Thermal Baby Wedges, boy I’ve sure been on a kick all week and having a lot of fun. For the record, I still haven’t run down a set of batteries – these thermal babies really seem to sip the juice. I poked the only other collector I know of who owns one of these Brother EP’s (Robert Messenger), and was rewarded with a nice look at his machine, which filled in some of the questions I had about the progression of features over the series. With that and some Googling, I was able to piece together a rough timeline of the short-lived EP series:
Late 1982 – Brother EP-20
The very first Electronic Thermal Battery-Operated Typewriter, simple dot-matrix font, one-line memory editing. It is marketed by Brother as a “personal printer” even though it had no I/O port with which you could hook it up to a computer. That feature came later with the EP-22.
Late 1983 – Brother EP-22
Introduced in late 1983, the EP-22 adds an I/O port to allow printing from a computer (and reportedly, allows streaming of text in memory over a modem, a popular feature with on-the-go reporters). It also has additional memory and functions related to the I/O buffers. It still prints the same draft-quality dot-matrix font as the EP-20. That doesn’t appear to change until the EP-4x series.
The EP-44 is introduced in 1984 with a slightly changed shell shape and color switched to white. It is unknown if the font is improved (Update: just got one and yes, it has a much better 24-pin NLQ typeface), but it does incorporate more buffer memory and retains the I/O port of the EP-22, giving it the ability to be used as a computer printer.
Later in 1984, Brother introduces a new design for the EP series shell, gives the EP a higher resolution print head and does away with the calculator-style keyboard, replacing it with a much better full-size keyboard.
I came across a couple of ads in the December, 1984 and November, 1985 issues of Popular Photography listing the Brother EP models available for sale at those times. The EP-20 seems to have continued to be sold up until 1985, when it drops out of sight.
1987 – Brother EP-5, EP-150
I haven’t found out much about the EP-5 and EP-150, even though I have the parts and service manuals for both. The technical manuals make no mention of the functions or capabilities. I presume they are roughly similar to my Sharp machine, meaning much higher resolution fonts, and probably the ability to do several kinds of fonts. The I/O port from the EP-22/44 is not mentioned, and probably does not exist on these models.
Beyond 1987/1988, I find no mention of any additional models. I did find mention that Brother’s thermal fax machine models were struggling at that time with poor sales, and it seems likely that the public’s disenchantment with thermal print technology and the quick rise of ever-better laptop computers in the 1980’s probably killed off the EP-Series typewriters. Certainly by the end of the 1980’s, the Baby Wedge era had ended, less than a decade after it had begun. Thermal printing technology had basically all but vanished from the consumer market and from then on was mainly used in low-cost industrial applications such as graphing printers (seismometers, EKG machines) and cash registers/ATMs.