From: jjhudak4@gmail.com   
      
   On Thursday, July 6, 2023 at 7:05:47 PM UTC-4, John Robertson wrote:   
   > On 2023/07/06 2:30 p.m., Tony wrote:    
   > > Looks like these threads are years old so this will probably never be    
   > > read! I designed the receiver. There is no service manual, unless one    
   > > was done after I left the company. The receiver was calibrated    
   > > automatically by computer over the rs 232 port before the units were    
   > > shipped. The calibration points were stored in eprom. Depending on the    
   > > year of manufacture there was a backup battery or 1 farad cap as backup.    
   > > As the original spec was 10 years receiver life most receivers have now    
   > > probably died. The cal software ran on a BBC micro. Any programming info    
   > > is long gone.    
   > >   
   > Talk about planned obsolescence!    
   >    
   > So the receiver calibration might change over time and there is    
   > absolutely no way to fix this as there is no calibration program left    
   > anywhere. I/m assuming if anything was changed in the receiver that it    
   > would then need calibration...    
   >    
   > And people wonder why I like fixing electronic toys prior to the 2000s!    
   > Stuff after 2000 is not nearly as fixable - too many one-off or customer    
   > parts.    
   >    
   > Then there is the question of who owns the device they bought. As an    
   > example one brand of pinball games shuts the game down if it is operated    
   > on 50 or 60 Hertz and that is different than the line frequency    
   > (60/50Hz) that the game was originally set up for.    
   >    
   > John :-#(#    
   > --    
   > (Please post followups or tech inquiries to the USENET newsgroup)    
   > John's Jukes Ltd.    
   > #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3    
   > (604)872-5757 (Pinballs, Jukes, Video Games)    
   > www.flippers.com    
   > "Old pinballers never die, they just flip out."   
      
   This makes me wonder if this end state of calibration data vanishing after xx   
   years was a design requirement (specified by who?) or a byproduct of the   
   design approach taken (to increase machine flexibility? reduce parts count?   
   etc.).     
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)