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(SR-52) Queuing Analysis
01-25-2021, 11:51 AM
Post: #1
(SR-52) Queuing Analysis
An excerpt from Computer Queuing Analysis On a Handheld Calculator, Computer Design, vol.16 nº11, NOV 1977, pgs. 85-94

" Queuing theory can be practically applied to estimating computer performance and locating system bottlenecks. This is demonstrated by a generalized multiserver queuing model coded to run on the Texas Instruments SR-52 handheld calculator. The model is interactive so that effects of prospective design changes can be evaluated immediately, allowing an analyst to make the iterative design decisions required to optimize system effectiveness. Having the model preprogrammed for a portable calculator further increases its availability and convenience.
  Where a complicated problem can be separated into a number of basic queuing situations, it is often possible to use this calculator model instead of an extensive and expensive real simulation. Although the discussion concentrates upon computer central site queuing, this model also has wide application in communication systems and industrial engineering.

The Model
Challenges encountered in programming this model for the SR-52 calculator included the problems of trying to fit the code within 224 instruction steps, minimize calculator execution time, and provide convenient user operation. The resultant program, listed in Tables 1 and 2, is an optimal tradeoff between these three sometimes conflicting objectives.
  Subroutines were used extensively to enable the code to fit into 224 program steps. However, as subroutines take more time to execute than inline code, they were avoided in iterative loops. To further speed execution, frequently used labels were placed in low address locations and absolute addressing was used wherever possible.
  Ten user-defined functions can he executed by pressing the top row of keys on the SR-52 calculator. To provide maximum user convenience, these user-function keys are named and referenced … "

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SlideRule
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01-25-2021, 02:21 PM
Post: #2
RE: (SR-52) Queuing Analysis
Nice find!

In a past life, I taught Queuing Theory in management science classes. The students always HATED the equations and since the calculation of P(0) was so complicated in the multi-server situation, the book had a table to estimate it... and they still hated it.

There is a queuing theory program for the HP-41 in the pages of the PPC Journal circa 1983 or so. Angel put it into one of his test statistics roms for the DM-41X / HP-41CL / HP-41 emulator usage. Works great.

At HHC 2016 (?) I gave a short talk titled "Don't make me wait!" which discussed waiting lines. It is available on hpcalc.org's Youtube channel if anyone is interested.
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01-25-2021, 07:05 PM
Post: #3
RE: (SR-52) Queuing Analysis
(01-25-2021 02:21 PM)Gene Wrote:  ...

There is a queuing theory program for the HP-41 in the pages of the PPC Journal circa 1983 or so.
...

FYI, PPC Calc Journal V9N4P85 (from 1982) has the 10-page (!!) "HP-41 Queue" by Lauren Hansman (8587); followed by his posted list of corrections in V9N6P3.

Jake
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01-25-2021, 07:56 PM
Post: #4
RE: (SR-52) Queuing Analysis
(01-25-2021 02:21 PM)Gene Wrote:  At HHC 2016 (?) I gave a short talk titled "Don't make me wait!" which discussed waiting lines. It is available on hpcalc.org's Youtube channel if anyone is interested.

It was at the HHC 2017. Here is a link to the You Tube Video.
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