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         Volume 4 Number 1       48/39/38             January 1979

                     Newsletter of the SR-52 Users Club
                                published at
                           9459 Taylorsville Road
                              Dayton, OH 45424
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Off-the-Shelf Custom CROMs
     A number of companies have commissioned TI to produce CROMs to
their specifications, in some cases with the intent of marketing them
as part of special-purpose 59/PC packages for small business and pro-
fessional groups.  Although the vendors of such packages obviously
prefer to sell them in as comprehensive a configuration as they can,
including software support and hardware maintenance, they may be willing
in some cases to sell the modules separately to users who have their own
machines and who need no help either using the custom CROMs directly or
in writing RAM programs to call CROM routines.
     From what I've learned sofar from people who have bought custom
CROMs, code is apt to be protected (can't be downloaded), and a single
module could cost a second buyer $600 or so.  This, of course, includes
a share of the software engineering which goes into its design and
checkout, as well as TI's charges for emulator time (typically $2000)
and fabrication, and vendor profit.  This compares with going to TI
directly with your own programs, and paying $12,000 for 250 units,
$17,000 for 500, or $25,000 for 1000.
     Anyway, here are a few facts, figures and contacts for members who
may wish to take advantage of already-made custom CROMs.  I make no
representation whatsoever as to quality or utility, but merely pass
this information along, hoping it will be useful to some members.
     Reynolds & Reynolds, Dayton, OH 45401 (513) 226-0808 x539 is
marketing a 59/PC custom CROM package which they call the COMPEG 2001
microprocessor for payroll computations.  TI identifiers have been
covered over by R&R markings, and a colored keyboard overlay labels
special-use keys.  The system is designed to automate so-called pegboard
payroll accounting, with one mag card "... containing the entire payroll
history of one employee."  The total package costs $1300, plus $100 per
year Maintenance fee.
     Horizons Technology, 7830 Clairmont Mesa Blvd San Diego, CA 92111
(714) 292-8331 "... currently does custom programming for government
agencies.  We design and program custom CROMs, produce our own magne-
tic cards, and distribute comprehensive software documents.  Most of
our customers are given a large system that is cost-effective; small
individualized programming jobs would have to be assessed on a case by
case basis."
     Z-Comp Division of Davis-Gilbert Co, Inc #616 The Landmark Bldg
Alamo Plaza, San Antonio, TX 78205 (512) 227-7777 has a Texas-oriented
custom CROM covering consumer installment financing loan computations,
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  The SR-52 Users Club is a non-profit loosely organised group of TI PPC owners/users
  who wish to get more out of their machines by exchanging ideas.  Activity centers
  on a monthly newsletter, 52-NOTES edited and published by Richard C Vanderburgh
  in Dayton, Ohio.  The SR-52 Users Club is neither sponsored nor officially sanctioned
  by Texas Instruments, Inc.  Membership is open to any interested person:  $6.00
  ($10.00 US abroad) includes 6 issues of 52-NOTES; back issues start June 1976 @
  $1.00 each ($1.67 abroad).
aimed at banks as primary users.  Prices are $970 with 59/PC, $835 with
59 alone, $795 with 58/PC, $660 with 58 alone, and $575 for the CROM
only.  This company plans to have other modules made which would apply
specifically to other states.
     Other custom CROMs include:  Oil and gas drilling engineering
computations by IMCO Services Box 22605 Houston, TX 77027; and Ophthal-
mological computations by Sonometrics, Inc 16 W 61st St NY, NY 10021.
Members with additional information concerning either the availability
or quality of custom CROMs are invited to share same.

The Game of Life
     A decade or so ago, University of Cambridge (England) mathematician
John Horton Conway developed a solitaire game which he called LIFE,
having as its purpose the challenge to the player to accurately predict
successive changes to initial starting patterns resulting from the
application of a few simple rules, and to formulate behavioral hypo-
theses to support the predictions.  As originally conceived, LIFE also
challenges the player to avoid easy-to-make playboard mistakes!  The
latter can be, and has been eliminated by computer mechanization, giving
way to a new challenge:  Writing efficient programs to produce any
desired number of successive patterns from input initial patterns.  It
is this challenge which will be addresses in 52-NOTES.  Members wishing
to pursue the playing challenges are referred to Martin Gardner's Mathe-
matical games discussions, beginning with the October 1970 issue of
Scientific American.
     The programming requirement is to take an input 2-dimensional array
of elements (organisms) and produce successive new arrays, each derived
from its predecessor according to 3 rules:  1) An existing element sur-
vives it is has 2 or 3 neighbors, 2) A new element is created (born)
when an empty position has exactly 3 neighbors, and 3) An element van-
ishes (dies) when condition 1) is not met.  A neighbor is defined as an
existing element occupying any of 8 possible positions surrounding a
given position, and all changes are considered to occur simultaneously.
Conceptually, the 2-dimensional field is infinitely large, to allow
patterns to move/grow without restriction.  Practically, of course, a
physical board, or computer memory is of finite size, imposing an upper
limit on pattern movement or growth.
     A practical 59/PC limit would appear to be a 20 X 20 field, within
which a reasonable amount of movement/growth can be accommodated by
restricting input patterns to the center 10 X 10 positions.  Over the
past year or so, I've received 59/PC LIFE programs from Mike Brown (128),
Rusty Wright (581), Lou Cargile (625), Bill Skillman (710), and Maurice
Swinnen (779), the latter being a translation of a German version
appearing in Display (V4N1/2) written by a Peter Klinghardt, whose pro-
gram inspired Bill to write his.  Of these, I judge Bill's to be the
best, and his 13 Nov 78 version lists below.  Bill does some tricky
things, and it's a challenge just to figure out how his program works!
He chose the - to represent an empty position, the 0 (zero) for an
established organism, a Q for a new birth, and a blank to signify a
recent death.  While Bill's choices are good, they may not be the best
for all users, and members wishing to experiment with other characters
can do so by altering the numerals at steps 147-148, 159-160, and 162-
163, which as written produce the blank, 0, and Q respectively.  For
example writing 50 at steps 159-160, and 04 at steps 162-163 changes
the 0 to II and Q to I.

                              52-NOTES V4N1p2
TI-59/PC Program:  Life                        Bill Skillman (710)

User Instructions:  Key g.i where g is the generation number (0 or 1 if
just starting) and i is any desired identifier, press E.  Input the
starting pattern as keyed strings of zeros and ones, up to ten per line,
press R/S following each input, see next line number displayed.  Pro-
cessing begins automatically following input of the tenth line, or may
be initiated sooner by pressing A.  Successive generations are printed
indefinitely until stopped with R/S.  To prepare to continue a run from
one turn-on to another, push R/S immediately following the printing of
the next population sum (s   Σ), note the current step number, and
record banks 3 and 4.  At next turn-on, read the recorded card into
banks 3 and 4 (in addition to a program card into banks 1 and 2), and
press GTO 222 R/S, unless the last stopped step was between 216-220,
in which case press GTO 220 R/S

Program Listing:

000:  LC' = SUM55 LE' INV Int X 1 EE 10 = INV EE rtn LB' R56 LD INV EE
026:  Op*1 Op31 rtn LD' Op24 R*4 S59 0 S53 R54 ÷ 1 EE 5 = INV Int x:t
052:  0 INV x≥t 069 B' 1 EE 5 ± Prd54 Prd59 GTO 072 SBR086 3 x:t R54
076:  x≥t 341 B' 1 EE 4 GTO 347 R56 S08 5 S9 CP R54 Int X .1 Prd53 =
103:  D54 x=t 172 R59 Int X .1 = S59 INV Int INV x=t 124 INV Stflg2 NOP
127:  R54 INV Int x:t .3 x=t 154 INV Ifflg2 172 .4 x=t 159 60 SUM8 GTO
152:  172 INV Ifflg2 162 47 + 14 = SUM08 1 SUM53 Op20 .01 Prd8 Dsz9 093
181:  R8 SBR009 D rtn 221721 Op4 R2 Op6 Nop rtn CLR 77 Op04 0 S8 S9
212:  Exc0 Op6 Avd CP x=t R/S Op22 SBR188 20 S03 7 S05 9 S4 S06 11 S7
241:  CP SBR325 S54 x=t 262 ÷ 10 ÷ SUM54 1 EE 8 C' SUM54 SBR325 x=t 284
268:  S53 SUM55 X 10 ÷ SUM55 100 C' SUM54 4 S1 D' Exc58 OP35 S*5 Op25
296:  0 Exc55 S54 D' Op5 Exc57 S*5 Dsz3 241 0 Exc58 S48 0 Exc57 S49 GTO
323:  202 Op25 Op26 Op27 R*5 + R*6 + R*7 = rtn SBR086 1 EE 9 X R53 =
351:  rtn LE CMs S2 SBR188 2020202020 S56 20 S01 10 S07 11 - R7 = R/S
387:  . Prt ÷ 1 EE 5 X 3 = S*1 E' Exc*1 Int Op21 S*1 Op21 Dsz7 380 LA
414:  SBR446 10 S07 20 S06 4 S1 SBR463 SBR463 Op5 Dsz7 425 SBR446 GTO
444:  202 5 S05 4 S1 B' D D D Op5 Dsz5 456 rtn R*6 S54 2 S4 D' S*6
473:  Op26 rtn   Note:  Bill's program was written with Adv at step 200.

Also note that the . at step 387 is to clear a hardened display for
all-zero inputs.
     Members are invited to try to out-do Bill with better (faster, more
versatile, etc) LIFE programs.

More on Program Copyright (V3N5p4,5)
     Ken Widelitz explores the topic further (Kilobaud Jan 79 pp 9,10),
reviewing the National Commission on New Technological Uses of Copy-
righted Works (CONTU) final report, and its recommendations to Congress
for amendments to the Copyright Act of 1976.  While Widelitz states
that he agrees with the conclusions of the report, much of the text he
airs leaves me with the impression that for all of its attempted speci-
ficity, the CONTU report fails to provide an achievable means to define,
much less protect the rights of originators of computer readable works.
     My own feeling is that the only practical way to prevent program
plagiarism is to deny the type of access to the program that makes copy-
ing possible.  But that's easier said than done.  Users have already
succeeded in getting at and copying the 59 code on a "protected" card,
and I suppose there might be some effort being devoted to revealing
protected CROM code.  However, the CROMs present an interesting special
case:  Revelation of their code may actually enhance their marketability,

                              52-NOTES V4N1p3
since potential users would be able to verify what they're getting, and
could very well find that buying the CROM (TI or private custom off-
the-shelf) beats filling up RAM with plagiarized slower-executing code.
     Nevertheless, TI considers its CROMs to be copyrighted, even
though it doesn't publish listings.  The label on a CROM does indeed
contain the circled c and the year, but perhaps that could be construed
to apply only to the label itself.  The question of whether programs
cast in ROM are patentable or copyrightable appears not to have been
conclusively answered yet, since as Widelitz states:  "Some companies
have successfully patented computer programs by getting the patent on
'firmware'.  Since patent and copyright are mutually exclusive, it will
be interesting to see how this conflict is resolved."
     Fred Fish's User Survival Guide (V3N3p1) may turn out to be an
interesting test case, since it is copyrighted, and lists the ML CROM
programs.  Who knows, it might turn out that TI would be required to
obtain Fred's permission to publish its own listings!

Book Review:  Sourcebook for Programmable Calculators, TI Learning
Center, 1978, $12.95, 416 pages
     This TI publication was designed to provide the user of 58/59
machines with a wide variety of straight-forward applications programs,
each accompanied by a brief tutorial.  Topics span number theory,
algebra, trig, calculus, statistics, music, business, economics, bio-
logy, medicine, engineering, physics, and astronomy, with pedagogical
treatment generally as light as is possible for each subject.  No pro-
gramming experience is assumed, and program understandability appears
to have dominated over I/O and execution efficiency considerations
when the routines were designed.
     While there is no attempt to teach programming techniques, each
listing and corresponding user instructions include Purpose/Comments,
and Display/Comments, respectively, facilitating user comprehension.
Master Library routines are called when appropriate, but there are no
warnings to the user to assure ML module installation.
     I haven't yet checked out all the algorithms and routines, but
they appear to have the backing of a panel of college-level educators,
and I recommend this book to TI PPC users who need help getting started
at mechanizing algorithms on their machines, and to users of computing
machinery in general who are looking for brief introductions to the
covered topics.  Users are, of course, advised to be on the lookout for
errors.  For example, Jerry Johnston (493) spotted some questionable
code, and suggests that 2 STO instructions at locations 042 and 061
of the equation of Time Routine (page  11-39) should be deleted.  I
suspect that the STOs in question should be replaced by GTOs.

CROM RNG Limitations
     Don Huffman (902) has found that TI's random number generator used
in several of the CROMs doesn't always guarantee a period of m (199017,
as stated on page 54 of the ML Manual).  In fact, a bit of trial and
error turned up 2 unrelated 13-digit seeds which Don found produced
sequences with periods under 500, which means that a little search pro-
duced over 900 seeds which would initiate sequences of cycle length less
than 500.
     It turns out that with the linear congruential method, a minimum
cycle of length m is only guaranteed when the seed is an integer and
subsequent seeds are carried as exact reals (see Theorem A in Knuth's

                              52-NOTES V4N1p4
"The Art of Computer Programming" Vol 2 p 15, and Exercise 1 p 31).  But
it may be that TI's routine carries most successive reals to sufficient
precision to meet the exact reals requirement, provided the input seed
is an integer.  Has anyone found an integer seed which produces a cycle
shorter than m?

The PC-100C Printer
     TI is currently marketing domestically a printer labeled PC-100C,
which appears to be similar to the 100B (V3N9p6).  The 100C differs
from the 100A primarily by being adaptable only to the 58/59 machines,
having a non-detachable power cord, and allowing calculator operation
with PC power off.
     A 100C which I've tried is noisier than other PCs I've used, a
characteristic which may just be an isolated case.  Calculator operation
with PC power off is the same as when on, as far as PC connection sen-
sing is concerned (i.e. Ops 1-4 load print buffers, Op 7 on a display
greater than 19 causes an error condition, and Op 8 initiates a label
search to the end of the current partition (but without printing labels)).
The 3% execution slowdown (V3N7p6) appears to prevail with PC power
either on or off.
     Externally, the 100C looks about the same as the other PCs, but a
look at the inside, with the top removed, shows quite a few changes.
The PC board (here, PC means printed circuit, not print cradle!) shows
marked differences in circuitry and components.  What appear to be 2
high-power diodes are fastened to 2 much smaller heat sinks, eliminating
the 100A's one large one, and a single large capacitor has been replaced
by 2 smaller ones.  The print assembly appears to be about the same,
although the step-motor and transmission are different in appearance,
and made by a different manufacturer.  (Maybe this accounts for the
higher print-noise level).  Some components on the PC board nearest the
tape supply have been relocated, and a cardboard guard eliminated.
     Further comparisons among the various PC-100 models are invited
from the membership.

     Dave Leising (890) has found an ML-19 point (SBR 172) to execute
an effective Op*53, making it possible to have any of the 40 Op functions
executed in the CROM.  One that he found interesting with printer con-
nection is Op 8, which produces a somewhat odd mnemonicless listing of
RAM code.  To see what happens, at turn-on, key 10 Op 17 8 STO 53, write
some code at both ends of the partition, press (latch) the TRACE key,
and key Pgm 19 SBR 172.  The first 2 steps are printed as 000 01 and
001 00 followed by the "real" steps 001-158.  Step 159 is printed as a
code 43 (RCL), and execution halts following an effective Prt of the 8
in the display.  Inspection of the last step confirms the code 43, but
a look at step 000 shows a code 85 (+).  If during the listing the TRACE
key is unlatched, label-search appears to continue without further
printing (even labels are ignored).  If the TRACE key is again latched
before the search ends, printing resumes with the remaining steps.
     While the CROM Op*53 executing as Op 8 causes execution to halt at
the end of the label search, other Ops let the CROM code continue to
execute, resulting in error setting and endless looping, unless several
key registers have been appropriately initialized.  So be prepared to
key RST to halt execution, when necessary.  Members are invited to exam-
ine the behavior of other CROM-executed Ops, an to share their findings.

                              52-NOTES V4N1p5
Tips and Miscellany
     Printing 12 Places (58/59/PC):  Mike Brown (128) has discovered an
efficient way to get 12 of the 13 mantissa places printed.  He found
that in TRACE mode, a RCL Ind on a register whose contents is a 13-
place integer causes 12 of those places to be printed!  (albeit along
with a little garbage and an error condition).  Invoke the following
sequence by pressing A, with the desired number to be printed in the
display register:  000:  R/S LA Prt S00 1 EE 50 Prd0 CLR Stflg9 R*0
CLR RST and see the number as displayed printed, followed by a trace
or R*0, which includes the unscaled 12 MSDs of the input number.  The
1 EE 50 is to assure that the input number is an integer, and may be
replaced by a larger or smaller scaling factor, depending upon the
expected range of inputs.  The RST should be replaced by INV Stflg 9
rtn and the R/S at step 000 deleted, if this routine is to be subroutine
     Revealed ROM Constants (V3N12p5):  John VanWye (982) suggests that
the non-normalized constants which Bill Skillman associates with steps
384-447 are not scaled at all (the machine treats them as fixed rather
than floating point (V3N7p1,2)).  Thus each 8-step register actually
holds a 16-place number, with an implied decimal point between the 2
MSDs.  But it's not clear how many of the places were intended to be
good.  John finds ln 1.0001 at steps 424-431 good to al 16 places, but
π and π/2 at steps 496-503 and 488-495 respectively appear to be good
to only 13 places.
     Friendly competition (V3N12p6):  Maurice reports receiving a "3"
routine from Richard G Snow (brother of Robert G (212)) tying my 11-
step routine, but here's a 58/59 one from Jared Weinberger (221) which
is 2 steps shorter:  INV lnx INV lnx INV lnx yx lnx x2 = lnx lnx.
(recall that INV lnx counts as only one step).
     Bridge deal (V3N10p2):  Bill's program has generated at least 2
opposite reactions:  Jared considers it insufficiently random at the
end, while Lou finds it worthy of replacing his (V3N2p5).
     A CROM Identifier:  58/59 users generally working with 2 or more
CROMs may find it helpful to insert a CROM-identifying card in the mag/
plastic card display slot to remind them which module is in the machine,
especially when a CROM-dependent RAM program without a CROM test is run.
     Membership Address Changes:  100:  C & C of Denver Rm 285 5440
Roslyn St Denver, CO 80216; 372:  572 John Hancock St Orange Park, FL
32073; 606: 2325 N 87th Way Scottsdale, AZ 85251; 751: 500 Newport Ctr
Dr #455 Newport Bch, CA 92660; 786: 2416 K St NW #805 Washington DC
20032; 1056: Street address is 7722 (not 722).
     An INV HIR Application:  Maurice Swinnen (779) notes that although
prefixing a HIR operation with INV to change its function may seem to
offer no advantage to straight specification, it can save steps in some
cases.  For example, since INV HIR 31 is the same as HIR 51, and INV
HIR 41 is the same as HIR 61, in cases where all 4 register-arithmetic
operations are to be subroutine callable, HIR 31 rtn HIR 41 rtn HIR 51
rtn HIR 61 rtn reduces to INV HIR 31 rtn INV HIR 41 rtn, when absolute
subroutine addressing either includes or excludes an INV, as desired.
     Print Overlays (PC):  Roger Cowell (1010) notes that print patterns
can be enhanced by repeated transport of the same tape past the print-
heads.  Depending on the length of the tape to be reprinted, some manual
re-registration (alignment) may be required.

                              52-NOTES V4N1p6 (end)