ZX Pilot #39 11 октября 2000

Железо

Iron - Answers to questions posed by superzvukovoy card for Speccy - DMA UltraSound Card.

               D M A U S C



(C) HARD



   Answers to the questions posed by superzvukovoy card for 
Speccy - DMA UltraSound Card. 


   "Play. Mod is an interrupt, real-time in percent DMA takes 
1000 cycles for INT (9000 peak)." What is this peak?


   The peak load is when player
busy calculating the parameters of the sample (note).
All calculations take an average of 7000 to
9000 cycles. At other times, when playing already  
sample; spent about 1000 cycles. This applies

increasingly play files of type
. Mod,. Mid, etc. When playing a simple
digitized sounds. wav,. voc,. pat, etc
this value is constant and express
Peak areas do not contain. Hopefully, this
all clear.


   That of the DMA circuit must be excluded to
It was just pure sound card without
accelerator (in the future, it dosobirat, but now a little bit 
to reduce costs)? 

   For clarity, I'll tell you what parts of the DMA, in fact, 
consists of: 

   a) The analog part (block DAC). Consists
from improved SOUND DRIVE. In
Basically, this device has and will play
but he differs little from the 4-channel COVOX'a, except that 
the volume of playback can be set from 0 to 63 and sound better.


   b) The digital part. She, in turn,
consists of several subchastey.

   - Power controller DMA. Here is to
[Article beaten in original]