SimH DECtape vs. Tops-10 [was RE: Writing emulators [Was: Re: VCF PNW 2018: Pictures!]]

Glen Slick glen.slick at
Mon Feb 26 14:52:02 CST 2018

On Mon, Feb 26, 2018 at 12:19 PM, Paul Koning via cctalk
<cctalk at> wrote:
> Another example is the work pdp2011 had to do in order to make RSTS boot on that FPGA based PDP-11 emulation, because RSTS was doing some CPU-specific hackery to test for an obscure CPU (or FPU?) bug that had been corrected in some ECO that it wanted to require.  The only way to figure out how to do that is to reverse engineer that particular bit of code, which isn't normally available in source form.

I have one M8190 KDJ11-B that caused an RSTS/E 10.1 installation
failure. I forget what the error message was. Looking at an
installation tape message maybe it was one of these strings.
Unfortunately I could not contact field service to correct the

ECOs are missing from this FPJ11.
This DCJ11 cannot be used in conjunction with an FPJ11 accelerator.
Contact Field Service for FCO kit EQ-01440-02 to correct the problem.
The floating exception ECO is missing from this FPJ11.

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