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ORIGINALLY PUBLISHED IN LIMA NEWSLETTER APRIL 1993
NEVER RELEASED OFFICIAL TI PERIPHERALS:
THE HEXBUS INTERFACE; A KEY TO WHAT MIGHT HAVE BEEN
a hands on description by Charles Good
Lima Ohio User Group
The Hexbus Interface (PHP1300) allows you to control all the neat little
hexbus peripherals directly from the 99/4A console. With this interface and a
side car 32K (or 32K installed inside the console) you can create a fully
expanded system with a very small footprint (occupying little surface area).
If you paid full list 1983 TI prices, the cost of your expanded system would be
much less than an expanded system based on the peripheral expansion box.
If you have a box that contained a beige console you can see what a TI
Hexbus interface looks like. There is a picture of one on the bottom of the
box attached to the side of a console. TI listed this device in its last price
list (dated June 1, 1983) for $59.95, but it was never officially released.
Only a handful of original TI hexbus interfaces are known to exist. I have
such a 1983 TI hexbus interface on loan from Gary Taylor for this report, and I
now also have my very own BRAND NEW cloned hexbus interface. For years people
have been trying to clone TI's original interface and now it has been done. As
of right now I am one of two people to own one of these cloned interfaces.
More on this later.
Gary's official TI interface measures 8 x 3.5 x 2.25 inches. It connects
to the side o the console and has a connection on its right side for other
standard 99/4A peripherals or the peripheral expansion box cable. On the back
is an on/off switch, a power supply jack for the required model AC9201 6v 300ma
external power supply, and one hexbus connector. There is no serial number or
date code (ATA or LTA number) on Gary's interface, indicating that it is a
preproduction prototype. There is, however, an FCC identification number
(A929JWPHP1300), and a statement that the device has been approved by the FCC
for "class B" use in the home.
The following hexbus peripherals have been tested by me using a 99/4A
console and the hexbus interface with no problems. These are all very small
peripherals, and all of them except the RS232 can be run on batteries as well
as AC current. With the exception of the Printer 80 they all stack neatly on
top of each other. You can place the whole stack of peripherals on top of the
hexbus interface where it is connected to the side of the console. The entire
footprint of all these peripherals when stacked on top of the interface
OCCUPIES LESS TABLE SPACE than fire hose PE Box connector when connected to the
console. The PE Box connector sticks out frather from the right side of the
console than does the hexbus interface and stack of hex bus peripherals!
--Hexbus RS232 with parallel option: can be used to run any printer.
--Hexbus modem, doesn't require an RS232, 300 baud.
--Wafertape drive. This is a "never released peripheral" that I own. Up to
8 of these can be cabled together in a single system.
--Hexbus 4 color printer/plotter. This tiny printer can be addressed
directly and does not need an RS232.
--The Hexbus "Printer 80" 80 column thermal printer also works flawlessly
with the hexbus interface, but you can't stack it with the other peripherals.
Like the printer/plotter, the Printer 80 can be addressed directly and doesn't
require an RS232 interface. It uses fax paper or plain paper and a thermal
ribbon cartridge.
TI was developing a hexbus 5.25 inch floppy drive controller. I know of
two working examples of this controller in private hands, and one of these has
been tested successfully with a 99/4A hexbus interface.
Unfortunately, the Hexbus interface does not work properly with the
Mechatronic quickdisk drive, the one that uses 2.8 inch disks. You can save
programs to quickdisk, but you can't load them back off the disk into the
99/4A.
WHAT YOU CAN DO WITH THE HEXBUS INTERFACE:
According to TI's documentation that comes with the TI interface, the
device can be addressed in TI BASIC, TI EXTENDED BASIC, Assembly language, and
from the P-code peripheral. The usual syntax is
"HEXBUS.DEVICE_NUMBER.FILE_NAME". For example, to save a BASIC program to a
wafertape set up as device 2 (wafertape drives can be designated any number
from 1-8) you would type SAVE HEXBUS.2.PROGRAM and press <enter>. To list a
basic program to a printer attached to the hexbus RS232 you would enter LIST
"HEXBUS.50." where device 50 is the parallel output of the RS232. To list a
program to the printer plotter the syntax is LIST "HEXBUS.10."
I have used the interface with WORDWRITER, a cartridge version of TI
Writer. LF and then the file name HEXBUS.2.TEXTFILE will load TEXTFILE into
the edit buffer from wafertape device 2. PF and then HEXBUS.16. will print the
file directly to the Printer 80 (which is device 16).
The TI Hexbus Interface user guide was never officially published. It
would have been designated as document 1049000-1, and was last revised sometime
after March 1, 1983. (I have the March 1 revision. Errors in this revision
have been corrected in my copy of 104900-1.) This user guide suggests that you
can get a CC40 and 99/4A to talk to each other over the hexbus interface,
allowing the CC40 to store data on the 99/4A's drives and display information
on the 99/4A monitor. There is only limited truth to this. The documentation
includes a skeleton 99/4A BASIC program that is supposed to put the /4A in
"slave mode" so that it and its peripherals can can be controlled by a CC40
connected to the hexbus interface. The key word here is "skeleton". Big parts
are left out of this BASIC program, and nobody that I know who has a TI hexbus
interface can make this program work. Nobody has been able to SAVE or OLD a
CC40 program onto a 99/4A floppy drive or display CC40 text via a 99/4A onto a
monitor. You are supposed to be able to do this, but nobody can figure our
how.
You can use a CC40 (or TI74) to save data to a data file on wafertape and
then use the 99/4A to open the file and read the data into the 99/4A.
Wafertape drives are rare and not very reliable. It is really too bad that you
can't use the Mechatronic quickdisk drive with the hexbus interface.
THE KEY TO WHAT MIGHT HAVE BEEN:
Back in 1983 the hexbus interface would have been the key to a low cost
compact expanded 99/4A system. Lets compare costs, based on the rediculus full
list prices from TI's last official price list.
EXPANSION VIA THE PE BOX:
--PHP1200 Peripheral Expansion box...........$249.95
--PHP1220 RS232 Card.........................$174.95
--PHP1240 Disk Controller Card...............$249.95
--PHP1250 Floppy drive for PE box............$399.95
--PHP1260 32K card...........................$299.95
--PHP1800 Telephone coupler (modem)..........$199.95
----------------------TOTAL EXPANSION COST..$1574.70
EXPANSION WITH HEXBUS PERIPHERALS:
--You need a side car 32K and there is no such hexbus product. Doryt
Systems advertises one in the June 1983 99er......$175.00
--PHP1300^Hexbus Interface...................$ 59.95
--HX2000^^Wafertape Drive....................$139.95
--HX3000P^RS232 with parallel interface.....$124.95
--HX3100^^Hexbus modem.......................$ 99.95
----------------------TOTAL EXPANSION COST...$599.80
This would leave you with enough extra money to purchase additional hexbus
peripherals such as
--Additional wafertape drives. Up to 8 drives can be cabled together in
one system and you don't need any kind of "controller" interface.
--HX1000 4 color printer/plotter.............$199.95
--HX1010 Printer 80, released in 1984 at.....$249.95 (the TI impact
printer listed in 1983 for $750.)
So after listing it in their official price list, obtaining FCC
certification, and providing a color picture of the thing on each beige console
box, why didn't TI offer the Hexbus Interface to 99/4A users? I suspect the
answer is the failure of the wafertape drive to live up to expectations. My
wafertape drive, and those owned by a few other lucky collectors, are not very
reliable, particularly when operated on battery power. The key to system
expansion is reliable mass storage that is better than a cassette tape
recorder. Failure of the wafertape drive left the hexbus in 1983 with no mass
storage peripheral. But this may soon change!
.CE 3
NEW 1993 HEXBUS PERIPHERALS:
reported by Charles Good
Lima Ohio User Group
A hobbyist in Germany named Michael Becker is making clones of TI's never
released Hexbus peripherals in limited quantities. (Michael Becker also makes
a quad density disk controller and a "speech in the PE box" card that includes
TEII speech in ROM usable from extended basic without occupying normal XB
program memory space. This card was shown at the Feb 1993 Fest West.)
--99/4A hexbus interface. I own one of these clones. It is built like a
tank in a solid metal enclosure resembling the enclosure of the Mechatronic 80
column peripheral. Like the original TI product, the clone plugs into the
side of the console and has a connector for the PE Box cable. Unlike the TI
original my clone has an LED which flickers to tell me that my interface is
funtioning, and it does not require a spearate power supply.
--5.25 inch DSDD hexbus disk controller. This can be used for mass
storage with the CC40, TI74, 99/2, 99/8, and with the hexbus interface can also
be used with the 99/4A. Michael Becker has a TI original (a very very rare
device, even rarer than a wafertape drive) and has dumped all the code in the
PAL chips so that he can produce duplicates. I expect delivery of my
controller in a few months.
--Hexbus Video interface. This allows the CC40 and TI74 to display text
in 40 columns on a composite color monitor. One of my correspondants has seen
Michael's working prototype. It is better than the TI original in that it
will display in 16 colors, not just in black and white.
Another hobbyist, Lee Bendick, has cloned the CC40 EA cartridge and is
making this cartridge available to interested CC40 owners. This allows users
to program the CC40 in assembly language, storing assembly routines in battery
backed RAM cartridges or in the RAM of the CC40. I know of only 4 TI original
CC40 EA cartridges. I own one of Lee's cloned EA cartridges and it works as
described in my two massive CC40 assembly language manuals. You need either
a 5.25 hexbus disk drive or a wafertape drive to make the EA cartridge work.
Anyone interested in any of these CC40/Hexbus peripherals can write me at
P.O. Box 647, Venedocia OH 45894. I will put you in touch with Michael Becker
or Lee Bendick.
.PL 1