Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: analogkid on January 02, 2005, 12:15:27 PM
-
hi,
my Toccata produces noisy sound when playing AIFFs from the scsi harddrive (GForce 040 Onboard-SCSI, GuruROM 6.9) if DMA is activated. If it's deactivated, the sound is ok. I've tried the HardInt Patch from the AHI Homepage, but it seems that the patched toccata.library doesn't work with AHI anymore. Has anybody a solution for this problem ?
My system:
Amiga 2000 Rev. 4.3
G-Force 040/33 MHz 16 MB RAM, onboard SCSI, GuruROM 6.9
4,3 GByte SCSI-Drive
Teac CD-R55S
Picasso II
VLab Y/C
Connexion
Toccata
Algor USB
---
There's a truth in the madness I can't get beyond
-
@analogkid:
What version of AHI are you using?
/Patrik
-
I've tried the old AHI 4 and latest AHI 5, same result.
-
Hi patrik
do you know if the DMA enabled, drain more power from the PSU?
-
@analogkid:
The problem is most likely that the GVP SCSI-controller locks the bus for a too long continuous time when doing DMA-transfers thus preventing the Toccata from being fed with sound data often enough.
There was a utility called GvpPatch that could reduce the size of the DMA-transfers, effectively reducing the "bus-hogging" tendency of the GVP SCSI-controller.
@Framiga:
DMA transfers should not require any extra power. And if it would cause fluctations in the power, it would make the computer unstable.
/Patrik
-
I think you mean the GVPSCSICtrl CHUNKSIZE Option, for the SerialPatch. I've tried this, with very low and very high settings and the with the default setting, but nothing helped.
-
@analogkid:
There actually is a GVPPatch utility, check this (http://www.lysator.liu.se/amiga/ar/guide/ar226.guide?MAD_040SCSI) link (just search for "GVPPatch").
As far as I know, up to version 1.7 was released and existed in the biz/patch directory as GVPPatch17.lha on Aminet, but for some wierd reason it is missing nowadays. Anyhow, you can find v1.5 and and a rather good readme describing it on this (http://www.gvp-m.com/gvpio1.dms) disk. You can also find v1.6 on this (http://ftp.back2roots.org/back2roots/cds/lsd/legal_tools/LSDlt043.DMS) disk. As you have a GuruROM it shouldn't help, but there is no harm in giving it a shot :).
/Patrik