I have some old domain names registered as early as year 1995 e.g. KING.NET, CITYWARE.COM, INXNET.COM, etc., but not close to year 1985 where the first 100 domains were registered. Now after 20+ years, these domain names range from US$500,000.00 to $10,000,000.00 in domain market.

Here are the list courtesy by Gene (MrCommission.com) known in Namepros community:

The first 100 .com domain names:
03/15/1985 SYMBOLICS.COM
04/24/1985 BBN.COM
05/24/1985 THINK.COM
07/11/1985 MCC.COM
09/30/1985 DEC.COM
11/07/1985 NORTHROP.COM
01/09/1986 XEROX.COM
01/17/1986 SRI.COM
03/03/1986 HP.COM
03/05/1986 BELLCORE.COM
03/19/1986 IBM.COM
03/19/1986 SUN.COM
03/25/1986 INTEL.COM
03/25/1986 TI.COM
04/25/1986 ATT.COM
05/08/1986 GMR.COM
05/08/1986 TEK.COM
07/10/1986 FMC.COM
07/10/1986 UB.COM
08/05/1986 BELL-ATL.COM
08/05/1986 GE.COM
08/05/1986 GREBYN.CO
M08/05/1986 ISC.COM
08/05/1986 NSC.COM
08/05/1986 STARGATE.COM
09/02/1986 BOEING.COM
09/18/1986 ITCORP.COM
09/29/1986 SIEMENS.COM
10/18/1986 PYRAMID.COM
10/27/1986 ALPHACDC.COM
10/27/1986 BDM.COM
10/27/1986 FLUKE.COM
10/27/1986 INMET.COM
10/27/1986 KESMAI.COM
10/27/1986 MENTOR.COM
10/27/1986 NEC.COM
10/27/1986 RAY.COM
10/27/1986 ROSEMOUNT.COM
10/27/1986 VORTEX.COM
11/05/1986 ALCOA.COM
11/05/1986 GTE.COM
11/17/1986 ADOBE.COM
11/17/1986 AMD.COM
11/17/1986 DAS.COM
11/17/1986 DATA-IO.COM
11/17/1986 OCTOPUS.COM
11/17/1986 PORTAL.COM
11/17/1986 TELTONE.COM
12/11/1986 3COM.COM
12/11/1986 AMDAHL.COM
12/11/1986 CCUR.COM
12/11/1986 CI.COM
12/11/1986 CONVERGENT.COM
12/11/1986 DG.COM
12/11/1986 PEREGRINE.COM
12/11/1986 QUAD.COM
12/11/1986 SQ.COM
12/11/1986 TANDY.COM
12/11/1986 TTI.COM
12/11/1986 UNISYS.COM
01/19/1987 CGI.COM
01/19/1987 CTS.COM
01/19/1987 SPDCC.COM
02/19/1987 APPLE.COM
03/04/1987 NMA.COM
03/04/1987 PRIME.COM
04/04/1987 PHILIPS.COM
04/23/1987 DATACUBE.COM
04/23/1987 KAI.COM
04/23/1987 TIC.COM
04/23/1987 VINE.COM
04/30/1987 NCR.COM
05/14/1987 CISCO.COM
05/14/1987 RDL.COM
05/20/1987 SLB.COM
05/27/1987 PARCPLACE.COM
05/27/1987 UTC.COM
06/26/1987 IDE.COM
07/09/1987 TRW.COM
07/13/1987 UNIPRESS.COM
07/27/1987 DUPONT.COM
07/27/1987 LOCKHEED.COM
07/28/1987 ROSETTA.COM
08/18/1987 TOAD.COM
08/31/1987 QUICK.COM
09/03/1987 ALLIED.COM
09/03/1987 DSC.COM
09/03/1987 SCO.COM
09/22/1987 GENE.COM
09/22/1987 KCCS.COM
09/22/1987 SPECTRA.COM
09/22/1987 WLK.COM
09/30/1987 MENTAT.COM
10/14/1987 WYSE.COM
11/02/1987 CFG.COM
11/09/1987 MARBLE.COM
11/16/1987 CAYMAN.COM
11/16/1987 ENTITY.COM
11/24/1987 KSR.COM
11/30/1987 NYNEXST.COM

I would like to see the next 200 to 500 domains registered. I will google and will keep you posted.