To help us on our story, we'll use the boy mascot from the PC-4 Programming Manual. He's getting caffeinated up and should be raring to go any minute, and yes, his quips and quotes are all directly scanned from the manual. Before we begin, click the picture on the far left for a 117K sampler of all that as available in the Pocket Computer line from my collection. All of the units you will see pictured are in the author's possession.
This site was last modified on 13 January 2008.
I appreciate receiving your comments, corrections, fan mail and offers of cash. Send it all to email@example.com. I would also gratefully ask you to obtain my permission before posting or redisplaying photographs from this site on yours. Thank you! -- Cameron Kaiser
|Are you getting rid of Pocket Computer equipment? Please don't throw it away! I am always interested in your extra or unwanted Pocket Computer systems, peripherals, paraphernalia and manuals. Please send me E-mail at firstname.lastname@example.org with your desired arrangements and let's see if we can't work something out!|
The first of the "true" Pocket Computers, excluding higher-end calculators and the like, was the Sharp PC-1210 (1980). (I do not count the 1977 Sharp PC-1201 as the first, despite the PC-1201 being labeled as a Pocket Computer, as it doesn't have a full character set.) Based on the form factor of the Sharp EL-5100 calculator series, the PC-1210 offered 896 bytes of memory and the BASIC programming language (in a simplified variant called S'-BASIC "S Prime BASIC," S being short for Sharp), using a 4-bit dual CPU system, for an MSRP of US$229. The unusual RAM total came from a combination of its 1024-nybble RAM (1024 * 4 bits = 512 8-bit bytes), and an additional 128 bytes in each of the three display chips. Because of this odd memory layout, only an effective 400 bytes were available for user programs although the parsimonious nature of S'-BASIC did mitigate the limitation somewhat; even considering its size, however, the memory constraint of the PC-1210 was fairly dire for the price point and Sharp followed with the PC-1211 shortly after. The PC-1211 used the same architecture but had 1536 bytes of main RAM (3072 nybbles) along with the 384 bytes of display memory for 1920 bytes total RAM and 1424 bytes for user programs.
Choosing BASIC as the programming language for the new line was an extremely sound decision. It transcended the sometimes opaque programming methods and "languages" used by other programmable calculators, and gave the impression of using a full desktop machine as virtually all desktop microcomputers of the day (such as the Apple II, Commodore PET and the Tandy Radio Shack TRS-80) used it as their primary programming language as well. Sharp's BASIC also established the two-mode paradigm that virtually all Pocket Computers use where the computer lives in a calculator-like RUN mode on start up, allowing "instant" arithmetic like a standard calculator as well as program execution, while a switch or key sequence will switch it to PROgramming (or WRiTe) mode where program lines can be entered or edited. This elegant division of modalities made it possible to have a Pocket Computer replace a calculator for quick one-offs, yet not have BASIC clashing with immediate expression evaluation.
To keep data sets small, the Sharp units also introduced the concept of "fixed memories" -- every unit had 26 variables available, either string or float, accessed as A-Z. A letter could only be one type or the other (no separate A and A$), and array indexing operated on the 26 "memories" directly (so that A$(3) was actually an alias to C$). For programs needing greater dataspace, "flexible memories" allowed allocating free memory as additional variable space accessed also by array indexing, and some later units could even do this dynamically under program control. These variable conventions and the "fixed" versus "flexible" memory allocation were another feature set also maintained in all of the succeeding units. (String support was limited to 8 character variables in the PC-1210/1 and thus would be generously described as deficient, something not addressed even partially until later models.)
Now that the memory
capacity was no longer as crippling a limitation, the PC-1211 variant was
considerably more popular and attracted Tandy's attention, who was
looking for a small portable computer to complement their newly popular
Color Computer and TRS-80 computer lines.
Then as now, Tandy's main interest was to resell rather than develop
internally if it could possibly avoid it. (This is still true of the modern
Radio Shack corporation.) For this reason, the PC-1211 was simply rebadged
as part of the TRS-80 line and was introduced as the Pocket
Computer PC-1 with an MSRP of $249.95 in 1980. Dubbing S'-BASIC as "Pocket
BASIC," Tandy heavily hyped its desktop-like qualities and expansion options
throughout their entire sales network and their Radio Shack retail store
With this massive international exposure, the PC-1 was extremely popular
and Tandy simultaneously imported most of the Sharp peripherals, in particular
the printer and tape interfaces, to rebadge
and sell as well as software custom for the unit.
The PC-1 was obviously produced in some numbers as it is
one of the easiest units to come by; Tandy followed it with heavy cassette
software support and a collection of books, guides and manuals for the
hobbyist. It was later reduced to $149.95.
However, what Sharp lacked and what Tandy wanted was a ultra-value-priced unit. For their low-cost model, Tandy made the fateful decision to split the Pocket Computers into separate architectures and recruit instead from Casio's competing line in 1983. The first of the Casio derivatives was the ultra-low-end 1983 Pocket Computer PC-4, based on the Casio PB-100. Although hobbled by a 4-bit CPU, only 544 bytes of RAM (of a total of 1K [2048 nybbles]) and a 12-character LCD, it had a very attractive small form factor, low power requirements, and most important to Tandy, an enticingly low price tag. It is probably for this reason that the PC-4 sold in large numbers and became nearly iconic of the line, even making it to the movies -- Egon Spengler (Harold Ramis)'s computing device of choice in Ghostbusters was a PC-4 with a cassette attachment. The leads of the cassette attachment were wired in a most grotesque fashion into his coat so that the device could just dangle. (Unfortunately for enthusiasts of the paranormal, the PKE meter attachment was not sold in the United States.) In 1985, the PC-4 was re-released in an upgraded version with new ROMs, but alas no additional memory, in a chimaeric form partially based on the Casio PB-100F. Unique for the line, the PC-4 introduced the concept of independent segmented program spaces to the Pocket Computer family (its ancestors were all one-program units) and for the first time what could be considered to be a rudimentary internal filesystem. Naturally, its own selection of external peripherals was readily available, including a practically essential 1K RAM pack.
Despite its impressive specifications, the PC-2 was not very approachable to the casual enthusiast due to its size and cost, and furthermore neither the PC-2 nor the PC-4 were backwards-compatible with the PC-1 because of their dissimilar architectures. Fortunately, Sharp had already issued a faster and smaller follow-on to the PC-1211 in the form of the 1982 PC-1250, using a 8-bit CPU that was otherwise fully upwards compatible with the S'-BASIC of the PC-1211. This version became the first of the Pocket Computer PC-3 line released later in 1983 after the PC-4, placed in the midrange market slot, but the RAM capacity was not much better than the PC-1 it was intended to replace (despite having 2K of RAM, only 1438 bytes were free for user programs). Fortuitously, Sharp quickly followed the PC-1250 with the 4K PC-1251; Tandy followed suit and released the PC-1251 as a redesigned Pocket Computer PC-3 (the PC-3A, "now with 4K RAM") in 1984.
Together, the PC-2, PC-3 and PC-4 represented the "triumvirate" of the Tandy Pocket Computer lines, with a unit positioned in each of the three key markets. They enjoyed wide support from the Radio Shack retail stores and were easily the three most popular units by far; in fact, they are the three units I recommend in three different targets -- see the individual pages for why:
For the Casio users, Tandy chose three units from the Casio stable, calling them the Pocket Scientific Computers and emphasizing their additional specialized mathematic functions. In the flagship slot, Tandy chose the FX-780P and its expanded sibling FX-790P and released them as the Pocket Scientific Computer PC-5 and Pocket Scientific Computer PC-6, respectively, in 1985 and 1986. Sleek and impressive units on the outside with a generous 24-character LCD inside, they were nevertheless plagued by poor build quality, an impractical split keyboard design, dubious internal features and kludgy expansion options (using the PC-4 peripherals, but requiring an inelegant link cable to handle the physical case incompatibilities). The 4K PC-5 lasted less than a year before it was rapidly eclipsed by the 8K PC-6, which was expandable to 16K to boot, and thus the PC-5 is correspondingly much harder to find by collectors. (Nevertheless, despite their multiple iniquities, the beautiful exteriors of both units make them very popular items on the used market today and NOS PC-6s often command prices nearly as high as when they were sold new!)
In the value slot, Tandy selected the horrific Casio FX-5200P and released it as the Pocket Scientific Computer PC-7 simultaneously with the PC-6. Intended to replace the PC-4, the PC-7 was actually a gigantic step backwards, taking the worst elements of the PC-5/6 design and combining them with the worst elements of the PC-4 (especially the cramped RAM and screen) -- certainly what was already considered a liability in 1983 would be considered even worse in 1986, but what was most damning of all was that that it had no expansion options of any kind.
However, Tandy wasn't finished insulting its loyal customer base and for an encore finished the line in 1987 with the disappointing Pocket Computer PC-8, based on the Sharp PC-1246 (to distinguish it from the Casio models, the Scientific moniker was dropped and the old designation restored). Compared with the PC-7, the PC-8 was a welcome improvement, but compared with the PC-3 it was designed to replace, it was an utter travesty. Retreating to a four-year-old design (the PC-1245 and the succeeding PC-1246 were originally released in 1983 as low-cost versions of the PC-1250!), the PC-8 had a smaller screen and even less memory than even the original 2K PC-3 (a pathetic 1278 bytes available for BASIC). Its only saving graces were that at least it could use the PC-3's peripherals directly, and its reasonably rugged form factor.
Although the PC-6 was a reasonably bright profit spot despite its compromises, the otherwise generally lackluster showing of the later members of the line had a predictable effect on sales, and the choice of models demonstrated a clear preference towards quick and cheap rather than powerful and useful which unfortunately matched Tandy's growing ambivalence towards its non-PC computer lines in general. With the success of the Tandy 1000 showing the way towards today's Wintel hegemony, even the venerable Color Computers' days were clearly numbered and the (intentionally?) ailing Pocket Computers thus had no executive chance for survival. The last model to be sold was actually the long-lived PC-6, which outlasted all the other members of the line until around 1991, when it too was laid to rest.
However, the spiritual descendants of the Pocket Computers are obviously the modern PDAs. While Windows Mobile may inspire fits of nausea in the susceptible user, it and other PDA operating systems such as Palm OS and Symbian are the operational evolution of the concept of the "peripheral brain." I couldn't live without my Palm Zire 72 in my pocket for various technical texts, my pocket organizer (a humourous thought about this is in the clip from the PC-4 Programming Manual at right), my address book and a few games here and there. Self-hosted programming languages like Plua give back the programmability of the Pocket Computer, while the modern PDA's improved host connectivity nimbly supersedes most peripheral needs. The Pocket Computers offered a lot of computing power in a small space for the day, and today's PDAs deliver on a similar promise.
Perhaps the Dynabook will one day be in reach. When it is, we will remember
the Pocket Computers as part of the ancestry that brought it to us.
For all these reasons, plus conversations at cocktail parties and maybe picking up a geek gadget girl/guy, a Pocket Computer is still a fun addition to one's collection. Here are a few general tips to acquiring and maintaining them, with more specific notes on the specific model pages.
Fortunately, Sharp and Casio did release AA battery-powered printers which thus completely avoid this problem -- but unfortunately Tandy never imported them. Nevertheless, at least one of them can be found fairly easily on the used market; see the PC-1/3/8 page for more.
Speaking of printers, be sure to spec paper for your unit correctly. Many of the models are thermal, but not all, and some use slightly smaller paper sizes. An office supply store may be able to help you if you bring them the spent spool for comparison, or you might be able to fashion your own by unwinding a larger reel down to the printer's capacity and lopping off an end to fit.