From: nopes@none.com   
      
   Disregard. All working now.   
      
   There was a bad track on one of the address lines and I also made the   
   mistake by burning the rom at offest $0000 instead of at $4000.   
      
      
   "Sam"  wrote in message   
   news:478b26cb$0$86717$c30e37c6@pit-reader.telstra.net...   
   > Hi all.   
   >   
   > Just reviving my old thread for reference below.   
   >   
   > I bought a cheap 1541-II of ebay, pulled the ROM out of it and put it in   
   > my broken drive and   
   > presto, it worked. I must have toasted my old drive in the process of   
   > pulling out the 6502, 6522's  and   
   > static RAM chip to install sockets, serves me right for not wearing an   
   > anti-static wrist strap.   
   >   
   > Now the question is, how do I burn a new rom ?   
   >   
   > I have a LV48 programmer and bought some M27C256 chips but it seems I am   
   > not writing   
   > the image correctly. Ray Carlsen's page specifies that the ROM reads as a   
   > M27C128, however   
   > I am not able to find them so I'm using the 256 instead.   
   >   
   > Are there any doc's out there on how to do this ?   
   >   
   > Cheers.   
   >   
   > "Sam"  wrote in message news:...   
   >> Hi Guys,   
   >>   
   >> I am still working on a 1541II drive and have some questions, but first   
   >> of all I would like to explain   
   >> the symptoms I was having and what I had done & have been doing.   
   >>   
   >> 1. Symptom   
   >>        * When the drive is powered on, the spindle runs continuously and   
   >> the LED stayed on.   
   >>    Action   
   >>        * Replaced 6502 chip   
   >>   
   >> 2.  Symptom   
   >>        * After replacing the 6502 and powering on the drive, the drive   
   >> led now flashes slowly every 2 seconds.   
   >>     Action   
   >>         * Replaced static RAM chip LC-3517A with the same type.   
   >>   
   >> After performing those 2 actions I am now experiencing Symptom 1 again. I   
   >> thought the replaced 6502 may have been damaged again, but I have several   
   >> 6502 spares that I tried.   
   >>   
   >> Now I am beginning to think that I may have damaged the ROM, tt reads   
   >> fine in my programmer as a 27128. The problem is that the binary produced   
   >> does not match with other 251968-03 I eproms I have downloaded, there are   
   >> many side by side differences and CRCs come out different. Were there   
   >> different versions of the ROM with 251968-03 ?   
   >>   
   >> My dumped rom produced CRC32(0xf455d750)   
   >> Downloaded ones all produced CRC32(0x899fa3c5)   
   >>   
   >> I can't find any info on different versions of the 251968-03. So   
   >> hopefully the rom is stuffed and I can just burn a new one, your thoughts   
   >> ?   
   >>   
   >> Cheers,   
   >> Sam   
   >>   
   >   
   >   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)