--- title: Tandy Radio Shack TRS 80 PC-4 categories: - Computers types: - Pocket origins: - Japan years: - '1982' cpus: - HD61913 CMOS VLSI params: name: TRS 80 PC-4 image: /media/museum/photos/tandy_pc4_system_s1.jpg company: /companies/tandy-radio-shack company_name: Tandy Radio Shack specs: - label: NAME value: TRS 80 PC-4 - label: MANUFACTURER value: Tandy Radio Shack - label: TYPE value: Pocket - label: ORIGIN value: Japan - label: YEAR value: '1982' - label: END OF PRODUCTION value: Unknown - label: BUILT IN LANGUAGE value: Basic interpreter - label: KEYBOARD value: 53 keys with numeric keypad - label: CPU value: HD61913 CMOS VLSI - label: SPEED value: 455 kHz ceramic resonator used as system clock - label: RAM value: 1 KB (544 bytes for Basic programs) up to 2 KB - label: ROM value: 12 KB - label: TEXT MODES value: 1 line x 12 chars plus a 4 digit seven segment display part - label: GRAPHIC MODES value: None - label: COLORS value: Monochrome LCD - label: SOUND value: None - label: SIZE / WEIGHT value: 165 (W) x 71 (D) x 10 (H) mm / 116 g (with batteries) - label: I/O PORTS value: |- 12-pin expansion port for printer and cassette interface\ 11-pin internal slot for memory module - label: POWER SUPPLY value: 2 x CR-2032 lithium batteries - label: PERIPHERALS value: 1 kB RAM PACK, cassette interface, mini thermal printer (from Tandy or Casio) - label: PRICE value: Unknown tabs: - photos - links - docs photos: - title: PROMOTIONAL BOX subtitle: '' text: '' image: /media/museum/photos/tandy_pc4_box_s1.jpg 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-4 OWNER'S MANUAL url: null cover: /media/museum/docs/couvs/tandy_pc4_%20owners-manual.jpg text: |- **PC-4 OWNER'S MANUAL**\ written by Radio Shack  compiled/archived by Unknown\  type of document : ZIP\  size : 5,3 MB\  source : [Ira Goldklang's TRS-80 Revived Site](http://www.trs-80.com) - title: PC-4 SERVICE MANUAL url: null cover: /media/museum/docs/couvs/tandy_pc4_service-manual.jpg text: |- **PC-4 SERVICE MANUAL**\ written by Radio Shack  compiled/archived by Wade Fincher\  type of document : ZIP\  size : 3 MB\  source : [Ira Goldklang's TRS-80 Revived Site](http://www.trs-80.com) - 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 :** - title: PC-4 CASSETTE INTERFACE OWNER'S MANUAL url: null cover: /media/museum/docs/couvs/tandy_pc4_%20cassette-interface-owners-manual.jpg text: |- **PC-4 CASSETTE INTERFACE OWNER'S MANUAL**\ written by Radio Shack  compiled/archived by Unknown\  type of document : ZIP\  size : 2 MB\  source : [Ira Goldklang's TRS-80 Revived Site](http://www.trs-80.com) comments: - author: Sanjin Grandić (Croatia) date: Thursday 10th November 2022 text: I was born in 1966 and was living in Paris when this little "marvel." I was like 13-14 yrs old when my mother bought it for me it cost 778 FF (Francs frnçais)which was a quarter of the minimum agreed salary in France, so it was not cheap when it first came out but what a joy to have this in class, the teachers thought it was a scientific calculator (which it was lol) but so hand for history AND maths or other exams with the answers "hidden in the box" behind the looks of calculator lol. I wrote a short program that displayed a clock running late less than a sec per day in 45 minutes. - author: Greg Bzdell (Canada) date: Monday 24th May 2021 text: I have a working Tandy PC-4 that belonged to my oldest brother. I popped some new batteries in 3 months ago and it worked. Nice to be programming in BASIC again. - author: jds date: Thursday 14th March 2013 text: Rich, I''m interested in the interface. What would you sell it for? - author: Rich H (Ohio USA) date: Saturday 5th January 2013 text: is there any value to these anymore? got computer, printer and cassette interface all in good condition. frcwrx@msn.com - author: Edward (Russia) date: Tuesday 29th November 2011 text: |- MK-85 and Casio (or this Tandy) looks like two coins because soviet engineers simply take the interface modules (screen and keyboard) from cheaper pocket computer (Casio PB-100) and placed over their own platform $ PDP-compatible 16-bit chipset. Result is strange $ big computer (MK-85 can work with very big numbers $ over to 10^4000) is closed in calculator''s cage with small screen and ugly keyboard. Add there lack of any interfaces to make a program backup (there are no tape recorder or printer ports in MK-85) and you can fully imagine this strange pocket computer. Programs are saved in 2K volatile memory divided to ten parts without any chance to make a hardcopy.\ Many of MK-85 still work today like new. Think, what today''s pocket devices can still work over 20 (MK-85 manufactured up to 1991) or near 30 years like Casio? - author: Paradroyd (Missouri, USA) date: Tuesday 3rd May 2011 text: I have one of these that I bought new not too long after it was released in 1982. I used it in college classes and did some basic programming on it. The PC4 that I have still works fine in as of May, 2011. I just changed the batteries last year and powered it up to make sure it still works. I used to have the cassette interface for it too, but that was lost years ago in a move. - author: User (Russian Federation) date: Friday 19th June 2009 text: |- Looks similar to Electronica MK-85 made in USSR (1986) http://www.leningrad.su/museum/show_calc.php?n$172\ http://ru.wikipedia.org/wiki/$D0$AD$D0$BB$D0$B5$D0$BA$D1$82$D1$80$D0$BE$D0$BD$D0$B8$D0$BA$D0$B0\_$D0$9C$D0$9A-85\ http://mk85.narod.ru/about.htm related: - /museum/tandy-radio-shack-trs-80-pc-1 - /museum/tandy-radio-shack-trs-80-pc-2 oc_id: 1003 source: url: https://web.archive.org/web/20230608084457/http://www.old-computers.com/museum/computer.asp?c=1003 date: '2023-06-08' --- The Tandy PC-4 Was a rebadged version of the Casio [PB-100](/museum/casio-pb-100/).\ Apart from the brand/model plate, the design and features was identical to the original Casio model.