27 May
2014
27 May
'14
1:15 p.m.
-----Oorspronkelijk bericht-----
From: Tony Duell
Sent: Tuesday, May 27, 2014 8:08 PM
To: cctalk at classiccmp.org
Subject: Re: Catch and Halt Fire - Drama set in early days of personal
computing
Halt and Catch Fire is not a real computer instruction
that caused a race
condition that made the computer stop working. I imagine a bunch of
teenagers are scouring Intel technical manuals looking for the Code 2 Duo
equivalent of HCF.
I thought there was at least one microprocessor (Motorola 6800?) where an
undocumented instruction would cause the processor to simply do memory
cycles at the fasted posible rate, address incrementing each time, and
the procesosr ignored all inputs apart from reset.
While the machine did not catch fire, the system was essentailly locked
up until the hardware reset.
-tony
As usual, Tony is correct.
I remember that the 6800 has an undocumented (illegal) opcode
that did cycle through all addresses at clock speed. IIRC, it was also
mentioned in a BYTE article (when BYTE was still a joy to read).
- Henk