ORIGINALLY PUBLISHED IN LIMA NEWSLETTER JANUARY 1991
 
^^^^ THE ORIGINAL TI HOME COMPUTER SYSTEM  
^^^^^^antiques decribed by Charles Good  
^^^^^^^^^^^^Lima Ohio User Group 
 
The "original" TI Home Computer system, released to the
public in 1979 and 1980, consisted of the 99/4 computer
(without the "A") and a series of stand alone peripherals
that plug directly into the side of the 99/4 (or 99/4A)
console, or into the side of the previous peripheral (hence
the unoffical descriptive term "freight train peripheral").
Each of these freight train peripherals except the speech
synthesizer has a base that measures 17x26cm (a bit larger
than 6.5x10 inches), a separate power supply rated at 0.2A
(23 watts) at 115 volts, and its own separate power cord.  I
recently purchased a "4" (just to play with) and was later
given many of the freight train peripherals.  After using
these devices for awhile I realize how fortunate we are to
have the "4A"and its peripheral expansion box.  
 
Components of the "original" TI home computer system are
listed below, together with their official TI part numbers
and some prices mostly quoted from an ad by CBM INC of
Lexington KY published on page 12 of the first edition
(May/June 1981) of 99er Magazine.  These CBM INC prices are
probably below TI's official list price.  These peripherals
are not the same as those designed to fit in the PE Box.  PE
box peripherals all have "PHA12xx" part numbers and are
described in official TI publications as "cards". 
--TI 99/4 console, (PHC004C): $499 
--RF (TV) modulator; in 1980 this was an extra cost item,
(PHA2100): $41 
--Solid State Speech Synthesizer; the same one most of us
still use, (PHP1500): $122  
--32K RAM memory expanion, (PHP2200): $325 
--RS232 Acessories Peripheral, (PHP1700): $183  
--Solid State Thermal Printer, (PHP1900): $325 
--Disk Drive Controller, (PHP1800): $243 
--Disk Memory Drive, (PHP1850): $399 
--P Code Peripheral, (PHP 2400): $399.95 
--Video Controller, (PHP2300): $699.95 
Prices of the last two items are official list prices quoted
from TI's suggested retail price list dated June - December
1982 (1049705-1). 
 
You can connect a maximum of three periphrals in series to
the right side of the computer.  If present, the speech
synthesizer has to be first and the 32K second.  A "typical"
freight train minimum expansion system (99/4 with modulator,
32K, thermal printer, controller and one drive) would be
almost four feet wide and cost $1832.  Bringing the system
up to the maximum of three SSSD drives and buying all the
other freight train peripherals would bring the cost up to a
total of $4035.  Wow! And you can only have simultaneous use
of 3 peripherals. 
 
In this article I will describe what I know about these
freight train peripherals.  I have hands on experience with
the Thermal Printer, 32K, and Disk Controller.  I will not
discuss the Speech Synthesizer since the 1979/80 device is
the same one we are all familiar with.  In a separate
article I will describe my experiences with the 99/4. 
 
--32K EXPANSION MEMORY: This functions exactly like the
equivalent PE box card.  These days you can, for about $10,
buy a 32K RAM chip that measures about 1x3cm and draws very
little current.  It amazes me that TI's original 32K was so
bulky and required a 23 watt power supply.  A 12 inch black
and white TV only draws 29 watts.  But I guess if you
compare a 1955 room sized UNIVAC computer in memory, watts
of power consumption, and bulk, the vintage 1979 TI 32K
looks pretty good. 
 
--RS232: This stand alone box offeres only one RS232 port
and no parallel port.  The PE Box RS232 card allows
connection of TWO RS232 (serial) devices (with a special Y
cable) AND one paralle device all to the same card.  The PE
Box card is obviously superior to the stand alone
peripheral. 
 
--DISK DRIVE CONTROLLER: This device used the original DISK
MANAGER module (the DMI), and can control up to three SSSD
stand alone drives.  Double sided is not available with the
freight train disk controller.  The main difference between
the DMI and DMII modules is that the "I" has no provision
for double sided disk initialization.  A TI stand alone
drive plugs directly into the back of the freight train Disk
Controller without the need for any special adapter cable
other than the cable that comes with the stand alone drive.
Other drives plug into the cable of DSK1 using a small
adapter board.  A special cable that comes with the PE box
controller card is needed to plug a stand alone TI drive to
the back of the controller card for use as DSK2 or DSK3.  An
interesting feature of the freight train controller in
combination with the DMI module is that they do not
recognize the "whole disk protected" byte >10 of sector
zero.  With the TI PE box controller and the DMII module, if
this byte is set for a value of >50 you cannot copy the disk
with the DMII. 
 
--THERMAL PRINTER: This is printer device "TP", and was sold
to TI users at a time when cheap dot matrix or daisy wheel
printers cost $600+.  The 1982 list price for the 99/4A's
official dot matrix printer was $750.  The TP uses 3.5 inch
thermal paper, prints 32 characters per line, and like all
thermal printers is both quiet and slow.  3.5 inch thermal
paper rolls are a non standard size these days.  TP users
either have to purchase 10 year old official TI paper from
one of the few TI dealers that stock this item, or use a
paper cutter to trim 8.5 inch FAX paper rolls down to 3.5
inches.  Such 8.5 inch wide FAX rolls are commonly available
these days from many stores including SEARS, KMART, and
WALMART.  On the title page of the TP manual it says that
the TP "prints a copy of a TI BASIC program or the screen
displays from certain Command Modules." And that is about
it! A few modules, such as MUSIC MAKER, allow screen dumps
with the TP.  You can specify output to the TP with the DMI,
DMII, PRK, Statistics, LOGO2, and maybe a few other modules.
You can't use the TP with TI Writer, Funnelweb, the EA
module, or Microsoft Multiplan.  From BASIC you can LIST a
program to the TP, a common application.  You can also OPEN
a file to the TP using any of these file attributes:
SEQUENTIAL or RELATIVE, DISPLAY or INTERNAL, OUTPUT or
APPEND, FIXED or VARIABLE.  I can't immagine what use
RELATIVE, INTERNAL, or APPEND have in OPENing a printer
file.  When opened in INTERNAL, the printer prints a
meaningless graphic of the internal representation of each
ASCII character.  The maximum length of a VARIABLE TP
attribute is 32.  All printed characters of the TP's built
in character set are on a 5x7 dot grid.  The TP has a unique
graphic set for ASCII 0-31 and the usual alpha/numeric
characters for ASCII 32-127.  Each printed dot of a
character is printed only once and individual dots can be
seen with the naked eye.  There is no way to make extra
dense high quality characters.  Emphasized, double strike,
and "NLQ" is not available.  The user can also, using an 8x8
dot grid, redefine ASCII chars 32-159 in BASIC using CALL
CHAR, and then directly print any of these redefined chars
to the TP with the appropriate keyboard keypress as in
PRINT^#1:"{" where { has been redefined, or with
PRINT^#1:CHR$(xxx).  This is a neat trick!^^It is much
harder to print redefined characters with other kinds of dot
matrix printers. 
 
--VIDEO CONTROLLER: A photograph and brief description of
this peripheral appears as part of an article on page 53 of
Volume 1, No. 4 of 99er Magazine (Nov/Dec 1981).  The
photograph shows a box identical to that of the stand alone
32K or disk controller, with a cable coming out of the right
side where the "pass through" expansion bus is found on
other stand alone peripherals.  The article describes the
video controller as allowing "computer controlled
interactive video with VCR's and Video Disk Players",
whatever that means.  As evidenced by the videos we created
from the formal preentations at the 1990 Lima MUG
Conference, it is possible without this device to mix human
voice, computer audio and video outout, and video camera
footage on the same video tape.  Such mixing of various
audio and video sources was done by us manually however, not
under computer control.  An extra cost cable ($99.95 for
each of the three available cables in the June - December
1982 TI price list) is needed to interface the video
controller to a Sony or Panasonic VCR or a Pioneer video
disk player.  I really don't understand the need for
computer control of a video disk player.  If I remember
correctly, 1980 video disks resembled phonograph records in
that you could only PLAY them from the beginning, not
record onto them. 
 
--P CODE PERIPHERAL: My June - December 1982 TI price list
states that this device is "available only until replaced by
peripheral card", with such a card "available in second
quarter 1982." The freight train P Code peripheral is
apparently exactly equivalent to the PE Box P Code card. 
 
There you have it folks, the original TI Home Computer
expansion "system".  Now you know why the expansion port on
the 99/4 and 99/4A is on the SIDE of the console, rather
than on the back where it should have been placed.  You can
only use three of these freight train peripherals at once,
and they take up huge amounts of desktop space.  Arn't you
glad we now have the PE Box! 
 
I want to acknowledge the generous gift of Mr.  E.T. Breer
of the St. Louis Missouri User Group who gave me several of
the freight train peripherals described in this review. 
.PL 1