The model 3 is generally regarded as the successor to the Model 1.
Its two 5.25" floppy disk drives could convert model 1 disks.
Initially Radio Shack wanted to sell both the model 1 and 3 at the same time, but the FCC forced them to stop selling model 1. Is so they were discontinued because of the excessive radio noise that they put out.
However, the Model 3 wasn't FULLY compatible with the model 1. There were differences in ROM which meant some programs had to be converted, especially those machine language ones that made ROM calls.
Model III configurations, by Dave Thompson:
TRS-80 Model III was sold in multiple configurations.
No hardrive configurations included:
Model III with Level 1 ROM, 8k RAM sold for US$799. Model III with Level 2 ROM, 16k RAM sold for $999.
The first floppy drive cost $849, and could store 168k. The second drive was cheaper, and could store more. The price difference is due to the first one included the drive controller. The increased space on the second drive (189k) was due to the first drive must also contain some TRS-DOS (the operating system).
Brandt Daniels adds:
There was also a TRS-80 VideoTex Computer terminal in 1980.
Mark Fowler reports:
I worked for a company in 1982 that had integrated a 5MB, and later a 10MB hard disk into the TRS80 Model III. It was then programmed in FORTRAN-66 as a dedicated medical records system, to mimic the pegbook accounting system in use in the 1980's. We introduced green phosphor, and later amber phosphor display tubes. Some systems were used with a modem to do simple email-type applications, and to access various bulletin boards.
My parents bought me a TRS-80 Model III as a high school graduation present in 1981. That was a sweet machine at that time. Of course, I didn''t have floppy disks because those were too expensive. OTOH, I did have the new *triple speed* audio cassette that could load data at a zippy 1500 bits per second!
I quickly outgrew the 16K of RAM and upgraded first to 32K and then maxed out at 48K. I still have the machine, and I still have the Model III ROM Commented book that has the assembly source code for the L2 ROM.
Not seeking to sell...just posting for shared interest. :-)
Wednesday 4th June 2014
This was my first computer. I bought it used (or perhaps I should say that my mom bought it for me as I didn''t have money at the time (Sound familar??)) for $1000 used. Came with two caes of disk, bunch of Load-80 tapes and several books. That night I was up until 5:00 A.M.w when my mom made me go to bed. I woke up 3 hours later and was back on the machine. True, the graphics sucked even at the time, but the games were still fun. I also had fun BBSing (but for some reason it wasn''t fun when the phone bill came looking as thick as a phone book ...just kidding, but the bill was no laughing matter. Still, it was fun trying to get on that popular BBS that ALWAYS had a busy signal....*SIGH* I tell you kids have SO EASY now a days with the Internet. Able to listen to any song you want right away w/o having to call a radio station asking the DJ to put it on wondering f he/she would, never getting a busy signal when you want to go online. In a weird way it was fun trying to get on that populat BBS$ LOL
How many of you remember paying $40 for a box of ten 5 1/4" floppies at Radio Shack? That''s something I don''t miss!!! I do remember an Elephant floppy I had that I used to boot the system. I used that sucker for a year at least and that floppy NEVER gave me a gram of trouble.
Monday 23rd July 2012
Rob (California, USA)
I have a TRS80 III and the wide printer. Purchased back in 1985. Last used about 1995. Has been stored in excellent condition. Lots of cables and misc. Several boxes of books, magazines and software for this computer. If someone is interested in them please contact me. email@example.com
Tuesday 21st February 2012
Greg Brackett (United States)
TRS 80 MODEL III
Tandy Radio Shack
END OF PRODUCTION
BUILT IN LANGUAGE
TRS-80 Level II BASIC
Full-stroke keyboard with separated numeric keypad
Zilog Z80 then Z80A
16 KB (up to 48 KB)
32 or 64 columns x 16 lines
128 graphic characters
Tape (500 or 1500 bauds), Centronics, RS232
BUILT IN MEDIA
Zero, one or two 5.25'' disk-drives.
TRS DOS (other OSes were available : New DOS, LDOS, MultiDOS, ...)
Built-in power supply unit
Various Tandy peripherals
No disk model : AU$1450 (Australia, 1981) $2495 in 1984 for a complete system with 2x360 KB drives, TRSDOS, 64kb Ram, software and printer