website/content/museum/tandy-radio-shack-trs-80-pc-1.md

---
title: Tandy Radio Shack TRS 80 PC-1
categories:
- Computers
types:
- Pocket
origins:
- U.S.A.
years:
- '1980'
cpus:
- Sharp CMOS SC43177
params:
  name: TRS 80 PC-1
  company: /companies/tandy-radio-shack
  company_name: Tandy Radio Shack
  specs:
  - label: NAME
    value: TRS 80 PC-1
  - label: MANUFACTURER
    value: Tandy Radio Shack
  - label: TYPE
    value: Pocket
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1980'
  - label: BUILT IN LANGUAGE
    value: BASIC interpreter
  - label: KEYBOARD
    value: 57 keys, QWERTY calculator type with numeric key-pad
  - label: CPU
    value: Sharp CMOS SC43177 and SC43178 (4 bits)
  - label: SPEED
    value: 256 kHz
  - label: RAM
    value: 1920 Bytes; 1424 steps / 178 memories available
  - label: ROM
    value: 11,2 kB (?)
  - label: TEXT MODES
    value: 1 line x 24 chars. (LCD screen)
  - label: GRAPHIC MODES
    value: None
  - label: COLORS
    value: Monochrome
  - label: SOUND
    value: CPU controlled piezo buzzer, 1 tone with fixed frequency and duration
  - label: SIZE / WEIGHT
    value: 175 (W) x 70 (D) x 15 (H) mm / 170 g
  - label: I/O PORTS
    value: 9 pin expansion port for printer and cassette interface
  - label: POWER SUPPLY
    value: 4 x 1,35 V button cell MR44 or similar
  - label: PERIPHERALS
    value: |-
      26-3503 cassette interface\
      26-3505 printer / cassette interface (mechanical dot printer)\
      CTR-80A cassette recorder (generic)
  - label: PRICE
    value: $230
  tabs:
  - photos
  - adverts
  - links
  - docs
  photos:
  - title: CLOSE-UP
    subtitle: ''
    text: ''
    image: null
  - title: WITH MANUAL
    subtitle: ''
    text: Tandy PC-1 with user manual and soft protective case.
    image: null
  adverts:
  - title: FRENCH ADVERT (1980)
    subtitle: ''
    text: Dated december 1980
    image: /media/museum/pubs/tandy_trs80-model1_pub_grande-ouverture.gif
  links:
  - title: RadioShackCatalogs.com
    url: http://www.RadioShackCatalogs.com
    text: Here, you can actually/virtually flip-through the pages to view the content of every RadioShack catalog!
  docs:
  - title: PC-1 - OPERATION MANUAL
    url: http://www.trs-80.com/trs80-hw.htm
    cover: null
    text: |-
      [**PC-1 - OPERATION MANUAL**](http://www.trs-80.com/trs80-hw.htm)written by Radio Shack

       compiled/archived by Wade Fincher\
       type of document : PDF\
       size : 4 MB\
       source : [Ira Goldklang's TRS-80 Revived Site](http://www.trs-80.com)

      **... READ THE ONLINE VERSION BY CLICKING BELOW :**
  - title: TRS-80 POCKET COMPUTER & CASSETTE INTERFACE - SERVICE MANUAL
    url: http://www.trs-80.com/trs80-hw.htm
    cover: null
    text: |-
      [**TRS-80 POCKET COMPUTER & CASSETTE INTERFACE - SERVICE MANUAL**](http://www.trs-80.com/trs80-hw.htm)written by Radio Shack

       compiled/archived by Pete Bumgardner\
       type of document : PDF\
       size : 3 MB\
       source : [Ira Goldklang's TRS-80 Revived Site](http://www.trs-80.com)

      **... READ THE ONLINE VERSION BY CLICKING BELOW :**
  - title: PRINTER/CASSETTE INTERFACE FOR TANDY POCKET COMPUTER
    url: http://www.trs-80.com/trs80-hw.htm
    cover: /media/museum/docs/couvs/tandy_pc1_printer-cassette-interface.jpg
    text: |-
      [**PRINTER/CASSETTE INTERFACE FOR TANDY POCKET COMPUTER**](http://www.trs-80.com/trs80-hw.htm)written by Radio Shack

       compiled/archived by Wade Fincher\
       type of document : PDF\
       size : 495 KB\
       source : [Ira Goldklang's TRS-80 Revived Site](http://www.trs-80.com)

      **... READ THE ONLINE VERSION BY CLICKING BELOW :**
  comments:
  - author: Chris Daniels (USA)
    date: Wednesday 16th December 2020
    text: It used four MR44 1.35 V Mercury button cells, which are no longer manufactured. The WEINcell MRB675 is a "zinc air" substitute that works well. Several other batteries with the correct voltage will fit, but they are for fundamentally different applications, like hearing aids, and are made to discharge constantly. They will not stop when the device will turn off, and will not last very long.
  - author: Bill Potter (United States)
    date: Monday 17th April 2017
    text: I have a PC-1 and still use it to this day. I have a friend repairing the printer batteries and I will attempt to re-ink the ribbon. I am looking for a digital recorder that will work with the cassette interface.
  - author: Dave Parker (USA)
    date: Monday 2nd April 2012
    text: I have a PC-2 with the printer /cassette interface. The pens in the printer use a water based ink and I seriously doubt that you would be able to find replacements. Your best bet might be to refill the ink pens. I haven''t tried it on mine yet, but inkjet printer ink might work fine. If it''s too saturated, you might want to thin it with distilled water.
  - author: Questor (USA)
    date: Sunday 27th November 2011
    text: |-
      @Emily - I am actually going to attempt a repair for the cloudy issue on my PC1 in the next couple of weeks... If you want me to let you know how it goes, send me a PM thru the old-computers.com forums (Username: Questor).

      Wish me luck!
  - author: Emily (New Zealand)
    date: Sunday 18th July 2010
    text: I have my fathers Radio Shack TRS-80 Pocket Computer. I am getting new batteries for it so I can check that it works. The screen is a little cloudy- any advice on how to fix this?
  - author: Ronnie Fillers (Greeneville, TN)
    date: Wednesday 21st March 2007
    text: 'where did you find the ink cartridge pens for the sharp computer - #EA-850B for the CE-150 printer? Please advise, because I have not been able to find them.'
  - author: Rob Sobkoviak (Earth)
    date: Wednesday 21st February 2007
    text: I have one of these computers--got it when I was about 12 years old....it was an "upgrade" to my TI-55 scientific calculator. I was the toast of the 7th grade until a few of my friends ended up spending thousands on the Apple \]\[+ :)
  - author: Jeff (USA)
    date: Saturday 4th October 2003
    text: |-
      I still have mine.. although I have tried to replace the batteries, but it still fails to operate. Mine, however, is the Sharp version of the TRS. I have the notebook adapter that includes a thermal printer, minicassette data drive, and a nice little case. I also have several programs that run electrical calculations and statistical data.

      The earliest PDA?
  related:
  - /museum/tandy-radio-shack-trs-80-pc-2
  - /museum/tandy-radio-shack-trs-80-pc-4
  oc_id: 937
  source:
    url: https://web.archive.org/web/20230403061028/http://www.old-computers.com/museum/computer.asp?c=937
    date: '2023-04-03'
---

The "TRS-80 Pocket Computer" was the first pocket computer Tandy/Radio Shack distributed. Nowadays, it is often referred to as the TRS-80 PC-1, so as to differentiate it from its successor, the TRS-80 PC-2 (and following), which is a clone of the Sharp PC-1500.

The TRS-80 Pocket Computer was custom manufactured by Sharp Corporation, and is technically identical with the [Sharp PC-1211](/museum/sharp-pc-1210-1211-1212/) (see there for more technical information). There were some minor differences: The colour style was a bit different, with gray and black prevailing instead of brown, and of course with a Radio Shack type label; moreover, the computer came with a soft (instead of hard) protective case, and an additional Quick Reference Card.

The peripherals were - of course - the same as for the Sharp models: The cassette interface unit (Catalog Number 26-3503), and the printer and cassette interface (26-3505 ), which incorporated a single needle mechanical dot printer.

Special thanks to **Roman von Wartburg** and his [site](http://retrocomputing.ch/) for information and picture.