v1.25/Tim_Paterson_16Dec2013_email.txt

   1 From: Tim Paterson
   2 To: Len Shustek
   3 Date: Mon, 16 Dec 2013 10:34:17 -0800
   4 Subject: RE: Source code to MS-DOS 1.0
   5
   6
   7 I have found and attached the source code for MS-DOS 1.25 as shipped by Seattle Computer Products.  Version 1.25 was the first general release to OEM customers other than IBM so was used by all the first clone manufacturers.
   8
   9 IBM's DOS 1.1 corresponds to MS-DOS 1.24.  There is one minor difference between 1.24 and 1.25, as noted in the revision history at the top of MSDOS.ASM.
  10
  11 Of the file attached, only STDDOS.ASM/MSDOS.ASM (DOS main code) and COMMAND.ASM (command processor) would have been used by an OEM other than Seattle Computer.  The other files:
  12
  13 IO.ASM - I/O system unique to SCP (equivalent to ibmbio.sys).
  14 ASM.ASM & HEX2BIN.ASM - Old 8086 assembler developed by SCP (used to assemble older version of DOS).
  15 TRANS.ASM - Z80 to 8086 assembly source code translator developed by SCP.
  16
  17 I also have a 6\94 stack of printouts of assembly listings for some of these and probably other related programs.
  18
  19 Tim Paterson
  20 Paterson Technology
  21 http://www.patersontech.com/
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  23