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PUBLISHED IN LIMA NEWSLETTER
OCTOBER 1987
^^^^^^^^^^^^^^ HARDWARE FOR THE TI
^^^^^^^^^^^^^by J. Peter Hodie
(Ed. Note: The following article
is taken from the August 87 issue of
the Boston Computer Society TI User
Group Meeting Newsletter. It is the
best comparison of available TI99/4A
hardware I have seen to date. Most
of this hardware will be available
for sale at the upcoming Chicago TI
Fare. If you do get a chance to go
to the fair, BRING MONEY! You will
probably get a chance to actually see
everything that has ever been made
for the TI, software and hardware,
including the hardware described in
Hoodie's article. Often you can
purchase for less than advertised
prices.)
Rather than discuss the virtues
and pit falls of the 9640, this month
I am going to go over the details of
the standard hardware available to
99/4A owners. There seems to be a
great deal of confusion of the
capabilities of the various
peripheral cards, hopefully this will
clear some of that up (more likely it
will just make things worse).
DISK CONTROLLERS
There are 3 main controllers out
there, made by TI, CorComp, and
Myarc. They all vary in their
capabilities, so let me first list
the different features a disk
controllr can have. All disk
controllers can support double sided
disk drives. This means that if you
have drives that can store data on
both sides of the diskette, any of
these controllers is capable of
using that feature. Many disk drives
can support what is called "double
density." This is a method for
packing double the data onto a disk.
Most disk drives these days are 40
track, which is standard, while some
can support 80 track. 80 track means
that you can store twice the amount
of data as on a 40 track disk.
However 80 track drives usually
require more expensive diskettes
because the data is so compact on the
surface of the disk. Disk drives
vary in the time it takes them to
access data. The slowest speed is
about 20 milliseconds (ms). There
are drives that are as fast as 3 ms,
although these are more expensive.
The TI DISK CONTROLLER can handle
up to 3 double sided, single density,
40 track, 20 ms step time disk
drives. In otherwords, the TI disk
controler is the bottom of the line
in all respects. RYTE DATA currently
has availabble an EPROM set for the
TI disk controller that will allow it
to access 80 track drives, however I
do not know enough about the product
at this time to make any comments on
it.
The CORCOMP disk controller can
handle up to 4 double sided, double
density, 40 track, 20 ms to 6 ms step
time drives. This means that you can
have one more drive than the TI
controller, and each drive can hold
double the data. The drives can also
be accessed faster. The CORCOMP disk
controller has some nice extra
features including a good disk
manager (it was the basis for
DM1000), and a number of extra CALLs.
The disk controller literally takes
over the computer on power up,
however, which causes some
compatibility problems. This can be
fixed by purchasing a new EPROM set
from MG for about $35.
The MYARC disk controller can
handle up to 4 double sided, double
density, 40 or 80 track, 20 ms to 6
ms step time drives. This is
essentially the same capability as
the CorComp card. You can only use
80 tracks if you purchase a special
EPROM from MYARC for about $50 that
suppports 80 track drives. The MYARC
disk controller comes with probably
the best disk manager program for the
/4A, and has a built in CALL
DIRectory command to catalog disks
from BASIC and Extended BASIC. Also,
the MYARC disk controller is
noticably faster then the others
because of the approach MYARC took
in designing the card.
RS232 CARDS
There is very little to say in
this area. There are cards available
from TI (very rare these days),
CORCOMP and MYARC. They all have 2
RS232 ports (Ed. Note: You need a "Y"
cable to use both serial ports with
the TI card. I don't know if the
other cards need such a "Y" cable.)
and 1 parallel (PIO) port. The
CORCOMP will not work with the MYARC
print spooler (more below on that),
whereas the MYARC and TI will. The
MYARC suports some extra software
commands to allow for 19.2K baud (the
others stop at 9600, real slow
<grin>), inverted busy in software
rather than hardware, and some other
details. MYARC also has an EPROM
that will make the PIO port act like
the thermal printer (TP) if you need
something like that. However, really
all these cards are petty much the
same. Most people prefer the TI
card, and shun the CORCOMP. The
MYARC is probably the best and most
readily available these days.
MEMORY CARDS AND RAM DISKS
There are more memory cards out
there than almost anything else. TI
made a 32K memory card. That was it.
Most RAM disks, but not all, replace
this card. If you just want a 32K
card, they are available from MYARC
and CORCOMP and there is no
difference worth discussing between
these two cards. They both seem to
work reliably. (Ed. Note: Used TI
32K cards can often be obtained
cheaply these days as users upgrade
to MYARC or CORCOMP big-memory cards
and no longer have use for their old
TI card. Watch the newsletters for
ads.) Foundation made a 128K memory
card that replaced the 32K memory
expansion and gave you an extra 96K
of memory that could function as a
RAM disk. Unfortunately their RAM
disk software was terrible. Quality
99 software and others have since
released new software that makes this
card acceptable, however since it is
out of production it can't be
strongly recommended.
MYARC makes a memory card which
replaces the 32K memory card, and
comes with either 256K or 512K of
memory. The memory beyond the first
32K can be divided between a RAM disk
and a print spooler, although the
print spooler will not work with the
CorComp PIO port. For an aditional
$50 or so, you can get MYARC Extended
BASIC II, which is a much faster,
more powerful, and slightly buggier
version of Extended BASIC that will
work with the Foundation card or the
MYARC memory card. CORCOMP makes a
256K and 512K card, and these both
function as RAM disks. I don't know
much about these cards, except that
they are reported to work quite well,
so again I will make no comments.
The HORIZON RAM DISK comes either
as a kit or assembled, and provides a
very reliable 90K or 180K RAM disk.
It can also be upgraded to 256K. It
supports a very powerful operating
system including replacing the TI
title screen with a custom menu of
programs. The HORIZON RAM DISK does
not replace the 32K card and thus can
be used along with a MYARC or
Foundation RAM disk. (Ed. Note: If
you are NOT using the CorComp disk
controler it is possible to use as
many HORIZON RAM DISK cards as your
"P" box will hold, assigning each
card a separate drive number. As I
understand, it is only possible to
use one HORIZON card with a CorComp
controler. I have 3 180K cards in
my "P" box, giving me 540K of battery
backed up memory storage instantly
available every time I turn on the
computer. I don't have to use
floppy's very often since my most
used software is on the RAM disks.
Multiple HORIZON cards will work even
if you already have the maximum
number of floppy drives your
controler card is designed to handle.
With a TI card you can have 3 floppy
drives named DSK1-3 and additional
HORIZON RAM DISKS named DSK4-7.)
PRINT SPOOLERS
Your printer is much slower than
your computer. Your computer could
print a full TI writer document in a
few seconds. Your printer couldn't.
A print spooler is a device that
accepts your document as fast as the
computer can send it, and then the
spooler sends it to the printer,
while you can continue to use your
computer for other things. The first
print spooler was part of the
CORCOMP TRIPLE TECH card. It has 64K
of memory and ran independently of
the computer. The MYARC print
spooler is part of the MYARC 256K and
512K cards and can be anywhere from
1K to 400K. The MYARC print sppooler
is software driven, so that if your
computer fails while the spooler is
printing, your document probably
won't be finished. Further more,
some pprograms lock out the MYARC
print spooler so that it can't print
at all until you exit that program.
However, for most uses the MYARC
spooler is adequate.
There is another class of print
spoolers, which are separate hardware
devices that go outside your
expansion box. These will work with
any computer. They are usually 128K
of memory, and run about $90 or so.
These work quite well, and if you
don't want the added features of the
Triple Tech card (clock and speech
synthesizer in the box) or the power
of the MYARC memory cards, these are
a very economical solution.
SPEECH IN THE BOX
There are two ways to get the
speech synthesizer into your
expansion box. You can either get
th CORCOMP TRIPLE TECH CARD with its
print spooler and clock, or the RAVE
99 speech card. Both cards require
that you already have the speech
synthesizer as they both just provide
a connector for it. The TRIPLE TECH
CARD will not work with the 9640.
The RAVE card will, however it did
not work well with all speech
synthesizers, at last check. RAVE
has been good about trying to resolve
this problem, and since their card
is only about a third the cost of the
TRIPLE TECH card it does provide a
reasonable alternative. (Ed. Note: If
you are handy with a soldering iron
it is possible to put your speech
synthesizer permanantly inside your
99/4A console. Back issues of
Northwest 99er News and other
newsletters tell you how.)
CLOCKS
There are several clock cards
available, all radically different.
The MBP (MPB??) clock card is one of
the earliest, and works well. The
CORCOMP TRIPLE TECH clock is probably
the most popular, although CORCOMP
also makes a standalone clock for
those who don't want the entire
TRIPLE TECH card. John Clulow
recently designed a memory card that
you can build which includes a clock
similar to the MBP. The problem with
all these clocks is that there is
almost no software that supports
them. Bulletin board programs can
use them, but mostly you'll have to
write your own software to handle
these clocks. (Ed. Note: "Checkbook
Writer" by Mel Nomina has a provision
for using the TRIPLE TECH clock to
automatically date check records.
This public domain software can be
obtained free from the Lima (Ohio)
Area User Group by sending a disk and
return postage to P.O. Box 647,
Venedocia OH 45894.)
IBM STYLE KEYBOARDS
There are two sources for IBM
keyboard interfaces. The first is
from RAVE 99, and they are quite well
established now. They have suppport
for special Multiplan and TI-Writer
modes to minimize key strokes, and
installation is straightforward. The
second source is ML Systems. They
supply only a key board interface,
you supply the keyboard. The RAVE
folks will supply you with a
keyboard, if you wish. The ML
Systems supports keyboard macros,
where one keystroke can send up to 12
key strokes to the computer. This is
a powerful feature, however if you
wish to customize the macros you must
pay an additional $20. There have
been reports that the ML Systems
interface is less reliable than the
RAVE, however I suspect that this is
due to the keyboard being used and
not the interface. Because the ML
systems interface is considerably
less expensive than the RAVE, it
might be worth taking the chance.
The one thing I can't stand about the
ML Systems is that it uses the ESCape
key to repplace the function key on
the /4A, whereas the RAVE uses the
ALTernate key. The RAVE choice makes
much more sense, using the ESCappe
key is horribly awkward. Look at an
IBM keybboard sometime and you'll see
what I mean.