[sci.electronics] Radio Shack Model 100

cjp@megatek.UUCP (Christopher J. Pikus) (03/05/91)

	I'm thinking of getting a R/S Model 102(?) and am interested
in what hardware/software mods have been done to one. Would some
of you netters be so kind as to post details of some of your Mod100
projects. In particular I would be interested in:

	1. memory expansion

	2. memory expansion (ROM) as in what applications did you 
embed into rom for personal use.

	3. did you do anything useful with the 300 baud modem?

	4. any hardware additions?

	5. any neat system software written?


	thank you very much..


-- 
Wax your board, waste your brain, and pray for waves...
Christopher J. Pikus,               Megatek Corp.
INTERNET:     cjp@megatek.uucp      San Diego, CA
UUCP:         uunet!megatek!cjp or ucsd!megatek!cjp

PZ2@psuvm.psu.edu (David L. Phillips) (03/05/91)

In article <1809@valhalla.megatek.uucp>, cjp@megatek.UUCP (Christopher J. Pikus)
says:
>
[STUFF DELETED]
>        5. any neat system software written?
>
>
A while back, the maintainer wrote of an archive for anonymous FTP:
      ux1.cso.uiuc.edu
Appropriate directory is    /incoming/tandy100
Lots of good stuff.  Check the file <filelist>.

hardarso@polk.cs.unc.edu (Kari Hardarson) (03/06/91)

In article <1809@valhalla.megatek.uucp> cjp@megatek.UUCP (Christopher J. Pikus) writes:
>
>	I'm thinking of getting a R/S Model 102(?) and am interested
>in what hardware/software mods have been done to one. Would some
>of you netters be so kind as to post details of some of your Mod100
>projects. In particular I would be interested in:
...
    My company (Hugur of Iceland) is doing the following to Tandy 102's:
We remove the keyboard, and replace it with a membrane keyboard, we
install a main transformer and recharger so the machine charges Ni-Cads
when main power is available and runs off them during power failures.
Also: We remove the OS-ROM and put a socket there, we then install
EPROMs that contain programs written in C, compiled using a C
compiler that produces ROMable code for the Tandy102. The compiler is
made by King Computing of California. We also use the barcode interface.
We reverse-engineered a barcode program included with the barcode wand
from radio shack and wrote a better one that is pollable and doesn't 
hang up the machine until something has been scanned. 

    What is the result of all this?  A time clock that collects trans-
actions at the factory entrance and transmits them to a PC over a 
serial cable or modem once a day. The cassette tape motor relay we
use as a switch  for ringing the coffee-hour bell at presettable
times. We've mutilated 400-500 Tandys so far!

PS: When we replace the OS-ROM we replace the character set at the
same time since Icelandic has 20 special characters.

Kari
-- 

Kari Hardarson         |  Twas brillig and the slithy toves
217 Jackson Circle     |  did gyre and gimble in the wabe...
Chapel Hill, NC 27514  |  (Jabberwocky by Lewis Carroll)

gordon@prls.UUCP (G Vickers) (03/07/91)

In article <1809@valhalla.megatek.uucp> cjp@megatek.UUCP (Christopher J. Pikus) writes:
>
>	I'm thinking of getting a R/S Model 102(?) and am interested
>in what hardware/software mods have been done to one. Would some
>of you netters be so kind as to post details of some of your Mod100
>projects. In particular I would be interested in:
>

      Model 100 ?   YECK !

      I used about fifty of these in a data collection project. I became
   VERY familar with the thing as I had to look into the ROM and
   DOS byte by byte.  I am less familiar with the 102 since my
   program (written with a cross-assembler on a VAX and force feed
   to the Model 100) ran on it without modification.

     I beleive I found some OS bugs in the model 100, I do not know if
   they were fixed in the 102.  When I called Tandy (before the 102
   was introduced), they really didn't seem to care about the bugs).

    The Model 100 (102) is fine for taking notes in class and then
   transfering the notes to a bigger computer for editing and saving.
   I've had to cold start the 100's and 102's so many times, I would
   not consider any RAM files safe until they are saved to disk or
   to another machine.

     If you plan to use the serial port, or anything else that can cause
   interupts, be forwarned that (at least in the 100) the machine may
   go to la-la land and require a cold start that will wipe out all
   directory entries you have created.  Under these same conditions,
   a less sever (but more common) problem may occur: the keyboard
   doesn't always recognize keypresses.  The machine uses an 8155 to
   drive a buss that scans/reads the keyboard, sets/reads the clock,
   and some other things (I don't have my notes handy).  It is a cleaver
   scheme but during one small portion of the clock read routine, the
   buss can remain hot should an interupt occur.  This problem was
   first discovered while running an BASIC program.  The fix, if you
   are running interupt intensive programs, is to write your programs
   in assembler and include you own interupt code, i/o code, math
   fuctions, etc.  i.e. don't let the ROM code run  :-)

 DISCLAIMERS:
  Since dis-assembling the ROM code is prohibited by the license
     agreement each owner is bound too, do not assume I did it anyway. 
     Don't ask me for any such listing since Tandy's copywrite would
     prohibit sharing it if I did have one.
  These are my opinions only. They also rely in part upon
     information provided to me by those who worked for me on this
     project so I COULD BE WRONG.
 

Gordon Vickers 408/991-5370        {mips,pyramid|philabs}!prls!gordon  
Signetics in Sunnyvale,Ca (USA)
The Earth is a complex array of symbiotic relationships: Every extinction,
  whether animal, mineral, vegetable, or cultural hastens our own demise.