Dedicated to99/4A and 9900 Computer Systems
BOX 210 MOUNTAIN STREET
HALI BURTON, ONTARIO K0M ISO
/V U LUI II
V ITIk HZ
U I II HO
Where to start. This past month h
brought in a series of projects and
sources of information. This is 32k
month... Continuing with some of the
themes from past issues is a bit
difficult due to the VERY interesting
ideas coming in. We'll elaborate on
this later down the line.
First shot: Randy Holcomb of Computer
Shopper fame announced the M 32/16" » a
new memory expansion board for the
99/4A. This is a 32k memory 'card'
which fits INSIDE the console for
portable usage or general expansion ie:
running Logo II etc. with cassette only
(no boxes hanging off the side port.)
Randy explained that this new type of
expansion works off the 16 BIT BUSS
8b it multiplexed
lines DIRECTLY from
rather than the
approach used by TI.
board uses the 16bit
the 9900 CPU chip.
This gives you memory access speeds 20 -
50% FASTER than the normal 4A response
time. The wait state generator is
bypassed completely. COne of the
reasons the 4A can be so slow running
under Basic is that it 'waits' between
instructions to accomodate slow
memories. Today you can get 150ns chips
which can run with no wait states. 3 This
will make various applications which use
the 32k memory run faster - increasing
the power of the already considerable
computing ability of the 4A.
This board uses 8k x 8 CMOS memory chips
and installs inside your console above
the 9900 CPU socket . With each
expansion board you get a new 9900 chip
which plugs into the system in place of
your old CPU. Some additional features
are being explored for possible
inclusion at a later date.
Drawbacks? Well, this approach gives one
speed and portability (etc.) but it will
not allow the use of 128k cards. For
the majority of owners this is not a
"problem" or a drawback at all... for
me, I will do this to a new console as
the others use 128k cards of both
descriptions. As this board does not
make use of the MEmory ENable line, it
does not "see" any other banks of
memory. Apparently you can even have an
old 32k card in your system and it won ' t
collide' with this faster 32k design!
The 32/16 memory expansion board is
available NOW, fully tested (24hr.
burn- in is performed on each board) and
installed for *125.00 US funds.
Installation, parts etc. are fully
guaranteed. Top Radio, in doing the
installation, will also alter the power
supply to run cooler and insure
sufficient power in your console AND
install a MOLEX connector to ease any
future changes/ repai rs .
The board is also available as a kit
with parts for *75.00 US. You must do
the assembly and installation inside
your console. The guarantee is reduced
to 30days for kit builders.
For information and orders contact:
TOP RADIO SUPPLY
1785 Mt. Elliot, Detroit, Ml 4821^ or
call (313) 366-9088
As of this writing the kit or factory
installation cannot be reported on
fully. A kit will be obtained for a
ehensive report next issue.
ANNOUNCEMENT: DUE TO THE SUPPORT AND
ENCOURAGEMENT RECEIVED, R/D COMPUTING IS
COMMITTING TO A YEARLY FORMAT. We feel
that our favourite orphan really
deserves a technical upgrade - third
party i nnovat ion forum . Subscriptions
are the sole means of support for this
effort. For the time being product
advertising is not carried - which can
offset publishing costs. Please do
inform other TI owners who may be
interested! We would like to see the
newsletter grow into a major force for
the 3.5 million TI owners all over.
Currently issues are mailed to several
countries and numerous users groups.
The vision is to "cross polinate" all
the ideas from users and third party
innovators, give TI owners better
technical knowledge as well as providing
certain product input. A technical
library is being established to
distribute information, schematics,
hardware designs & tips to TI users.
Articles, designs, software, ideas, wish
lists etc. are solicited for
pub 1 i cat i on !
I would like to offer you some
suggestions from things I learned when
we sold our own compatible computer.
Believe me, 1 can appreciate your
d if f icul t ies.
From 1980 to 1983 we manufactured an
Apple II compatible computer . We had the
same problem you seem to have, how to
economically produce an item in small
quantities and have enough left over to
ad ver t i se .
Our solution was th<
derived by a number of
5 an i e
the other 30
mot her boar d
unpopu 1 ated
you will in
companies making Apple II compatible
systems at the time - simply sell the
either populated or
[stuffed with chips - Ed . J
case of a 99/4A compatible,
fact have to construct your
board as well as the
but everything else, from
controllers to RS232 cards
have already been built. As long as you
use a 99/4A bus, you should have no
problems with them. You could in fact
make a basic card carriage, put both the
motherboard and the video processor
within - with a space for your own
custom cards - and a bus outlet on the
back for connecting a PE Box cable so
you can use 99/4A cards too. You could
put an IBM standard keyboard connection
on the front and let users select from
hundreds of availabale keyboards in all
shapes, sizes, colors and typestyles.
If you cnstruct this card carriage out
of impact plastic with a metal IRF cage
to meet FCC standards, you could
probably build it for under $30 in
quantities of a thousand.
Additionally, hundreds of software
companies like my own would jump in to
fill the void of software for your
machine, if the initial costs aren't to
high. It would already have a
substantial software base if it is fully
assembly compatible. You would only
have to write the basics.
You could begin manufacturing and
delivery within a few weeks. Once you
start getting a return on your
investment, you could worry about fancy
items like analog/digital cards, real
time clocks and pascal cards (which are
available on the 99/4A buss). Once you
star t making money, you can wor r y about
making it a real computer.
Finally, you have a time limit. If
a new compatible isn't available by
December, then more than likely, the
community will have diminished to a
point where it isn't possible to
economically manufacture a compatible.
Selling just the motherboard would not
only work as a stopgap, it would bring
in capital, and it would give THOUSANDS
of user's hope for the long term.
Morale in this community is plumeting,
the sooner the release, the larger your
market will be !
If possible, you should reserve the
first 100-200 for software
manufacturers. The more software
available for this machine that will
ONLY run on this machine, the better
chance you have for survival. If you
a single source
are doomed to repeat
No one company can
all people. If you
machine that is
intend to become
the mistakes of TI.
be all t h i ngs to
create an open
compatible... let the hundreds of
software and hardware companies have a
crack at it, provide GOOD documentation,
you will sell a LOT of computers. That
is really the business you are
oreintating yourself towards - the
computer manufacturing business; not the
software publishing and not the add-on
market. You will have a monopoly for
some time, which yo\J won ' t have in the
other, faster moving industries.
It is very possible to turn a "dead"
market into a very successful after-
life. I sold thousands of motherboards
and complete systems before I sold the
rights. I never lost money, except at
the very beginning. People still bought
my Apple II mother boards even when
Apple was selling Apple lie's. You just
have to know how to play your hand.
A 99/4A compatible would be
fantastic. I hope your company can get
then into the hands of consumers in time
where it will be meaningful.
Sincerely, C.B., MD (name witheld)
Okay, that's fair experience. Why cant
a 4A clone or upgrade be done this way?
Are diehard TI users less capable than
other clone owners? Open architecture is
2 the key
A CONFIRMED "RUMOUR"... a note
about a new module passed this way with
no real details or address (etc.)- that
sounded good. The announcement came in
UNIVERSAL MODULE FOR THE TI 99/4A
A powerful static ram module : 48k
RAM and 3k ROM named "MAX I MEM"
This module expands the memory to
96k RAM through two sections of RAM : 32k
GRAM and 16k RAM (added to the 16k VDP
RAM fee 32k expansion memory).
MAX I MEM gives you the ability to
dump any module to disk and then run the
program from disk! No additional power
supply is needed - plugs into module
port like Widget.
MAX I MEM starts automatically through
an 8k GROM that displays choices:
1. TI BASIC (same old)
2. MAX I MEM (offers the catalog of
modules contained on disk)
3. EDITOR ASSEMBLER (an improved TI
MAXIMEM stays plugged in - no other
modules are needed. MAXIMEM holds data
even after FCTN QUIT and can load a
■tries of modules 1»: TI Writer,
MultiPlan, Extended Basic etc.
console, 32k, drive &
Price is set at *199.£>0
At a this stage, lik
develop an interest in the computer
hardware. How it operates, how to fix
some of the things that annoy you and
how to provide extra features.
I Several modifications made were
noted last issue! include locating
8k (battery backed)
8bit data bus. Slowed
25%, but has some
CONSOLE ROM ift an
RAM chip on the
things down by
i nterest i ng
modifications were made possibl
using the Hitachi HM6264LP- 15. . .
control 1 er
sh i pp i ng,
chip is just made for the TI-99/AT
hacker. It is STATIC RAM which does not
need the complex refresh circuitry of
DYNAMIC RAM and the size is just right
for the 8k blocks of CPU RAM.
ON THE DRAWING BOARD:
We are developing several
enhancements for the TI-99/4 AT
components will be mounted on a
INSIDE the computer. An additional
external power supply will be required
later. The projects will include-
Extensive CRU decoding to allow for
new facilities. Provision ul" a CRU
selectable 8k CMOS RAM chip in the DSR
area of CPU RAM from >40£>0- >5FFF .
146178 Can Inc
J4K 3M8 Canada
We haven ' t
excel 1 en t .
seen this yet.
Coupled with e
Assembler /Disassembler , source code and
fcAMDISK cards-TI owners will be free of
module slavery" forevermore should this
NEXT : 32K EXPANSION PROJECT:
From Bernie Eisner and Phil West
T.I.U.P - Australia
tarticle is "edited" tk updated]
THE ' I SADUDD ' CLUB : Anyone using a
computer which has been discontinued by
the manufacturer, automatically
qualifies for free membership of the
rapidly expanding Inter national Society
of Amalgamated Dodo Users and Dead
Ducks. ( I SADUDD ' s )
TI ISADUDD * 5 are luckier than most.
Despite the 'DODO' image, there are some
real advantages in belonging to this
Console ROM to be hardware swi tenable
between ROM and battery backed CMOS RAM.
Installation of an EPROM copier-
programmer in the computer w/ two Zero
Insertion Force socked to be mounted
above the ventilation slots.
To allow for future projects we have
decided to mount everything on a single
piece of STRIPBOARD, 23cm. wide by y
cm. deep and up to 2.5 cm. high. This
can be mounted on self adhesive
NON-CONDUCTING stand-offs on top of the
metal shielding covering the main
computer board. (In the empty space
between the keyboard and the back of the
computer . )
Only a small portion on the board is
needed for the 32k expansion. You can
mount the four RAM chips in separate
sockets and eliminate the "piggy back"
sol der i ng.
4 HITACHI HM6264LP-15 RAM CHIPS
1 pc COPPER STRIP BOARD 32 strips
wide and 23 cm. long. °i" )
2 - 4 28 pin sockets
2-4 22uF Tantalum capacitors
1 edge connector for 30+ lines
insulating stand-offs or material to
separate the board from the shielding.
single conductor wire, mu 1 t i s tr and
wire or ribbon cable, solder, fine
tipped iron, etc.
o & *
* f *
U I I 1
I 1 I I I
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IMPORTANT DISCLAIMER ( S ) .
We cannot guarantee that
modification or enhancement described
will work on YOUR computer. We develop
our projects on old equipment and accept
the risk that it may be damaged. If you
have never taken your computer apart,
handled CMOS chips or used a soldering
iron you should NOT atempt any of the
projects described (unless you can
obtain assistance from someone who has).
By modifying your equipment you will
void any manufacturers' warranties still
in force. WARNING* IF YOU ATTEMPT ANY
OF THE MODIFICATIONS DESCRIBED IN THIS
SERIES OF ARTICLES YOU DO SO AT YOUR OWN
RISK. !!!!!•! L
SOFTWARE WARNING* Moving CPU RAM
into the computer is a major change to
the TI-99/4A expansion system and may
cause some software problems. Machine
language progarms that use SPEECH or are
dependent on critical timing MAY not
our knowledge (A show
Sidney I believe
down under' in
T.I.S.H.U.G. presence this year).
Saturday, November 2nd, from 10:00 AM to
5:00 PM in the Ironwood Room. Some 21
vendors will exihibit TI hardware and
software - to the (possible) 30, 000
owners notified through the group
f f o r t s :
Which brings us around to beta testers
again... hello? Are there any console
only owners listening out there? We want
you to try something on your systems.
Drop us a line c/o BETA UNITS.
As noted above in earlier r amblings, we
will get back to the home control
subject Real Soon Now. Another board
and software system is being interfaced
over the next several weeks (given a few
minutes here) .
This expansion works fine with the
major software packages: XBAS1C,
TI-WRITER, MULT I PLAN , TI-LOGO I fc II,
T I -FORTH , EDITOR ASSEMBLER and the P-
CODE CARD - RS232, DISK CONTROLLERS
(TI, CC etc.) all been used without
any APPARENT problems.
This project should be regarded as a
'BUDGET' MEMORY EXPANSION for the
unexpanded TI-99/4A user rather than
as a replacement for existing 32k
expansion cards. If you don't have a
disk drive and controller, you should
be aware that the extra memory is not
fully usable by cassette based users.
You may only SAVE Extended Basic
programs up to 12k in size to
cassette , though the programs will
have a much larger operating space.
Flash update: The folks at MPB have a
security system and weather station
software which uses the A/D card. This
note comes from the Ottawa Users Group -
fortunately an influential, honourable
and very ACTIVE users group,
folks! Good input.
Speaking of which:
The CHICAGO AREA USERS GROUP is staging
the third annual TI FAIRE at Triton
College, River Grove, Illinois. This is
an exclusive in the users community to
A lot has happened regarding our
RAMDISK since... August. The operating
system is just about finished. (This)
is a totally brand new piece of software
that allows TI's file structures and
conventions to work with our RAMDISK.
It is not a rework of TI's disk DSR. I
cannot emphasize enough the point that
our RAMDISK works EXACTLY like a TI
floppy dirve and that it is totally
compatible with any file type in BASIC,
X-BASIC, FORTH, PASCAL and ASSEMBLY
LANGUAGE. Any software that uses a
standard TI DSRLNK will work with our
RAMDISK... The only programs that won't
work with our RAMDISK are CORCOMP's DISK
MANAGER & MILLER GRAPHICS' ADVANCED
DIAGNOSTICS. Both of these programs
ignore CRU >I000 which is one place (in
my opinion the best place) you can put
our RAMDISK. The M.G. " EXPLORER "
program is totally compatible. We
havebeen using it to debug routines for
In addition, we have included a
number of CALL statements from BASIC to
enhance the RAMDISK ' s operation. CALL
DR(drive **) sets the RAMDISK to DSK1- to
DSK 5. If the RAMDISK is at CRU >i000
then setting the RAMDISK drive number-
supplants a floppy drive of the same
number if it exists. I think the best
set-up is to have the RAMDISK as DSK1
and a floppy as DSK2. With this set-up
TI-WRITER AND E/A load their programs
from the RAMDISK. CALL MAX (maximum
sectors) sets the
sectors avai lable,
number of chips you
CALL WP/OFF- set
you to execute a
maximum number of
determined by the
use. CALL WP/ON and
the RAMDISK write
EXC (address) allows
ny machine code from
BASIC. If you have used CALL CRU/GN
(turns on and leaves the RAMDISK) you
can execute routines on the card. There
is, of course, a CALL CRU/OFF. We will
for assembly language
add a loader
artwork for the printed
is being done and a
my to manufacture the boards has
been contacted. The RAMDISK was
originally decoded at CRU >1000. Dip
switches on the card allow you to set te
RAMDISK to any unused CRU address.
Since they are unique devices, our
RAMDSK and Myarc's could be used at the
same time with no modifications. We
feel that the flexibility of both the
hardware and software on our RAMDISK
makes it a far superior design.
By the way, the contents of the
RAMDISK are maintained by three AAA
ni-cads on the board. When the PE-Box
is ON the ni-cads are being recharged.
You can take the RAMDISK to a friends,
plug it in, and use it like you brought
over a floppy!
I think the idea of a clearing house
for hardware and software information
from individuals or user's groups is an
excellent idea. One of the things that
killed TI was it's attempt to keep
everything about the machine a secret
and discourage other than TI development
for the 99/4a. Since TI bailed out new
development has come from the user-
groups. I think a more organized method
of distributing that information would
be most useful. I object to the term
'hacker', however. I think it implies
'amateur'. While we are not doing this
profit we do not consider
amateurs. We belive in a
open hardware and software
environment for the 99/4a. Our RAMDISK
package will include the complete source
code to the operating system. In
addition to extensive internal
documentation we have written a manual
detailing all of the operating system's
routines. We encourage people to alter
our system if they wish or write totally
new software for it. Since the RAMDISK
operating system is in RAM it can easily
be changed. The RAMDISK could be a
print spooler or the whole card would be
CALL statements to enhance BASIC... or
ourse 1 ves
Mnbly language programs could be
moved in and out of memory expansion
like overlays or... the possibilities
Information about ordering the
RAMDISK package (printed circuit board
and operating system for about *40.£>0)
should appear soon. I will be handling
the orders. By the way, I'm writing
this letter using TK-WRI TER loaded into
a SUPERCART and the Editor and Formatter
programs loaded on my RAMDISK. Moving
betwen programs and other functions
happen in a. blink of an eye...
S i ncer el y ,
The RAMDISK can be populated with
360k memory for DS/DD operation
according to the design layout. This is
a vast improvement for the TI. How
about a word processor with ALL the
goodies on RAMDISK, in memory without a
separate formatter, saving files to
RAMDISK at memory speeds and 6ms disk
access. . .
How about an operating system to
allow a full megabyte of memory?
Even stripping out the GROMs/ROMs
and installing a bootstrap disk loader
looking at YET ANOTHER video display
system. We're told by sources that THIS
has more bearing on release than
anything else. Perhaps a case of new
technology working against a high tech
product. Fairly common occurence to get
"lost" in all the 'interesting' ideas,
new components, processors, bells and
whistles. Oh well.
As of press time the new operating
system and the 5I2k card are not
shipping in quantity. In others words,
we haven't received them for hands on
Confirmed rumours: We are told that a
TMS 9995 based computer— on-a-card does
exist, runs and is compatible with the
PE Box & TI software. This HAS MOT been
referred to in previous issues due to
the fact that no mention was
made at the tims we talked to the
loper as to whether or not this
would ever go into production. We also
have promised not to tell due to changes
being made in the system... and the
fact that THIS "9995 SYSTEM" is from a
very smal 1 crew of systems techs who are
NOT in business
5 i gnal
Ah yes, the Auto-Start Circuit... ;
prom last issues notes, this one
the computer "turn itself on"
certain conditions (like a simple
or another power— up -on -a-
appr oach ) .
The circuit turns the computer system
on, enters Extended Basic which in turn
looks -for any file named LOAD on drive
#1. Now the possibilities here are
quite endless. A home control system
could be brought up, initialized and
operated during certain hours of the day
or, as this was originally designed
for, a BBS system could be taken on-line
for its "operating hours" - or, come up
with a database to access remotely etc.
Ron Gries sent us this one as well!
Heard that he might do a hard disk card
next - on my wish list is a "HAftDCARD"
like I saw in Byte. 10MB on a card
which fit into the slots on an IBM. No
reason that couldn't be done on the TI
One of the things we have considered
with all the circuit designs is doing
PCB artwork, parts lists, instructions
etc. Sound useful? Worth supporting
with input, designs and subscriptions?
How about a shareware concept? Kits?
Next month: An EPROM programmer design
(one of two!) that works on the TI
console as the host THROUGH the module
port. This will let you "burn" custom
modules - give your console only friends
a real thrill to see the latest assembly
program running on their 48k console. >>>
given a bank switching af-fair, you can
put 40k of EPROM on the port for some
truly extensive programs...
Also: the BBS hardware that lets you use
a dumb modem as an auto-answer auto-dial
device. Nice touch! It requires 32k and
an RS232 interface.
PLUS a number of items of interest for
TI owners, users, technical experts,
hackers (sorry, the work still carries
the wizardry label in certain circles)
et al. See you then. Pass the data
TH£ ZCLAY umLL
"TO EHT6JLY& tu PcCT.
List - Auto Start Circuit tttt
556 Dual Timer
14 pin socket
914 Signal Diodes (2)
10K Ohm Resistor (1/4 watt)
1 Megaohm Resistors (2) - 1/4 wati
10 MFD Electrolytic Capaci
1 MFD Tantalus Capacitor
12 VDC Reed Relay
List - Power Supply tttt
LM317T Adj. Vol tag© Regulator (+)
Bridge Rectifier - 1.4 A 50 PIV
470 MFD 50 V Electrolytic Capacitor
1.5K Ohm Resistor (1/2 watt)
220 Ohm Resistor (1/2 watt)
12 VDC Reed Relay (-for modem power)
AC Transformer (8 to 20 VAC nominal)
R/D Computing is published monthly by
Ryte Data in Haliburton, Ontario.
Copyright 1985. All material contained
herein is taken from sources believed
to be accurate. No
with credits by
publ i cat ion .
or misprints is
may be reprinted
users groups -for
Articles dealing with Texas Instruments
99/4A and 9900 based computers are
published. Special attention is given
to data on upgrading and modifying the
4A console t* system. Information and
material for consideration is solicited
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BOX 210 MOUNTAIN STREET
HALIBURTON, ONTARIO K0M ISO