From: RDC@oz.org   
      
   Hi Ken,   
      
   "Kallikak"  wrote in message   
   news:1180746272.943305.92000@z28g2000prd.googlegroups.com...   
   >   
   > That's an unwanted complication...  I have mailed to check.  I presume   
   > from your description that the 6670 is the character generator ROM?   
   > Also, any thoughts on the sellers comment that the fault used to   
   > affect only half the screen?   
   >   
   > Ken   
   >   
   Yes, 6670P is the chr gen rom.   
      
   If the fault only affected the left hand side of the screen at one point,   
   this is good news as it would   
   suggest the char gen rom is NOT faulty.   
      
   When in the left side of the screen, signal C32 from Z50 (ls93) should be   
   LOW.   
   Pin 11 (goes high after 64 chars have been displayed) of Z50 is what clocks   
   the   
   aforementioned Z12 to produce the horizontal row signals.   
      
   At first glance it would suggest both Z50 and Z12 have failed.   
      
   I have seen a number of M1's with failed LS93s in the divider chain, so I   
   wouldn't be too   
   worried about it if I were you.   
      
   Incidentally, I am in Sydney if you end up buying it and have difficulties   
   getting it going.   
      
   Leslie   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)