This mini forum is intended to provide a simple means of discussion about the Tandy Radio Shack  TRS 80 PC-4 computer. If you want to share your own experience or memories, or add relevant information about this system: post a message!

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.

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.

Rich, I''m interested in the interface. What would you sell it for?

is there any value to these anymore? got computer, printer and cassette interface all in good condition. frcwrx@msn.com

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?

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.

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