5 Sep
2007
5 Sep
'07
8:02 a.m.
On 5 Sep 2007 at 7:39, Lawrence Wilkinson wrote:
Totally unrelated to the topic at hand, but see
http://www.ljw.me.uk/ibm360/photos/ for an example of a "CCROS" card.
There was a book in the 60's about user microprogramming various
S/360 mainframes and their cousins. IIRC, the 360/30 was a great
candidate because of the easily-created ROS. The Model 40 wasn't as
good a candidate because it used magnetic technology (core of some
kind?) ROS.
The Spectra 70 was another great candidate for user microprogramming,
but I don't recall the technology used for the microprogram memeory.
The CDC Star-1B used "paper' ROS for its microcode. IIRC, crashes
because of errors were very common.
Cheers,
Chuck