S P E C T R U M    

                       [  S O F T R O M  ]

                       ===================

  		    INTERFACE 1 MODIFICATIONS
		    =========================

The SOFT-ROM is incompatible with Interface 1. The reason for 
this is that when the SOFT-ROM is paged in both the INTERNAL 
SPECTRUM ROM and the SHADOW ROM in Interface 1 are disabled and 
although the SOFT-ROM will still function, no Interface 1 
functions will be available when in SOFT mode. 

The answer to the problem is to use the ROMCS line from 
Interface 1 to temporarily page out the SOFT-ROM. This can be 
achieved by diverting ROMCS to the spare edge connector pad 28A, 
which is now a disable line on the SOFT-ROM. 

THIS MODIFICATION MAY INHIBIT OTHER ROM BASED EQUIPMENT! 

The modification steps are :- 

(a) Cut out a small section of the PCB track to the edge 
    pad 25B (underside at rear of Interface 1).

(b) Cut the leg of the edge connector to 25B into the 
    Spectrum (be careful not to bend the 'A' row too far 
    to reach the 'B' row). 

(c) Make a wire connection from the 25B pad to the Spectrum 
    side of the cut 25B leg and insulate. 

(d) Make a wire connection from the bottom part of the 25B 
    leg (solder point under PCB) to pad 28A an the top side 
    rear of the PCB. 

(e) For Interface 1 to work without the SOFT-ROM in place 
    mount a DIODE (lN4148 only) to bridge the cut leg 25B. 

(f) Check your work being especially careful to remove any 
    solder splashes or bridges as it is very easy to damage 
    both the Interface 1 and the Spectrum! 

N.B. These notes are for your information and I (P.G.) will 
not be held responsible for any equipment failure caused by 
any person following these guide lines. 

			DIAGRAMS
			-------- 

see soft07.gif (Image 3)


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