19 Jan
2005
19 Jan
'05
10:37 a.m.
Sellam wrote:
So, Geoff thinks this is an 11/33. I've never
even heard of an 11/33.
But there you have it. I've done my part.
It's an 11/53. That's the low end of the J11-based Qbus PDP-11 product
line. Though it's still significantly faster than an 11/23 (F11 chipset).
The J11 chip has capabilities roughly comparable to a PDP-11/70, the
biggest and most powerful TTL-based PDP-11 CPU that shipped as a product.
The J11 has microcoded floating point, but can optionally use a separate
floating point coprocessor chip; I'm not sure whether the 11/53 can
accomodate that chip.
Qbus J11 systems included the 11/53, 11/73, 11/83, and 11/93. The
main differences are the cache size (or absence), the clock frequency,
support for the floating-point coprocessor chip, and the amount of
main memory present on the CPU board (none for the 11/73 and 11/83).
The J11 was also used in the 11/84 and 11/94 Unibus systems, which are
the Unibs equivalents of the 11/83 and 11/93.
The J11 was used in the Pro 380 personal computer, and was used as an
embedded processor in many DEC devices, including the HSC60, HSC90, and
HSC95 storage controllers.
Eric