★ HARDWARE ★ Electronics Eight Bit Centronics Interface ★ |
| Imprimante Divers - Electronics Eight Bit Centronics Interface (Computing with the Amstrad) |
A bit extra for your printer port WHEN they sent me the Glendower Electronics Eight Bit Centronics printer interface for review I was a little perplexed. As we all know, the Amstrad already has a Centronics interface built-in at the printer port, requiring only a ribbon cable to connect it to the printer. So a second interface is like putting wellie boots over wellie boots. Could the office be testing me? Or was this an explosive way of terminating my services? Anxiously I read the documentation. Now usually manufacturers go on for pages about the wonderful things you can do with their product, with a hasty final paragraph on how. But there was not even a hint of what it did among the page and a bit of elaborate installation instructions, nor any manufacturer's address. But I finally figured it out. It's an eight bit interface. Printer wise people will know that the Amstrad printer port only sends 7 of its eight bits, which means that you can't send codes above 127 and also makes graphical printing difficult. But the Glendower interface adds the 8th bit, so that you can send codes up to 255. Now you can get at the block graphics built into your printer, or use the interface to send machine code to some other peripheral. The interface is a solidly constructed black box, about 100 by 75 by 40mm deep, with a short ribbon cable running from it to an edge connector for the printer port. The other side has a through connector and a long ribbon cable is supplied for connection from this to the printer. The 5 volt cable from the monitor plugs into a socket on the interface, and a similar cable from the interface plugs into the normal 5 volt computer socket. A very short software program drives the interface, which then responds to PRINT or LIST (#8). For the technically minded, data is present when the strobe goes low. It will be reset in approx 1 microsecond. As soon as "strobe low" is recognised by the receiving device it must set Busy to High. The interface will not place data on the port until the receiver signals readiness by setting Busy to Low. Verdict: Sadly it's not a two-way interface, and at £21.50 it is a little pricey in comparison to similar products.
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