[Info-vax] CentOS has been effectively killed for production use

[Arne Vajhøj]

On 12/11/2020 4:48 AM, Bob Eager wrote:
> On Fri, 11 Dec 2020 08:29:30 +0000, David Wade wrote:
>> Disabling "one or two" instructions would also be fairly pointless. Its
>> relativity simple to fix. When a "z" box (or any of its predecessors)
>> executes an undefined instruction a particular behaviours occurs and a
>> fault handler is loaded. The fault handler can then simulate the missing
>> instructions.
>>
>> This was used back in the day to simulate floating point or commercial
>> instructions that were options. It still works to this day.
> 
> The same was true on some British machines I have used. Lower end
> machines used software floating point (and other stuff) and higher end
> ones did it in hardware.
> 
> Such instructions were often known as 'extracodes'.

H-floating

:-)

Arne