💾 Archived View for uscoffings.net › retro-computing › systems › Tandy › t › 1400ltdk.txt captured on 2022-06-04 at 00:42:23.
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Sb: #1400 MEMORY/RAMDISK/ETC.
Fm: PETER A. ISAACSON 73500,1256
To: all
Observations on the 1400LT.
How does one open up your 1400 to get to the innards?
I used Norton Utilities to look at the data on the system disk, sector-
by-sector and found the words 'Above Board'. This I found on a backup
copy of my system disk in Cluster 288, Sectors 587-587. Is Tandy not
telling us something about the internal architecture?
I opened up the famed 1400 'Mystery Port' and took a peek inside. The
small card cage can hold two cards, on of the slots is occupied by a card
that says 'EXMEMORY' on the lower right-hand corner of the component side
of the card. The IC's are labeled as such:
IC300-IC303 are socketed and have an 'F' printed with a line above and
below it.
IC300 - MB81C4256-12P IC301 - MB81C4256-12P
8713 V15 8713 V15
IC302 - MB81C4256--12P IC303 - MB81C4256-12P
8712 V05 8713 V15
IC304 - TOSHIBA IC305 - 7041A0 IC306 - TDK
TC74HC08P M74HC04P EDL 040
8651H 75F1
If you remove this board with the power off and then re-boot, you only
have 256K and NO RAMDISK! That means that 384K and another 128K are on
this board!.
The card-edge connector has 26 contacts arranged in this order:
1-----------25
2-----------26
From what Tandy is telling us (as far as I know) is that there is no way
to expand the memory beyond 640K+128K. That's what they said about the
Model 100's 32K. Yet you can get up to 1MEG using the Traveling Software
Booster Pak!
Come on Tandy! Stop feeding us this BS! NODOZE.SYS exists, why don't you
tell your employees' about it!
I'm mad as hell and I'm not going to take it anymore!
Peter A. Isaacson
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Sb: #18735-1400 MEMORY/RAMDISK/ETC.
Fm: Mike Nettles 72401,1046
To: PETER A. ISAACSON 73500,1256 (X)
Read the current issue of PCM. It has an article, with pix, that shows how to
open the complete system to install a LiteDrive. It's pretty informative.
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Sb: #18735-1400 MEMORY/RAMDISK/ETC.
Fm: George Sherman 72401,527
To: PETER A. ISAACSON 73500,1256 (X)
Dear Peter Are you serious about getting 1 meg out of your Model 100? What's a
Travelling Software Pack? How do I accomplish the same feat.
Thanks, George Sherman
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Sb: 1400 hard drive battery
Fm: Rusty Hill 76220,1602
To: all
Hi Folks !
Let me introduce myself. Amoung other things I wrote the article on
installing the CMS hard drive into the 1400 which appeared in the June PCM.
A few comments about the drive:
It is designed to take more than 70G forces. I've dragged mine all
er the place in my consulting business. Everything BUT mud, an awful lot of
banging around. After a year and a half I'm still using the same drive. NO
crashes !
The ideal of using a conductive strap is great.
New Pathways has a better fix for reducing the charge time and still
Protecting the $80 battery. A 150 mA. current limiting diode for $20.00 They
make them and I've not found another source. However the 750 mA transformer
originally supplied by Tandy will not drive the 1400 with a hard drive and
charge the battery. With the hard drive spinning the 1400 draws about 1 A.
There is a fix.
150 mA Diode .......$ 20.00
3 A Power supply ...$ 70.00 (diode included)
Installation .......$ 15.00 (R554 shorting included)
Sources:
New Pathways
140 Walnut St.
Shrewsbury, MA. 01545
(508) 842-4437
BODEX
224Main
Marlboro, MA. 01752
(508)485-5115
(508 481-1027 [D [D Computer Plus
Littleton, MA. (there maybe others)
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Sb: #Hard drive 1400LT
Fm: Jim White 72407,1031
To: all
I am one of the purchasers of the Tandy 1400LT that took advantage of the great
price offered. I am now looking for a hard drive and have several questions.
Is there an inexpensive hard drive and how hard would it be to install in the
1400LT? Any help will be appreciated! Jim
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Sb: #20087-#Hard drive 1400LT
Fm: Charles Robertson 70130,330
To: Jim White 72407,1031 (X)
you can try any of these...
Tandy 1400 Hard Drives
Computer Options Unlimited - 1-201-469-7678
Weltec - 1-800-333-5155
Discount Computer Supplies 1-800-537-3539
Tradewind Peripherals (Traveldisk-external) 1-818-896-6634
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Sb: #20113-#Hard drive 1400LT
Fm: Jim White 72407,1031
To: Charles Robertson 70130,330 (X)
Charles: Thanks for the info. I will call and inquire about hard drives. Do
you have any preferences or experience with any of the vendors mentioned? Jim
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Sb: #20087-Hard drive 1400LT
Fm: Rusty Hill 76220,1602
To: Jim White 72407,1031 (X)
I wrote an article for the June PCM. hIt discusses installing a Hard drive in
the 1400lt. The only REAL drive manufacturer I know of is CMS Enhancements.
Their drives from non-Tandy sources go for $760 and up.
There is a resistor on the power supply board which needs to be shorted in
order for the disk controller to work correctly it is r554.
There are two ways to re-install protection for the battery.
1) place a 27 ohm resistor, paralell (sp?) SHOCKY diode in the battery
from the controller. If it is in the red lead the band on the
diode should be away from the battery. This resistor should be
1 to 2 watts.
2) Get New Pathways Mark 31A current limiter/protector and insert in
the battery lead. The Mark 31A acts like a 10 ohm resistor,
Shocky diode combination until the battery starts to pull
150 mA, About the maximum safe current level for a 12v. NICAD.
It clamps the current at this level. Thus it provides a faster
charge and protects the battery from over current damage.
Your charger needs to deliver over 14 volts at the battery terminal and be able
to provide 1.5 to 2 amps.
These can be gotten from:
New Pathways 140 Walnut St. Shrewsbury, MA. 01545 (508)842-4437
BODEX 224 East Main Marlboro, MA. 01752 (508)481-1027
Computer Plus P.O. Box 1049 Littleton, MA. 01460 (508)486-3193
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Sb: #20130-Hard drive 1400LT
Fm: Charles Robertson 70130,330
To: Jim White 72407,1031 (X)
jim,
no...they are just advertisers in PCM Magazine (i don't have a 1400)