Plus 1 Conversion

By G. Peake

Originally published in EUG #10

My system is an Elk and Plus 1 with a Slogger Master RAM Board, Pres' AP2, AP6, AP3/4 and, at the moment, I'm building Jafa Systems' Mode 7 Adaptor. In ROM, I have Slogger's T2p4 and Pineapple Software's PCB and DIAGRAM 2. The Pineapple ROMs are for the Beeb, but both work well with the Elk with just a few differences in the keys used. PCB works in Normal (a bit on the slow side) and Turbo modes, while Diagram 2 is very limited in Normal and Turbo modes, but okay in 64K.

I have modified my Plus 1 by fitting a 25-way D-type connector in the top half of the box, above the printer socket. By fitting a short length of ribbon cable with an IDC connector to it and plugging this into the printer socket, a standard IBM PC type printer socket, a standard IBM PC type printer cable can be used to condirect to any IBM PC compatible printer. I have sent instructions on how to make this modification in case anyone else would like to try it. Much neater and more convenient than Beeb-type cables.

  1. Connect approx 3 inches of 26-way ribbon cable to a 26-way IDC connector. Pin 1 is marked by an inverted "V".
  2. Fit the 25-way D-type connector in the top half of the Plus 1's case having cut a suitable hole.
  3. Solder the ribbon cable to the D-type connector as in the following table:-
  4.               ELECTRON                         IBM STYLE PLUG
    
                    PIN                                 PIN
                     1 --------------------------------- 1  
                     2 --------------------------------- 19
                     3 --------------------------------- 2  
                     4 --------------------------------- 19
                     5 --------------------------------- 3  
                     6 --------------------------------- 20
                     7 --------------------------------- 4  
                     8 --------------------------------- 20
                     9 --------------------------------- 5  
                    10 --------------------------------- 21
                    11 --------------------------------- 6  
                    12 --------------------------------- 21
                    13 --------------------------------- 7  
                    14 --------------------------------- 22
                    15 --------------------------------- 8  
                    16 --------------------------------- 22 
                    17 --------------------------------- 9 
                    18 --------------------------------- 23 
                    19 --------------------------------- 10
                    20------------------:
                    21                  :
                    22                  :
                    23                  :--- NOT CONNECTED 
                    24                  :
                    25                  :
                    26------------------:
      
    
  5. Connect the IDC connector to the printer port and re-assemble the Plus 1 case.

G. Peake
British Aerospace, Saudi Arabia