The Timex/Sinclair 2040 Personal Printer

After a long wait, the Timex/Sinclair 2040 Personal Printer is finally available in the United States at most outlets that carry the TS1000. However, there is both good news and bad news with regards to this little beauty, I’m afraid.

At $99.95, the 2040 is the cheapest printer on the market designed specifically for the TS1000 or ZX81. Although it is by no means comparable to an 80 column, 8 1/2 inch paper cruncher, its 4 inch, 32 character format is adequate for its intended purpose, to produce legible hard copy of displays and program listing.

The package consists of the printer’s own separate 24 volt power supply and the printer unit itself. A short cable connects the printer to its edge connector interface which plugs into the rear of the computer. A male edge connector exlends from the back for interfacing with the 16K RAM pack or other peripherals in a piggy -back fashion. The chasis is a bit larger than that of the Sinclair printer (i.e., the British predecessor).

To operate the printer there are but two switches: “on/paper advance” and “off.” All you have to do is load the paper (one free roll included), plug the printer in, press the “on button” and you are ready to print.

The rest of the operation is controlled by the three keyboard commands: LPRINT works exactly like the PRINT statement, printing on paper whatever follows the command. LLIST will list your entire program in the familiar LIST for mat. COPY (used usually in the immediate mode) will print whatever happens to be on the screen at the time.

A built-in self-testing routine (activated by presssing “off” while holding the on/ advance confirms the proper operation of the printers innards by printing row after row of 8’s and l’s.

The cable from the interface to the printer carries only seven lines: printer select, DO, D6, D7, RD, WR, and Ground. Printer select is generated in the interface itself with a single 74LS10 clip which pulls printer select low (i.e., enables printer operation) when A7 is high, A2 is low (=FBh), and IORQ is low. The printer, incidently, works as an I/O port as far as the Z80 microprocessor is concerned, using OUT (FB), A and IN A, (FB) commands.

The 25 meter rolls of thermal printer paper retail for 3 for $5.95, but availability has not been that good, at least in the Boston area. I suspect this should improve with time as distribution becomes more wide spread.

The printing operation itself is relatively quiet, fairly fast (about two lines per second), and very clean and legible. Figure 1 shows a sample printout of the character set.

I have found it extremely handy for printing out listings and machine code routines. Debugging is much more readily accomplished on a paper copy than on a screen only 24 lines long.

So, in summary, the good news is good: the TS2040 is a sophisticated, yet simple and reliable little machine that any serious user should consider.

Now, the bad news. By the time this review is printed this may be old news, but when I bought my printer (May) I was disappointed when my Byte-Back 64K RAM would not function in the upper 32K area with the printer attached. It worked just fine in the usual 16K area, but even with the printer unplugged it would not accept poking RAMTOP to 6535.

This problem is not confined to the Byte-Back RAMs only, since Memotech 32K units have had a similar problem (and I would imagine others have as well). When I called Byte-Back, they were aware of the problem and had it solved within a week or two. It seems that in order to pass FCC interference regulations Timex made some rather unorthodox circuit adjustments that had the effect of slowing down signal transmission times on the data bus. This helps decrease unwanted RF emissions from the printer, but it also leads to a bus conflict that may cause problems with memory devices that pull ROM CS high to utilize the 8-16K and 32-48K memory areas (where the ROM repeats itself).

Timex’s response to this problem has been sort of a “tough luck Charlie” attitude, since their 16K RAMs work just fine thank-you. The problem, however, is not insurmountable. Byte-Back gave me a very simple circuit modification to do which resulted in the speedy resolution of the situation.

Since each company probably uses slightly different decoding routines in the RAM, I suggest that those of you with 32K or 64K units consult your manufacturer as to how to perform the necessary modificatioms. By now most of them should have figured out a way around Timex’s little adjustment, but I give ByteBack a big pat on the back for being one of the first companies to solve this problem. (Incidentally, if you have one of the imported Sinclair printers I understand that there is no high-mem pack incompatability, and you should have no problems combining the two in your system.)

The FCC faux pas aside, the 2040 is an inexpensive alternative to a full-size line printer, a good value for the money, and a worthy companion for your Timex Sinclair computer.