to run the power down to 10V. I changed the charge control program so that it turns off the Odyssey 2 when the voltage gets to 10V.

Here is a picture:

Here is the assembly listing:

    ;
    ;  8048 Disassembly of solody.bin
    ;  04/20/04 5:25
    ;
    org     0
    ;
    clr     a
    outl    p2,a
    mov     a,#80h
    outl    p2,a
    X0005:  in      a,p1
    mov     r0,#0f2h
    cpl     a
    add     a,r0
    jnc     X001f
    in      a,p1
    mov     r0,#0e3h
    cpl     a
    add     a,r0
    jc      X002f
    jmp     X0005
    ;
    org     1fh
    ;
    X001f:  mov     a,#0a0h
    outl    p2,a
    jmp     X0005
    ;
    org     2fh
    ;
    X002f:  nop     ; data truncated
    ;
    org     32h
    ;
    in      a,p1
    mov     r0,#0a7h
    cpl     a
    add     a,r0
    jc      X003f
    mov     a,#0e0h
    outl    p2,a
    jmp     X0005
    ;
    org     3fh
    ;
    X003f:  in      a,p1
    mov     r0,#0dfh
    cpl     a
    add     a,r0
    jnc     X004f
    mov     a,#0c0h
    outl    p2,a
    jmp     X003f
    ;
    org     4fh
    ;
    X004f:  mov     a,#0e0h
    outl    p2,a
    jmp     X0005
    ;;
    end
    ;
  

Here is an image of the ROM.