From: asc135@yahoo.com   
      
   Hello!   
      
   Knut wrote:   
   >   
   > µPD765a, is that a common fd controller to be used/emulated inside   
   > chipsets? Isn't the fd controller integrated in the chipset, probably   
   > emulating something that existed before?   
      
   The NEC µPD765 was the original floppy diskette controller from which   
   the intel 8272 was licensed (the first FDC controller in the original   
   IBM-PC).  All IBM and compatible computers since then have controllers   
   that are descendants of that and more or less software compatible.  As   
   time went on more and more support circuitry became integrated and   
   eventually the entire thing became part of the "super-i/o" part on   
   system motherboards.   
      
   > I did check on some cards I have here next to me. On one of them there   
   > is a GD82C765B, might it be the same but goldstar rather than nec? That   
   > is an Acculogic sIDE-3 ISA bus first/second IDE type card with a floppy   
   > interface too when used as first IDE... There were also two adaptec   
   > cards that sports floppy interface (likely fd controllere PC8477B and   
   > DP8473A). These adaptec cards are supposed to be able to read/write   
   > model-I single density, with the strange DAMs (1542A and 1522A). I   
   > should try that... it might make it easier to recreate real SD disks.   
      
   All those you mentioned are 765 compatible.  The Adaptec cards are   
   single density capable, but CANNOT read or write the FD1771 compatible   
   DAMs (0xF9, 0xFA) used by TRSDOS 2.3.  In fact, no 765 family part   
   supports those DAMs.  Later Western Digital parts like the FD179x, etc.   
   could read but not write them.  Only the Catweasel supports them in   
   modern times since all encoding and decoding is in the software.   
      
   Best regards,   
   Amardeep   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)