NewDeal Technical Support Document 272
Star Gemini 10x
Star Gemini 15
Star NX 2420
Starjet, Starjet 48
The Star Gemini 10x (not the NX-10) may double-space (insert extra line feeds) when printing using the Text Mode Only option in version 1.0 of the software. The Gemini 10x printer driver uses the horizontal tab function to position the print head horizontally. On the Gemini 10x, the Set Horizontal Tab code causes a linefeed to occur. This was corrected in version 1.2.
If your Star NX-2420 printer doesn't work properly, i.e. it leaves a 1/8th inch horizontal line somewhere in the document or 1/4" blank lines, it could be related to the ROM chip in the Star printer. The first series of printers to be shipped from Star had a bug in the printer ROM that causes this problem.
To correct this problem, you need to get an upgrade ROM (V1.7) from Star and install it into the printer. You can request an upgrade from Star Micronics. Call their tech support number 908-572-3300 and ask for the FIRMWARE EPROM UPGRADE. Then open your printer up, remove the old ROM, and install the new one. Make sure the that both the computer and printer are powered off before attempting to replace the ROM.
If you don't feel comfortable changing the chip yourself, then take your printer to the nearest Star repair location and they will take care of it. This might even be covered under the warranty. We obtained the new ROM and tested it successfully.
Star calls the firmware upgrade an EPROM and apparently they ship it without instructions. The EPROM socket is under the removable cover for the font cartridge just below the ribbon cassette (page 8 of the printer manual). The socket has more terminals than the chip which should be installed as far to the right as it will go. On the EPROM there is a paper sticker, it should say something like ZBL 1.3. The current version is 1.7.