PDA

View Full Version : CD ROM DMA for CD-R?



18-07-2001, 06:17 PM
I have installed a HP 9140i CD-R(4X, 8X, 32X). I deliberately left my Mitsumi FX 240 (24x) so that I could read from the CD ROM and record to the HP at the same time.
This worked on a data CD, but the only way I can get audio CDs written is by copying them to the hard drive first. I have tried all speeds on the HP including 2X.
HP has DMA enabled (as recommended): should I enable DMA for the Mitsumi? Win 98 has the HP and Mitsumi sharing IRQ 15. Should I enable DMA for the HDD?
I have a K6-2 366, 64Mb Ram, running Win98 Se, and a Seagate 20Gb HDD

18-07-2001, 08:06 PM
DMA enabled where ever possiable, otherwise you will suffer a rather big performance drop.

18-07-2001, 08:17 PM
For starters i wouldn't recomend doing on the fly copying with ide drives, especially if they are on the same channel which they are as have the same IRQ. IDE can't use two devices being used at once and has to switch between them, which tends to cause buffer underruns (coasters).
Regarding DMA mode, it depends on the drive, turn it on for the HDD, but as for the CD drives it depends, try turning it off on both drives.
It will work with it turned off but will use more of the processor.
As for the audio cds not copying on the fly, my guess would be that the cdrom is too slow at reading the audio digitally, your cd-rw will probably be much faster at reading them anyway.

20-07-2001, 05:46 PM
I have a 12x8x32x CD-R/RW drive and 52x CD-ROM on the same ide channel (in my P200, with 64MB RAM), i do on the fly copying at 12x (mostly because of a lack of hard drive space), and have never had a buffer underrun error.