The TRS-80 PC-2 Pocket Computer

Tandy sold eight different models of Pocket Computers from 1980 to 1987. This included the PC-1 (1980), PC-2 (1982), PC-3 (1983), PC-4 (1983), PC-5 (1985), PC-6 (1986), PC-7 (1986) and PC-8 (1987). Despite being only the second model released, the PC-2 was by far the most powerful (and the largest) of the TRS-80 pocket computers.

All of the TRS-80 pocket computers were based on computers designed either by Sharp or Casio (depending upon the model). The TRS-80 PC-2 was a re-branding of Sharp’s PC-1500 Pocket Computer. It was introduced at a relatively pricey $279.95 which would nearly double if you were to also purchase the combination printer/cassette expansion unit.

Tandy Pocket Computers were designed to be calculator-sized portable computers. They resembled calculators in many ways and were able to operate as calculators and/or as computers.

“Besides being one of the smallest computers that Radio Shack provides, the TRS-80 PC-2 is one of the most powerful and versatile computers of its size available anywhere. It’s powerful capabilities, as well as its “expandability”, make it the ideal personal computer for business, scientifgic, engineering, or personal use.” — TRS-80 Pocket Computer PC-2 Owner’s Manual

Specifications

  • 66 key keyboard
  • 26 character LCD display
  • 156 x 7 graphics capability
  • Integrated Speaker and tone generator
  • Integrated Real Time Clock
  • 1.3 Mhz 8 bit CMOS CPU (LH-5801)
  • 16K ROM including the built-in BASIC programming language
  • Approximately 3.5K of RAM built-in
  • Expansion area (RAM/ROM expansion)
  • A Cassette/Printer interface
  • Battery powered using four AA batteries
  • Support for a 6 volt DC adapter
  • Dimensions : 7-11/16″(W) x 3-3/8″(D) x 1″(H)
  • Weight : 0.83 pounds including batteries

Features

The LH-5801 CPU is similar to other 8 bit CPUs of it’s time such as the 8080, Z80, and 6502. It is not directly compatible with any of them.

The BASIC programming language built-in to the PC-2 (Extended Pocket BASIC) allowed direct access to the CPU unlike other Tandy pocket computers. The direct memory access allowed programmers to push the machine to it’s limits rather than to be confined to the built-in Basic Interpreter.

The PC-2 is the only pocket computer from Tandy which allows direct access to the memory. This enables native programming of the PC-2 in machine language.

The PC-2 was able to use RAM expansions which were officially offered in 4K and 8K capacities from Tandy. Sharp produced a battery-backed 16K RAM expansion card for the PC-1500 that would also work with the PC-2. However, it was too large to fit in the PC-2 unless you left the expansion bay cover plate off.

“We are convinced that the Pocket Computer is the wave of the future. Miniaturization and portability continue to be major design goals in all areas of electronics: TV, stereo, amateur radio, calculators, auto, home, etc. The same applies to computers.” — TRS-80 Pocket Computer Programs

Admittedly you would need a very large pocket to contain a PC-2. Despite this, the PC-2 was set apart from the other Tandy Pocket Computers in several ways.

The larger keyboard and screen make typing and viewing the screen more comfortable than the smaller pocket computers. The larger case allows the use of standard AA batteries — which is much more convenient than using button cells.

A built-in speaker and tone generator empowers the PC-2 to produce sound, albeit in a limited way.

One of the most enduring features of the PC-2 is the display. A total of 1,092 pixels can be turned on or off individually in a 156 x 7 pixel matrix. The built-in BASIC programming language provides full support of the dot-addressable display.

Bathyscaph

You can type the following BASIC program into the PC-2 and experience a simple game with graphics and sound. For several more games like this be sure to check out the Sharp PC-1500 computer (TRS-80 PC-2) resource page.

The instructions are simple : Pilot your submarine through the cave and reach the exit as fast as possible. If you crash, you start again and your time adds up.

1 "BATHYSCAPH"
2 "Move : up/down arrows
8 CLS :WAIT 0:CLEAR : DIM A$(0)*20:GCURSOR 10
10 FOR I=0TO 13
20 RESTORE 999 RND 16
30 READ A$(0):GPRINT A$(0);
40 NEXT I:GCURSOR 154:GPRINT "141C":TIME =0,H=3,G=8
50 FOR P=2 TO 154:GCURSOR P-2
60 Z$=INKEY$ :IF Z$="" THEN 85
70 H=H-SGN (ASC Z$-10.5)
80 G=INT (2^H .5)
85 S=R:R=Q:Q=POINT P
90 GPRINT S;GOR R;GOR Q
100 IF (QAND G)>0 GOSUB "CRASH"
110 BEEP 1,0,1:NEXT P:IF H<>3 THEN 50
120 CURSOR 0:PRINT "TIME :";TIME *100;" mn ":FOR I=1 TO 5
125 BEEP 1,105,80:BEEP 1,82,80:BEEP 1,68,80:NEXT I
130 END
200 "CRASH"FOR I=0 TO 30:POKE# 64000,RND 256-1:NEXT I
210 CLEAR : P=2,G=8,H=3:RETURN
1000 DATA "7163470F1F0F47637160"
1001 DATA "717371787C7E78606141"
1002 DATA "776341085D5D08416371"
1003 DATA "00404040606070707060"
1004 DATA "00406070787C7C704040"
1005 DATA "0060787E7C7870604000"
1006 DATA "70707070604078706070"
1007 DATA "61634341406071737361"
1008 DATA "0103070F0703416070"
1009 DATA "07070303416170787060"
1010 DATA "07600760406070794060"
1011 DATA "41414141181841414141"
1012 DATA "41636363616041430341"
1013 DATA "01034347676763434101"
1014 DATA "18181818414143431840"
1015 DATA "00010301000103070361"

Online Resources

“The small desktop computers of the late 1970s and early 1980s will be the museum pieces of the late 80s and early 90s.” — TRS-80 Pocket Computer Programs

Conclusion

With it’s powerful BASIC, direct memory access, graphical display, tone generator and expansion capabilities the TRS-80 PC-2 was a portable powerhouse when first released. The PC-2 was discontinued in 1984 but remains today as the single most powerful model of the full range of Pocket Computers released by Tandy.

Comments

  1. Still got my TRS 80 PC-2. Dont have the Plotter/Cassette interface or power pack any more but the little blighter is otherwise still running. Haven’t used it for over 20 years or more but since I found the PC-2 owner’s manual on the internet I shall re-aquaint myself with my dear old friend. All I need to do now is scrounge for a compatible power-pack.

  2. Still have mine too. Got it in ’83. Learned basic poking, peeking and ended up learning assembly because of it. I expanded mine with the rs-232 interface as well as the printer plotter and a 16k ram/rom module (switchable.) I connected to a 300 baud modem back in those days. Remember the BBSes back then? I remember looking at an ARC file for the first time an being completely stumped as to what it was. Let me tell you using the PC-2 online was no easy feat, either! It’s terminal program was written (ML) into the RS-232 and required quite a bit of protocol knowledge before you could use it. We sure were gluttons for punishment back then, weren’t we?

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