Anyone running RTE-M on an HP 21MX series M, E, or F?

J. David Bryan jdbryan at
Thu Mar 11 21:47:03 CST 2010

On Wednesday, March 10, 2010 at 9:28, dwight elvey wrote:

> I don't have a 12821, it is a 59310. It should work for most any HP-IB
> thought.

One difference is that the 59310 is about 1/2 as fast: 470 KB/sec with 
standard memory and 570 KB/sec with high-performance memory.  The 12821 is 
buffered, so DCPC can steal every I/O cycle vs. every other I/O cycle for 
the 59310.  Speed is 937 KB/sec.  (Source: HP 1000/9000 Interface Products 
Specification Guide, 5954-6312, August 1985.)

I suspect that if an unbuffered drive is used with the 59310, overrun 
errors would occur.  If they didn't, performance may be terrible, as you 
might incur a one-rotation latency for each sector, unless the drive format 
was interleaved.

The 12821 was the interface supported for hard drive connections under RTE; 
the 59310 was positioned as an instrumentation controller.

                                      -- Dave

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