Talking about Parallel Port, maybe everyone doesn't care, is it the interface that connects the printer or scanner and other peripherals? Nice. We all know the role of the parallel port, but have you noticed its settings? Do you really understand its settings? Have you encountered a failure caused by improper setting? The author has never seen it in a few cases of incorporation.
Fault Phenomenon 1: One PII450 microcomputer, when printing a document in Windows 98, an irregular offset, such as an offset between the upper portion of the Chinese character and the middle or lower part.
Machine configuration: 64MB PC 100 memory, diamond 810 motherboard, MAXTOR 8.4GB hard disk, OKI 8340C 24 pin width line printer.
Fault resolution: First, it is suspected to have a problem with the printer, so, reinstall the driver, but the fault is still. Next, take a closer look at the system of each device in the Device Manager, everything is normal. Is it Windows 98 with a problem? With questions, the author tried again in pure DOS 6.21, and the fault is still. It seems that it is not a software problem. Is the printer failed? Carefully read the manual of OKI 8340C, fully inspect the printer, and the printer is intact. The possibility of the printer break needle is denied through the Patch24.com breakage maintenance program included in UCDOS 6.0. There is no problem to solve a print cable. In the case of a doubt, the author accidentally remembacted the settings of the parallel port. So, look at the BIOS and find that the parallel port is set to "ECP EPP", then look at the manual, OKI 8340c supports EPP, the original problem is here! After the EPP is changed, the fault is finally excluded.
Fault Phenomenon 2: A Celeron 450 (Celeron 300A Press 100 × 4.5 overclocking) microcomputer, after continuously scanning multiple photos in Windows 98, report "scanner error" or inexplicably crash.
Machine configuration: MSI MS-6163 motherboard, ACER 320P (optical resolution 300 × 600dpi, EPP interface) scanner.
Fault Solution: Due to overclocking, it is suspected that the instability caused by overclocking, so that the frequency is reduced to the rated frequency, the fault is still. It is doubts that the driver of the scanner has problems, but the fault is still in reloading. Carefully check the connecting cable and there is no loose phenomenon. Any conflict or problematic devices are not found in "Device Manager". During the discharge process, the author finds that as long as it is a scanned list, the scanner does not have any problems, which means that the possibility of the scanner itself is small. Since the failure occurs when it is repeatedly scanned multiple photos, is it related to temporary space and virtual memory? After inspection, environmental variable TEMP settings, "System Monitor" analysis results also indicate that virtual memory settings are reasonable. Even manually set virtual memory can also solve the problem. So, where is the problem? I thought I thought in parallel settings. The BIOS of the MSI MS-6163 motherboard is the Award BIOS 4.51pg on October 20, 1998, and its parallel port is set to EPP. Again, the parallel port mode is EPP 1.7, is the Acer 320P scanner work unstable in this mode? After the parallel port is changed to EPP 1.9, the fault is completely excluded.
Fault phenomenon 3: A vintage Toshiba laptop, when the external LQ-1600K narrow row printer prints the document, the print is abnormal, and the print is often stopped. Machine configuration: Pentium 166, 16MB memory, 2.1GB hard drive, built-in 16x optical drive, operating system is Windows 95.
Fault Solution: First troubleshoot the driver, and confirm that the Windows 95 system has no problem, the printer and print cable are intact. Set the printer to print quickly, the fault is still.
View the BIOS, the mode of the discovery is set to EPP, I / O address, and interrupt settings, and the printer also supports EPP parallel port. Helpless, holding the idea of trying, change the parallel mode to spp, print again, everything is normal!
* Analysis and Summary *
The setting of the parallel port includes two aspects: one side refers to the I / O address of the consolid port (address) and interrupt (IRQ); on the other hand, the parallel port is mode (MODE). In practical applications, everyone pays more attention to I / O addresses and interruptions, but often ignores the pattern settings. This is easily caused in the system that looks "all normal" systems, the printer and other peripherals have a strange fault.
Talking about the mode settings, the current parallel port mode is mainly as follows: 1. SPP, the Standard Parallel Port, the standard parallel port. This is the initial parallel port mode, now almost all parallel peripherals support this mode. 2. EPP, ENHANCED Parallel Port, enhanced high-speed parallel port. This is a new parallel model developed on the basis of SPP, and it is also the most used parallel port mode. Most printers on the current market, scanners can be two-way communications with PCs, support EPP mode. EPP is divided into two modes of EPP 1.7 and EPP 1.9, fault two description, which mode is selected depends on specific practices, because there are some printers or scanners not clearly indicated which mode of applicable, even specified, should also Verify in practice. 3. ECP, Extended Capability Port, the expansion function parallel port. This can be regarded as the most advanced parallel port mode, but the mode needs to be set to set the DMA channel, which consumes resources and can cause conflicts. At the same time, there are very few peripherals that support ECP, so in general, do not select this mode. In addition to the above three modes, there are other parallel port modes, such as Bi-Directional, etc., because there is less, here is not described in detail. In addition, some BIOS allows for use in one of two modes, such as "ECP SPP", "ECP EPP", etc. For such settings, it should also be selected by practice, just like a fault. In particular, the author discovered that some laptops used an EPP mode external printer, it is easy to happen to a problem with the fault three, so it is recommended that everyone will set the parallel port mode of the laptop to SPP.
