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Text File | 2006-10-19 | 13KB | 360 lines

 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.