CompuServe Messages

Steve, There's a program you may want to check out over on the Zenith Data Systems Forum (GO ZENITH) Section 5 – DOS Utilities. Here's the abstract: .. [76703,662] Lib: 5 .. CDTA.ZIP/Bin Bytes: 14661, Count: 206, 06-Nov-92 .. .. Title : CDTA diagnostics and tests for CD-ROM drives .. Keywords: UTILITY CD-ROM CDROM TIMING ANALYSIS DIAGNOSTICS SPEED TESTS .. .. CDTA is a "CD-ROM Timing Analyzer." It measures data throughput of a .. CD-ROM drive/controller and estimates access time. Those numbers should .. prove useful in comparing CD-ROM drives for speed. CDTA also tests CD-ROM .. drives, controllers, and disks for diagnosis in the event of problems. .. Free. I've used it and it's a good clean program that seems to work as advertised. >>Anyway, it would be nice to know what I'm giving up by not trying harder to get DMA access to work.<< I still maintain that for this type of testing – all the CPU is doing is processing CD-ROM activity – interrupt driven software reads are just as fast as DMA. In fact, Richard L Shorter 71740,156 makes a good argument for why they are FASTER than DMA. But that is for a situation where the processor doesn't have much else to do. In theory, when you get into a Multimedia type situation where all sorts of things are happening as close to "at once" as possible (video updates, CD-ROM reads, sound, etc.) and the system is pushed near the limit, letting the DMA handle the CD-ROM transfer should increase system throughput. I'm still looking for a definitive test to prove or disprove this idea. It's late. I gotta put away my soapbox and go to bed. Good Luck. Ken