info-vax@ucbvax.ARPA (03/16/85)
From: KField@BBNG You may want to contact Digital Sound Corporation (Santa Barbara, CA) at 805-963-8951. Their DSC-200 Audio Data Conversion System digitizes at 16 bits/sample, and is spec'd for sampling frequencies up to 20 kHz. I believe that I heard that they were joint- marketing it with DEC, so I'm surprised that your salesman didn't tell you about it. -Ken Field
info-vax@ucbvax.ARPA (03/18/85)
From: Michael Cohen <mth135%BOSTONU.bitnet@WISCVM.ARPA> ----- I was wondering if anybody can recommend a set of A/D converters with a real time sampling clock which can be interfaced with little work to a VAX 11/730. We were originally going to purchase a DEC LPA-11F DMA controller for lab devices, but the device was dropped by DEC apparently when the new FCC regulations came out. My salesman informed me than no more of these devices are available from digital. The application is to digitize audio signals (sampling freq from 5 - 15 kiloherz) so we can analyze them for purposes of speech recognition and perception. I would appreciate it if someone who know of a LPA-11F for a VAX 11/730 or a similiar device from another vendor to let me know where they are available. I will post the list to info-vax if there is much interest. -----
info-vax@ucbvax.ARPA (03/22/85)
From: Jorgen_Pihl%QZCOM.MAILNET@MIT-MULTICS.ARPA The 730 is a Unibus machine, so there are several options. If you want to go the DEC way, you could use an ADF01 300 kHz 12 bit converter. Or you could order a system from Data Translation, with 12 or even 16 bits resolution, at 100 kHz. Note that you need a DMA interface.Not even RSX is happy with 7000 interrupts per second, and VMS would be even unhappier. The DMA should also have multiple buffers, in order to avoid gaps in the A/D sampling. The LPA was (is) certainly a wounderful unit. I have it on two RSX systems. It samples data at 150 kHz with very little noticable CPU load.