From: nowhere@never.at   
      
   James Harris asked:   
      
   > I wrote:   
   >> Martin Str|mberg wrote:   
   >> ...   
   >>> So you decide the rules and tell and show us (if you want).   
   >>   
   >> Thanks, I thought real needs caused this restrictions.   
      
   > As someone who has seen the various attempts at writing a decoder I am   
   > not sure what the goal is. I get it that you have been producing code   
   > which uses bytes in the ASCII printable character set but there are lots   
   > of questions.   
   >   
   > What is the basic requirement?   
      
   the challenge was/is to create the shortest possible BASE64 decoder with   
   transferable text to be renamed as a xxx.COM and be executed in DOS.   
      
   > What are the initial conditions, i.e. what do you know about registers   
   > at entry?   
      
   know register in DOS.com files are SS=DS=ES=CS SP=FFFE or less [SP]=0.   
      
   > What's the minimum number of bytes you can count on before you might get   
   > to a CR or CR/LF?   
      
   I think we agreed on 64-characters/line but it can be more or less or   
   even reflown during transfer. So we got to skip any space, tabs CR/LF.   
      
   > Can you overwrite the original text with the decoded version?   
   yes.   
      
   > If not, what options can be used to get memory to decode into?   
      
   nothing, DOS.com is limited to ~63.5 KB. I use PSP CS:040.. for decoder.   
      
   > In addition, I could guess there might be problems with the location of   
   > the decoded code. So I guess it is meant to be started at CS:0 or   
   > CS:100. Am I anywhere close?   
      
   The challenge implied that the final decoded stuff starts at CS:0100   
   and run (or as additional challenge to be stored) as a .com-file.   
      
   >> So my rules for such an Base64 decoder would allow ASCII 33..127 and   
   >> nothing less than 386 code.   
      
   > You know you want to use 8086 code really.... :-)   
      
   I'm much older than 8080, but I wont enter the museum to run my code.   
   __   
   wolfgang   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)