Writing emulators (was Re: VCF PNW 2018: Pictures!)

[Guy Sotomayor Jr]

> On Feb 21, 2018, at 12:19 PM, Rich Alderson via cctalk <cctalk at classiccmp.org> wrote:
> 
> From: Guy Sotomayor Jr
> Sent: Wednesday, February 21, 2018 11:24 AM
> 
>>> On Feb 21, 2018, at 10:59 AM, Paul Koning via cctalk <cctalk at classiccmp.org>
>>> wrote:
> 
>>> Typically you'd emulate the I/O device functionality, regardless of whether
>>> that is implemented in gates or in co-processor firmware.  That's the
>>> approach taken with the MSCP I/O device emulation in SIMH, or the disk
>>> controller emulation in the CDC 6000 emulator DtCyber.
> 
>> It’s also what’s done in Hercules (S/370, 370/XA, 390, Z simulator) and the
>> mainframe I/O is complex to say the least.
> 
> Also the method used by the KLH10 emulator (KS-10, KS-10/ITS microcode, KL-10).
> There, each device type runs in a separate fork, using System V style memory
> mapping.  This of course means that it only runs under certain Unix variants.

I haven’t looked at KLH10 in a long time, but Hercules runs on a lot of different platforms
including Windows (and I would not call that a Unix variant by any stretch of the imagination).

TTFN - Guy