TELEDISK Problem - test-drb@ccmp.vtda.org

12 May 2001

From: joe &lt;rigdonj(a)intellistar.net&gt;

...
      I swapped my 1.2mb drive for a Teac 360k drive. 
No difference. I
tried both BIOS and Direct settings  with no difference. I'm running MS_DOS
...
 and rebooted with NO drivers or TSRs but nothing helps.
 The one odd thing

That will not work.  RX50 is 96tpi and ALL 360k drivs are 48TPI, a non
starter.

The TEAC FD55GFV is the same drive DEC used (RX33) which is 1.2mb
and RX50 (400k single sided) compatable.  The trick is getting the
controller
and drive to interface right and the software should follow.

...
 know it seems to be working for nearly everyone else
but Teledisk simply
will not work for me! My only guess at this point is that perhaps it's
incompatible with my FD controller IC. But BIOS should isolate it from
that, so who knows. 

Some FDCs cannot do the 10 sector format, end game.  Actually most
765 based designs are not best suited as the GAPs and IRGs are very
small (below reasonable).  The DEC designs Pro, Rainbow, Decmate,
VT180 used  WD1793 (not used on PCs) and only the PDP-11/VAX
designs used a 765 biased (SMC9224) design for the MSCP controller
(RQDX) which could format and read/write the RX50.

Hoep that helps some.  Me I'd try a different (meaning secondary)
disk controller in the same 486/100 box.