My newly-installed 10.2 gb hard drive seems to access data slowly. I sought help from the manufacturer’s website and one of the tests suggested was to check whether my operating system is DMA capable. My operating system is Windows 95 version 4.00.950B which is DMA capable. The website also suggested that I check if my hard drive is already DMA enabled. The trouble though is that the Windows Device Manager doesn’t show a ‘Resources’ tab for the hard disc drives, which (I think) is where the DMA check box should be. When I look for DMA channels in ‘System’ control panel > ‘Device Manager’ tab > ‘Computer’ there does not seem to be a DMA channel for either of my hard drives. How can I be sure whether or not my hard drives are DMA enabled and if they are not how can I enable them? Also, ever since I installed the new hard drive Scandisk has run at startup giving the message “There is an invalid long filename on this drive which Scandisk is unable to fix”. I have no idea what to do about this. What could be causing it?

For those who are interested, DMA stands for Direct Memory Access. Computer buses which support DMA allow data to be sent directly from a device to the computer’s memory. Normally, the data is sent to the CPU then to memory but DMA eliminates the ‘middle-man’ (being the CPU) which results in the CPU being freed from data transfer which speeds up the computer’s overall performance. Before starting the procedure to enable DMA, make sure that you have confirmed that your new hard drive and your existing motherboard are compatible with DMA. You should be able to do this by going to both the manufacturers websites or by contacting them. The setting to enable DMA is not on the ‘Resources’ tab in the hard drive properties window but in the ‘Settings’ tab. Go to the ‘Start’ menu > ‘Settings’ > ‘Control Panel’ and open the ‘System’ control panel. Click the ‘Device Manager’ tab and expand ‘Disk Drives’. Click on the hard drive for which you want to enable DMA (in Gordon’s case this would be the 10.2gb hard drive) and click the ‘Properties’ button at the bottom of the window. In the hard drive properties window which appears, click the ‘Settings’ tab. Under the ‘Options’ heading you should see a tick-box labelled ‘DMA’. If this box is ticked , DMA is already enabled on that hard drive but if it isn’t, click the box to tick it. Then press the ‘Ok’ button. You will now probably get an alert, warning you that enabling DMA may have undesirable effects on your computer. I am assuming that Gordon’s new hard drive and existing motherboard do support DMA as he consulted the manufactures website. To then enable DMA on the hard drive click ‘Ok’. At this stage it is still possible to back out. If you wish to do this, click ‘Cancel’. If you chose ‘Ok’ then you will be prompted to restart your computer. Click ‘Yes’. If your hard drive does support DMA you should restart with no problems. However, if something does go wrong and your hardware doesn’t support DMA then you will have to restart Windows in Safe Mode to disable it. If this scenario does occur, you can start Windows in Safe Mode by pressing the F8 key when you see the message ‘Windows 95 is Starting…’ just before the Windows splash screen appears during boot up. The Windows boot menu will appear and from here select ‘Safe Mode’. Follow the same procedure to disable DMA as you completed above to enable DMA except uncheck the box labelled ‘DMA’. However, in the event that you don’t even see the ‘DMA’ option in your hard drives settings, the above explanation will be lost on you. In that case have a look at www.pureperformance.com/9x/hd/hd11.htm. This explains how to enable DMA access using a different procedure to the one which I explained. Be warned though, I have not tested the procedure at the above URL so I cannot say if it works or has any undesirable effects on your computer. Regarding your Scandisk problem, Mix O. also sent in basically the same question as Gordon and I will answer the question in next weeks column after I have researched it more.