--- title: Tandy Radio Shack TRS 80 Model 4P categories: - Computers types: - Portable origins: - U.S.A. years: - '1983' cpus: - Z80A params: name: TRS 80 Model 4P image: /media/museum/photos/tandy_model4p_system_2.jpg company: /companies/tandy-radio-shack company_name: Tandy Radio Shack specs: - label: NAME value: TRS 80 Model 4P - label: MANUFACTURER value: Tandy Radio Shack - label: TYPE value: Portable - label: ORIGIN value: U.S.A. - label: YEAR value: October 1983 - label: BUILT IN LANGUAGE value: None - label: KEYBOARD value: Typewriter style, 70 keys with numeric keypad and arrow keys - label: CPU value: Z80A - label: SPEED value: 4 MHz - label: RAM value: 64 or 128 KB - label: ROM value: 4 KB - label: TEXT MODES value: 32 or 64 x 16 / 64 x 40 / 80 x 24 - label: GRAPHIC MODES value: None - label: COLORS value: Monochrome - label: SOUND value: Buzzer - label: I/O PORTS value: Parallel, Serial, Expansion bus - label: BUILT IN MEDIA value: |- 2 x 5.25'' SS SD 180 KB floppy drives\ Very late models had double-sided TEAC drives - label: OS value: TRS-DOS 6.0 to 6.2, LS-DOS 6.3, CP/M - label: POWER SUPPLY value: Built-in power supply unit - label: PERIPHERALS value: Built-in 300-baud modem, external HDD - label: PRICE value: $1,790 tabs: - photos - hardware - emulators - links photos: - title: MODEL 4P subtitle: '' text: '' image: /media/museum/photos/tandy_model4p_front_ebay_2.jpg - title: FRONT subtitle: '' text: '' image: /media/museum/photos/tandy_model4p_front_ebay_1.jpg - title: KEYBOARD subtitle: '' text: '' image: /media/museum/photos/tandy_model4p_keyboard_1.jpg - title: BACK subtitle: '' text: |- from left to right: \- RS232C connector\ \- I/O bus\ \- parallel port image: /media/museum/photos/tandy_model4p_back_1.jpg - title: CLOSED subtitle: '' text: '' image: /media/museum/photos/tandy_model4p_closed_1.jpg hardware: - title: REMOTE UNIT ACTIVE subtitle: Serial# 26-1210 text: |- This rare unit is meant for teachers to control up to 16 TRS-80 Model 1 from a another TRS-80 equiped with min-disk. All the controled TRS-80 model 1 must be equiped with Level II. It cost 2895fr (France, 1981) image: /media/museum/hardware/tandy_trs80-m1_remote-unit-active.jpg - title: NETWORK II BOX subtitle: p/n 26-1211 text: |- This box allowed up to 16 TRS computer to be networked. Three network boxes were released by Tandy (I, II and III).\ The Network II required verbal communication between the server operator and the remote user, and data transfer had to be completed one user at a time.\ The network III allowed automated control of the network so that users could easily access programs and data stored on the server's storage device. Thanks to **David Sutherland** for the pictures. image: /media/museum/hardware/tandy_network2_s1.jpg - title: DMP-200 subtitle: '' text: 80-column, 100 cps dot matrix printer. image: /media/museum/hardware/tandy_model3_dmp200_s1.jpg - title: DAISY WHEEL PRINTER II subtitle: Serial# 26-1158 text: |- This is a high-quality printer meant to be used with wordprocessors. Some interchangeable daisy-wheels were available (Courrier, Elite, Madeleine). It could print 163 characters per line (34cm), at a 43 cps rate. It cost 9595fr (France, 1981) image: /media/museum/hardware/tandy_trs80-m1_daisy-wheel-printer-2_1.jpg - title: LINE PRINTER I subtitle: Ref# 26-7017 text: |- This printer was a custom version of the Oki Microline 80.\ Printed lower and upper case on paper rolls or listing paper (24cm wide) from 40 to 80 columns/line, at a speed rate of 28 lines/minute. It cost 716 Euros in 1981 (France). image: /media/museum/hardware/tandy_model1_lineprinter1_s1.jpg - title: LINE PRINTER III subtitle: Serial# 26-1156 text: This printer can print lower and upper case, at a speed rate of 120 c/s, on paper up to 38cm wide. It is conceived for intensive use ! It cost 9950fr in 1981 (France). image: /media/museum/hardware/tandy_trs80-m1_line-printer-3_1.jpg - title: LINE PRINTER VI subtitle: Serial# 26-1166 text: |- This large printer can print lower and upper case, graphic characters and symbols at a speed rate of 100 c/s ! This is definately a professional printer. It cost 5495fr in 1981 (France). image: /media/museum/hardware/tandy_trs80-m1_line-printer-6_1.jpg - title: TP-10 THERMAL PRINTER subtitle: Box text: '' image: /media/museum/hardware/tandy_trs80_tp-10_thermal-printer_box.jpg - title: EXATRON subtitle: Stringy Floppy drive text: |- The Exatron Stringy Floppy (ESF) was a low-cost data—storage system that fitted the gap, between cassettes and disk drives.\ The system was based on a miniature endless—loop tape cartridge called a "wafer".\ The amount of data that could be recorded on a wafer depended on the length of tape in it, typically, a 50—foot wafer could hold at least 40 KB of programs or data. **Matt** reports to us:\ A curiousity about the model 1, CPU SPEED had a direct relatonship with STORAGE CAPACITY. if you doubled the clock speed of your MODEL 1 CPU you doubled the amount of data you could store on your stringy floppies. this is a feat that no other computer no matter how many ghz you have in your PC can do today without using compression. Thanks to **David Sutherland** for the pictures image: /media/museum/hardware/tandy_model3_exatronwafer_s1.jpg emulators: - title: David Keil's TRS-80 Model III/4/4P Emulator Page url: http://discover-net.net/~dmkeil/trs80/model4.htm platform: MS DOS text: This program emulates a complete TRS-80 - title: Matthew Reed's TRS-80 Emulator Web Site url: http://www.arrowweb.com/mkr/ platform: MS DOS text: This page offers shareware versions of a TRS-80 Model 4 emulator and a TRS-80 Model 1-2 emulator - title: TRS-80 Model III/4 Emulator url: http://www.vavasour.ca/jeff/trs80.html#model4 platform: MS DOS text: This TRS-80 Model III/4 Emulator is a commercial product - title: 'xtrs: TRS-80 Model I/III/4 Emulator for Unix' url: http://www.tim-mann.org/xtrs.html platform: Unix / Linux text: xtrs is a Radio Shack TRS-80 Model I/III/4/4P emulator for Unix and the X Window System - title: TRS-80 Level I BASIC in a browser url: http://www.vavasour.ca/jeff/trs80.html#simulator platform: Other platform text: With this Java emulator, you'll be able to write a BASIC program directly in your browser! - title: Ira Goldklang's TRS-80 Revived Pages url: http://www.trs-80.com/trs80-e.htm platform: Multiplatform text: A complete list of TRS-80 emulators for various platforms ! - title: MESS url: http://www.mess.org platform: Multiplatform text: MESS emulator also emulates a TRS-80 systems links: - title: 8bit-micro.com - Online TRS-80 Computer Magazine url: HTTP://WWW.8BIT-MICRO.COM text: Online Magazine dedicated to the TRS-80 and other Vintage - Monthly Issues - title: David's TRS-80 Page url: http://freespace.virgin.net/david.sampson/ text: '' - title: Ira Goldklang's TRS-80 Revived Pages url: http://www.trs-80.com/ text: Lof of infos about all TRS-80 computers - title: Java TRS-80 Model 1 BASIC Interpreter url: http://ganley.org/software/trs80.html text: '' - title: Mike's Personal Computer Museum url: http://personal.nbnet.nb.ca/mclays/trsmod1.html text: Level 1 & 2 Basic summaries, Tandy time-lines, price-list, etc ... ! - 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! - title: The TRS-80 Home Page url: http://www.kjsl.com/trs80 text: Full of infos - title: Tim Mann's TRS-80 Page url: http://www.tim-mann.org/trs80.html text: Infos, tools and home of xtrs, a Model I/III/4 emulator for Unix - title: Web Wiz CAPTCHA url: http://www.webwizcaptcha.com text: Discussion about Tandy computers comments: - author: Steve mills (Corvallis or) date: Monday 4th June 2018 text: Trs80 model 4p for sale - author: CJ (Virginia) date: Sunday 1st April 2018 text: |- I own a 4P myself, and thought I would add some more specific technical details - The 180K disk drives it uses are Tandon brand drives, model TM50-1, belt-driven.\ The Z80A CPU is SGS Thompson branded, model Z8400AB1. - author: Jeff Gillis (united states) date: Monday 17th July 2017 text: Unbelievably, I actually have the original cardboard box for a TRS 80 model 4P that I recovered from my folks attic where it sat undisturbed for decades. The internal packing material is long gone, but the box itself is in very good shape. I was going to flatten it and recycle it unless someone wants it. Any takers? - author: Marcus N. (Germany) date: Monday 12th December 2016 text: Dear Mr. Bryant, do you still have these manuals and Softwaredisks? I''m about to buy a TRS-80 4p with nothing except the defective machine... I would be so happy if you could send it over here to Germany by Mail postage - of course all on my cost :-) - author: Dean Notarnicola (NJ, USA) date: Tuesday 10th November 2015 text: 'Harry and John: Do you still have those Model 4P computers?' - author: Harry Bryant (United States) date: Saturday 29th August 2015 text: I have a TRS80 4P and assoiated manuals and software. I''d gladly donate it to a hobbiest/museum for the cost of shipment. - author: Chuck Rose date: Thursday 15th January 2015 text: My model 4P had double sided drives just like the 4D. I developed with it mostly in CP/M mode because it had the bigger market compared to the model 4. - author: John E Iacono (USA) date: Monday 13rd October 2014 text: I have a 4P that has not been turned on for about 20 years. Also several hundred dsdd floppies, if anyone is interested. We used it in our accounting company for several years. - author: Richard date: Thursday 10th November 2011 text: I have this computer but do not have a power cord. Would any power cord work? - author: Richard date: Thursday 10th November 2011 text: I have this computer but do not have a power cord. Would any power cord work? - author: James (USA) date: Saturday 4th June 2011 text: I am still in possession of the Model 4P that my father purchased for me in 1984. (my junior year of HS.) The unit is still in functional condition, although the floppy''s are getting worn out. Anyone know where I could find replacement disks for it ?? - author: Charles Rose (Maine, USA) date: Wednesday 21st October 2009 text: Ahhh yes, the TRS-80 4P. I had one of these machines as my main computer in the mid/late 80''s. I used it to keep the books for my freelance software company as well as developed some software for it (mainly a Video renting system) in Model III mode. I have not-so-fond memeories of hauling this thing through various airports to make connecting flights. I think the only thing that made it portable was the handle in the case lol. It was seriously a very heavy ''portable'' machine. - author: Andy (Washington) date: Tuesday 20th June 2006 text: Well, went to my local Goodwill today and bought one of these babys for a smokin price of 5 bucks! Anyone interested in snaging this? related: - /museum/radionic-model-r1001 - /museum/sysdata-eletronica-jr - /museum/tandy-radio-shack-trs-80-model-12 - /museum/tandy-radio-shack-trs-80-model-16 - /museum/tandy-radio-shack-trs-80-model-4 - /museum/tandy-radio-shack-trs-80-model-i - /museum/tandy-radio-shack-trs-80-model-ii - /museum/tandy-radio-shack-trs-80-model-iii oc_id: 1083 source: url: https://web.archive.org/web/20230608220843/http://www.old-computers.com/museum/computer.asp?c=1083 date: '2023-06-08' --- The Model 4P was the transportable version of the [Model 4](/museum/tandy-radio-shack-trs-80-model-4/). Apart from the case and display sizes, technical features were almost identical to the Model 4's. The dual half-sized floppy drives were still single-sided versions but the keyboard, which slided underneath the computer, was far better than the one of the desktop version. The external floppy drive connector was removed, as well as the Model 3 ROM, but a ROM image could be loaded from diskette to run Model 3 programs. An optional 300-baud modem could be also installed into the machine. Very late models had double-sided TEAC drives. --- Further information from **Greg Trotter**\ I used a Model 4P for many years. It was pretty much identical to the Model 4 in functionality, except for:\ \- Portability, of course\ \- No Model III ROM (but you could load an image of the ROM into the RAM and reboot, giving perfect compatibility)\ \- It did have a modem card slot, except that the card edge provided power only; the outward face of the card had a short DC-25 serial cable, just long enough to get to the serial port of the 4P.\ \- There was no cassette interface on the 4P.\ \- The keyboard was indeed superior; I liked it better because it was corded and could be moved to any angle. Of course, portable just meant "easier to transport." The entire unit weighed about 28 pounds, if I remember correctly. I lugged it through airports, and it fit quite comfortably in the overhead bin.