*****    ***         *     *   ****   *****  *****   ***
         *       *   *        **    *  *    *    *    *      *   *
         *          *         * *   *  *    *    *    *      *
         ****      *    ****  *  *  *  *    *    *    ***     ***
             *    *           *   * *  *    *    *    *          *
             *   *            *    **  *    *    *    *      *   *
         ****    *****        *     *   ****     *    ******  ***

         Volume 2 Number 6        48/39                  June 1977

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

The New TI PPCs
      The speculation is over (for awhile) following TI's announcement
the last week in May of the New TI Programmable 57, 58, and 59 calcu-
lators.  The 57 looks like even tougher HP-25 competition than the
SR-56, with 10 labels and an $80 list price; the 58 and 59 are some-
thing else, packing some fascinating new features that it is hard to
believe can be squeezed into a slightly smaller package than the 52,
and at list prices of $125 and $300 respectively.  Both use the same
instruction set, accept 5000-step plug-in read-only-memory (ROM)
program modules, and plug into the PC-100A printer; the 58 has half
the 59's memory, and no card reader.  The discussion that follows
applies to the 59, but is generally applicable to the 58 except for
the differences, just noted.
     120 general purpose memory registers are partitionable between
data and program storage use:  1 data register is equivalent to 8 pro-
gram steps from a 0/960 data/program mix to 100/160 in partitionable
increments of 10 registers (11 possible configurations).  Once a parti-
tion has been established, boundaries cannot be crossed (as with the 52).
Partitioning/repartitioning can be done from the keyboard or under
program control, except when a protected (in the proprietary sense)
card has been read, in which case the user cannot get into LRN mode,
single step, or recall as data, or copy on to another card the program
memory contents.
     The 5000-step ROM modules (which TI calls CROM for Constant ROM)
are accessed by program number, and run by subroutine name for execu-
tion through the keyboard or under user-program control.  The Master
Library (which comes with each machine) holds 25 programs from a 52-
step D.MS add/subtract/scaling routine to an 898-step matrix determin-
ant/inverse/simultaneous equations leviathan that will handle up to a
9 X 9 matrix, or a system of 8 equations.  Once a CROM program has
been accessed from the keyboard, subsequent pressing of user-defined
keys (A-E') refer to the CROM program subroutines, but a CROM program
must be accessed each time a subroutine is to be called under user-
program control.  CROM programs may be down-loaded into user-program
memory for inspection and/or editing, and run as user programs, but
not the reverse.  Configuring new CROMS is an expensive manufacturing
process, and is not a practical user capability.
     One of the most powerful of the new features is a set of 40
Control Operations that enable the user to control the printer in a
variety of 64-character alphanumeric formats and list programs
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  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
  includes six future issues of 52-NOTES; back issues start June 1976 @ $1.00 each.
(including mnemonics), data, and labels; calculate a few special
statistical functions; control and announce partitioning; configure
error-state processing; and control increment/decrement of the first
ten data registers.  Control operations are executable manually and
under program (user or CROM) control.
     The 59's mag cards are slightly smaller than the 52's, and so
cannot be used interchangeably.  Each card reads/writes 2 of four
memory banks, irrespective of partitioning.  Each bank holds 30 data
registers or 240 program steps, or equivalent mixes of each.  Data
registers number from the last of bank 4 up through the last third of
bank 1 (2-digit addressing does not reach past Reg 99); program steps
start at the beginning of bank 1, with step 959 ending bank 4.  As
examples:  program steps 160-167 are equivalent to data register 99;
steps 472-479/Reg 60; and 952-959/Beg 00.  Partitioning is specified
by data registers.  For example, the sequence:  2 *Op 17 produces a
20/800 data/program-step mix.  But since program protection is by bank,
a bank that contains any/data registers cannot be protected, and steps
720-791 in this example could not be protected.
     The 59 keyboard is the 52's 5 X 9 matrix with some rearrangement,
renaming, and the following changes:  x!, D/R, iferr, ifpos, ifzro,
and xrty have been eliminated, and CP, Pgm, x:t, Eng, Int, abs, Pause,
x=t, Nop, Op, x≥t, sigma +, x bar, Rad, and Grad added.  Most key
codes follow the usual quasi-x,y addressing, with a few exceptions to
handle merged Ind functions.  8 of the possible 100 op-codes are unused,
and are the 59's pseudos.  Cursory investigation reveals that of the
8 (op-codes:  21, 26, 31, 41, 46, 51, 56, and 82), p82 is the most
interesting:  no matter what is displayed, it always causes the next
step to be skipped; if zero (or in some cases a small number) is
displayed, when the skipped step is R/S, Nop, or INVSBR (the 59's rtn),
execution of the p82 sets an error condition.  P21, p26, p31, and p41
(SST) appear to behave as they do for the 52.  So it seems that there
will be some challenge to exploring the 59's pseudos, if not so much as
for the 52.  Incidently, the 59's pseudos are easier to create because
of a register-address merging feature:  in LRN mode, any 2-digits
following a keyed register command (i.e. STO, RCL, etc) are merged into
a single step, and the STO, RCL, ... can be deleted later.  (You can
do the same thing with GTO).  But when you're editing a register seq-
uence you have to rewrite the command as well as the address.  For
example, if you wanted to change STO 73 to STO 74, starting at the step
containing tho 74 would produce the 2 steps: 07 04 instead of the
desired 74, so instead, beginning at the STO step:  STO 74 would give
you the desired sequence.
     Other non-52 or 56 features include:  6-level subroutine calls; 10
flags; indirect flag, Pgm, Op, fix addressing; Dsz of Reg 00-09; SBR n
from the keyboard initiates execution (true for the 57 also); 13-digit
display arithmetic; and a manually initiated R/S during program execu-
tion will not halt execution in the middle of connected sequences.
     On the negative side, varying in degree of severity and subjective
importance:  Only 8 mantissa digits are displayed when in Sci or Eng
format (like the HP-25), although 13 digits can be carried in the
display register unless EE is executed, in which case rounding is to 8
places; there is no built-in factorial function and although Pgm 16
(Combinations, permutations, factorials) will calculate a factorial, 3
subroutine calls are required, and Reg 01-04 are used; polar/rectangular
functions and character-print buffers use 4 stack registers; there is
no manual D/R switch or other equivalent to the 52's-interrupt process-

                              52-NOTES V2N6p2
ing capability; there is apparently no user access to the stack reg-
isters, and thus no fractured digits; the same 52/56 trig and log
function anomalies prevail (V1N2p3 and V2N2p1); the same code-transfer
rules apply (V1N2p2); there is no INV or Ind viability through sub-
routine calls; and a timing comparison of a short Dsz loop showed that
the 59 took twice as long as the 52 (varying display format appeared
to have ne effect).  This longer Dsz execution time is probably due
to the addressing of a particular register (which neither the 52 nor
56 have to do).
     The following features will probably be viewed by some users as
plus and by others as minus:  Program execution halts when an undefined
label is encountered; mag cards cannot be protected from accidental
over-write (although since read is automatic there should be little
need for the black tab type of protection); there appears to be no
special 0 divide error state (V1N1p2); and there are no "crashes"
except for the p21 sin sequence (see the pseudo table elsewhere in
this issue).
     One of the powerful features of the 59/PC-100A combination is that
they can be programmed to operate like an interactive computer terminal.
The following program illustrates this capability.  Press A, and you're
off on a graded course in arithmetic!

TI-59 Program:  Interactive Arithmetic Teacher                  Ed

Program Listing:

000:  *Lbl B STO 0 *Lbl E RCL*Ind 0 *Op 1 *Op 20 RCL*Ind 0 *Op 2 *Op 20
018:  RCL*Ind 0 *Op 3 *Op 20 RCL*Ind 0 *Op 4 *Op 20 *Op 5 INVSBR
033:  *Lbl C *CP *B' X RCL 79 = *Int *x=t C STO 75 *Lbl 3' *B' X RCL 79
052:  = *Int *x=t 3' x:t RCL 75 INVSBR *Lbl D *Pause x:t *Pause INVSBR
066:  *Lbl A 1 B E E E E E *Adv E *Adv *Lbl 9' 10 STO 79 0 STO 77 STO 78
089:  *Lbl 1' 29 B 0 R/S *CP *x=t 2' C + D STO 76 = x:t 47 *Op 4
110:  *Lbl 6' CLR R/S STO 74 *x=t 4' *A' 313237 *Op 4 x:t *Op 06 453241
136:  *Op 4 RCL 74 *Op 06 53 B *Adv GTO *1' *Lbl *2' E 0 R/S *CP *x=t
155:  *5' C + x:t = STO 75 - D STO 76 = x:t 20 *Op 4 GTO *6' *Lbl *5'
176:  E 0 R/S *CP *x=t *7' C X D STO 76 = x:t 50 *Op 4 GTO *6' *Lbl *7'
197:  E 0 R/S *CP *x=t *8' C X x:t = STO 75 div D STO 76 = x:t 72
217:  *Op 4 GT0* 6' *Lbl *8' *Adv 57 B 3221 *Op 4 *RCL 77 *Op 6 RCL 78
239:  *Prt E E 0 R/S *CP INV *x=t *9' E *Adv *Adv *Adv CLR R/S *Lbl *4'
256:  1 SUM 77 *A' 3632 *Op 4 x:t *Op 06 45 B E 0 R/S *CP *x=t *1' 10
280:  *Prd 79 GTO *1' *Lbl *A' 1 SUM 78 RCL 75 *Op 06 64 *Op 4 RCL 76
299:  *Op 6 INVSBR *Lbl *B' *pi x RCL 73 = INV *Int STO 73 INVSBR

Pre-stored Data:

01:  2324572465  3000223224 3122003732 37173637 4532413500  1335243723
07:  3017372415 0 1314242724 3745401331 3643173500 3441173620 3724323136
14:  2002132 3500451736 5700010000 2132350031 140273232 2600213235
20:  16243620 3327134520 3313413617 1600323317 3513311636 2617450013
26:  3136431735 5737231731 35413140 4313313700 3732001316 1671000000
32:  0 4313313700 3732003641 1437351315 3771000000 4313313700 3732003041
39:  2737243327 4571000000 4313313700 3732001624 4224161771 0 4532410043
46:  1735170035 2422233773 43133137 2313351617 3500333532 1427173036
52:  7100000000 1424351620 1435132431 1716001641 3115177300 4532413500
58:  3615323517 24360000 0 3335321427 1730364043 1331370037 3200373545
65:  2132350013 14173737 1735003615 3235177100 2313421700 1300312415
71:  1700161345 4014451740 .1415926536 0 0 0 0 0 0

                              52-NOTES V2N6p3
     While you probably won't be able to try out this program for awhile
(the first production 58/59 machines aren't expected to-be on retailers'
shelves until late June or early July), at least one retailer is selling
the owner's manual now (Lectro-Media Ltd Box 1770 Philadelphia, PA
19105 (800) 523-2906, for $12.95) ... a 250-page 8½ X 11 combination
programming guide and functional analysis which covers a lot of ground,
and can get you started writing programs and deciphering mine (and/or
improving it) while you're waiting to get a 58 or 59.
     Although 52-NOTES will be giving the new machines increasing cover-
age, some space will continue to be devoted to significant topics concern-
ing the old, depending upon member interest; important functional and
operational comparisons of one machine with another will be of general
interest for some time to come; then, ofcourse, the 58 and 59 will have
to wait for HP to catch up before they can fairly enter the Friendly
Competion arena!
                          - - - - - - - - - - -
Pseudo Behavior Summary (52)
     Herewith a quick reference for pseudos, which consolidates inputs
from many members;
     21:  A, E, F; causes crash* when followed by sin, cos, tan, P/R,
          or D.MS during program execution
     26:  A, B, D, F;
     31:  D; causes a halt in LRN mode during program execution
     61:  A, B, D;
     62:  B, C, D;
     63:  D; executes as iferr
     64:  D; executes as INV
     66:  A, B, D;
     71:  A, E; SST of the first of a string of n p71s causes a skip of
          n+1 steps
     72:  B, C, D; cannot be inversed
     73:  D; executes as rset
     74:  D; executes as GTO
     76:  A, B, D;
     82:  B, C, D; cannot be inversed
     83:  D; causes complex interaction among display, arithmetic stack,
          internal registers, and functional states
     84:  D; similar to p83
     92:  B, C, D;
A=conditionally neutral; B=can provide missing operand; C=executes as EE
and softens display selectively; D=may be used as a label; E=executes as
a no-operation; F=when SST'd, creates a pending shift;

*Machine displays the two minus signs, and will not respond to any
keyboard command except power off.

Hardware Modifications
     Bob Edelen (100), Michael Rak (502), and Tom Scogin (517) are
emerging as the Club's top hardware modification enthusiasts.  Both Bob
and Mike are starting chip add-on services, and expect to do other machine
mods for interested users.  I will publish the names of other Club mem-
bers wishing to announce services related to PPCs and their use, but in
no case should such announcements be construed as carrying Club affilia-
tion or endorsement.  Incidently, members who wrote to Mike (V2N5p3) may
wish to contact him again for more details; both he and Bob report special
mounting requirements for SR-52As.

                              52-NOTES V2N6p4
More on Corner the Lady (Wythoff's NIM)  (52)
     Michael Brown (128), Dix Fulton (83), and Larry Mayhew (145)
have written SR-52 programs for this game (V2N4p3), each taking a
different approach.  Michael's handles the largest playing field
(1D10 X 1D10) but follows a partially iterative algorithm that costs
execution time.  Dix's is limited to a 99 x 99 field and also requires
some trial-and-error search.  Larry devised a non-Fibonacci Notation
closed-form algorithm, and his program runs the fastest, handling a
playing field up to 99999 X 99999.  All three programs are well written,
and it would be difficult to decide which represents the best program-
ming, but I would judge Larry's to be the most playable.  Larry
modestly suggests that his algorithm is probably not as mathematically
elegant as the Fibonacci Notation one, but there is no denying the
proof of his pudding!  While 52-NOTES is not the appropriate forum to
pursue mathematical games in great detail, I will devote some future
space to this topic should member interest/effort be sufficient.  In
the meantime, interested members might wish to contact Mike, Dix or
Larry for further details of their programs.

A Few Tips on Presenting Your Inputs to 52-Notes
     It will be easier for me to use your inputs to 52-NOTES if 1)
separate topics are on separate pieces of paper, 2) little or no text
rewording is required, and 3) programs are typed following a modified
Dix Fulton format (V1N3p4), i.e. mnemonic strings with row-wise cate-
nation (filled lines), without omitting the * (for 2nd) symbol.
Incidently, although several have suggested the / symbol to denote
division, in certain contexts it might be misinterpreted as a delimiter,
and I prefer to stick with div.  Try to use mnemonics as close to key-
board inscriptions as can be typed, follow upper and- lower case conven-
tions, and run merged code together.  Note that for the new machines
(58 and 59), LBL is Lbl, and rtn is INVSBR.  I suggest that we adopt
the symbols:  abs for absolute value, S+ for sigma plus, and use 0', 1',
... 9' for labels, rather than the actual shift functions (Dsz, ifflg,
... Op) they represent.  I am now inclined to reverse an earlier posi-
tion (V1N1p5) and suggest that prograns submitted for 52-NOTES publica-
tion be in relocatable form to make them easier to modify for individual
preference (the SR-56 excepted).

SR-52 Program Review: Analytic Computer Model by Ron Zussman (88),
Computer Design, May 1977 pp105-109; reprints @$1.50 ea or entire
manuscript @$3.00 ea available from Ron.  As big and fast as modern
computer operating systems are, their limitations are finite, and
their efficiency depends in large part on how well hardware resources
have been configured to match specific job loadings.  Analytic models
have been devised to determine optimum mixes and arrangements of
computing machinery for predicted user traffic.  Ron's program mech-
anizes one of these, based on queuing theory.  From 7 inputs: 1) Time
the central processing unit(s) is (are) active (CPU(s)) for each job,
2) proportion of (1) used for I/O, 3) average service time for peri-
feral storage access, 4) total number of jobs, 5) number of system
users, 6) Average wait times (for interaction), and 7) the number of
CPUs, this program calculates CPU utilization, thruput, and response
time for both exponential and constant models.  Members applying this
program to real operating systems are invited to convey comments/
results to Ron and/or me.  Users should note that the user instructions
in the CD article incorrectly list results under a "Press" column (p107).
Corresponding keys may be found at the bottom of p 109.

                              52-NOTES V2N6p5
     A yx Workaround:  In cases where you want yx with x already
displayed, Roy Grubb (483) suggests:  X y lnx = INV lnx which takes
advantage of the mathematical identity:  log yx ≡ xlog y.
     A Decrement Only dsz (56):  Roy Chardon (515) notes that ... *dsz
CE ... decrements Reg 0 without causing an error condition (analogous
to the V2N2p1 sequence for the SR-52).
     0 divide Error State (56):  Roy also notes that several functions
are affected during a 0 div error state for the 56:  notably, the
statistical and rectangular/polar; also that PROD executes as INV
PROD (contrary to Dave Johnston's finding (V1N2p6)).

TI Notes
     The customer service toll-free number (V1N1p6) should be changed
to 800-858-1802;  use 8O6-747-3841 (not toll-free) for technical
     For those of you going to Dallas-for the NCC (13-16 June), TI
expects to have several applications people there to answer questions
concerning the new machines, and if they're not too swamped, you
might be able to get your hands on a 57, 58, or 59.  The Professional
Calculator Division is in the process of moving to Lubbock, so just
who will be where and when at the NCC can best be found out by contact-
ing TI at the Dallas Convention Center when you get there.
     TI is starting a separate program exghange for the 59 (PPX-59),
with its own newsletter and catalog.  More details as they become
available.  There are no plans to drop PPX-52.

Coping with Built-in Function Anomalies
     Since most built-in functions produce approximations to desired
results, and since the accuracy of the approximations is often depen-
dent upon the magnitude of inputs, it is not surprising that some data
regions cause problems.  Manufacturers are motivated to find a com-
promise between complicated algorithms that handle all cases with equal
accuracy and simple ones that break down significantly for specific
inputs.  It appears that HP considers it cost effective to spend more
for "cleaner" functions than TI does, although the best algorithms don't
necessarily cost the most to implement.  Seemingly unrelated machine
architecture features can affect the accuracy of results.  For example,
HP-machines do not flag underflow conditions, which makes it easier
to process data whose magnitude is close to zero.  Joel Pitcairn (514)
notes that knowledge of algorithm construction would enable users to
identify critical data regions, but unfortunately the manufacturers
consider such information to be proprietary.  A TI spokesman points
out that even publishing information identifying critical data regions
would give the competition useful ammunition.  So I suspect the best
approach is to find out as much as you can about the way a machine
processes problems of interest before you buy, and then for significant
programs, devise test procedures that cover all expected data ranges.
And then ofcourse, when in doubt, round!  For you mathematicians, Joel
and Barbara Osofsky (420) both note that lnx of numbers in the neigh-
borhood of 1.0000007 results in only 6-place accuracy.  Joel also
finds similar accuracy degradation for sin .00007 and tan 1.0000000002.
Incidently, the 58 and 59's built-in math functions appear to be the
same as for the 52 and 56.

                              52-NOTES V2N6p6 (end)