On Sun, 11 Apr 2010 00:26:41 -0500, Morris Dovey wrote:

On 4/10/2010 11:16 PM, Doug Winterburn wrote:

By "thin film", do you mean it also had the cros (capacitance read only
memory) instruction set as the 360/30? It was punch card size mylar
with copper traces that were punched out on one of four sides of a
square or some such. The first time I saw the 30 power on and the cros
"pump up" to push the cros punch card ros together, I wondered "WTF"?

You and nearly everyone else - I've always suspected it was designed by
the same madman who designed the 407...

I honestly don't know how RCA implemented the instruction set or the
internals of IPL. I suspect that they may have used ROMs, because IBM
was likely to have the CROS covered every which way with patents.

Thin film refers to (yet another) logic family (like ECL, TTL, MOS,
CMOS, etc). RCA claimed it was cheaper, provided higher yields, and was
more reliable. Of course, when you asked around you discovered that
every company's technology flavor was well above average.

"Thin film" was a manufacturing process rather than a logic family. IIRC,
everything was RTL at that time. IBM's variety was SLT (Solid Logic
Technology). It *was* RTL. ECL didn't come along until the 370s and "MST"
(Monolithic Solid Technology), which was made by TI.

You might get a kick out of learning that the floppy disk was originally
developed to load the microcode into the ill-fated object-based FS (for
Future System) machines.

Nah, floppies were used on the 370/158s to load microcode, well before FS.

Then there was the 360/40 with the "tros" micro programmed instruction
set...

That's the one I started with in '64.

I was away from computers from 62-65 working for Uncle Sam, but IIRC I
was introduced to the 40 (but it could have been a 50) and DEBE at the
same time.