Talk:Macintosh Quadra 840AV

DSP primarily for supporting Plaintalk speech recognition?
I always had thought that the DSP was basically only included on the Quadra and Centris lines because Plaintalk used it.. I know that there was the complicated and (at least I thought at the time - although I was only 15 :) very cool ARTA architecture for doing your own things with it. But was there ever any official press release to the effect that the DSP was only there to make Plaintalk able to work - or be able to work in the background? Could PT work on systems without the DSP?

Jimw338 (talk) 02:07, 8 February 2012 (UTC)


 * My understanding is that it potentially allowed for realtime audio processing, hard disc recording, and TV/computer video overlay, as per the Video Toaster. The problem, judging by this forum thread, is that in a fashion typical for Apple at the time the company appeared to have just dumped the DSP into the machine without liaising with developers or making the tools freely available. A similar problem dogged the Macintosh IIfx and A/ROSE (for example). Certain versions of Photoshop with the appropriate drivers used the DSP, but only for a small number of operations; beyond that you would need to go back to 1994 or learn how to program the DSP in assembly language to get the most out of it. -Ashley Pomeroy (talk) 14:50, 1 July 2018 (UTC)

PowerPC Upgrade, Mac OS 9.1 Not possible
The infobox lists the Quadro 840AV as having the capability of running Mac OS 9.1.

This is quite impossible: The Power Macintosh upgrade card, requires a MC68040 processor direct slot (PDS) which the Quadra 840AV does not have. or a LC PDS or a IIci cache slot.

Secondly, the infobox says that the computer has 8MB of memory on the motherboard, and is expandable to 128MB of memory, when if you add 4x32MB 72pin SIMMS gives you a total of 136MB of ram.

This is the question that was asked: https://www.betaarchive.com/forum/viewtopic.php?f=64&t=42696 and this was the answer:

"Hardware Requirements

Apple Macintosh Centris 610, 650 or Quadra 610, 650, 700, 800, 900, 950 (Centris 610 and Quadra 610 require an adapter and will only work with the 100 MHz version of the PowerPro 601)"

https://lowendmac.com/2016/the-unofficial-powerpro-homepage/


 * Agreed - the Quadra 840av isn't supported by available PPC upgrades because it doesn't have a PDS slot. I've made the change. But the RAM section looks OK. Perhaps someone already fixed it. It doesn't say 8MB onboard, just 8MB, which will have been a SIMM.
 * Phipli - 08:57, 13 October 2022 (GMT) — Preceding unsigned comment added by 86.158.75.239 (talk)

Power Supply
"the housing, chassis, power supply, and internal storage assemblies are the same"

I recently repaired two 840avs to working order. The power supply is not the same as a quadra 800. The connector, size, and specs are different. It is quite similar to the power macintosh 9500 and 8500's power supply, which can be used in an 840av. The quadra 800's power supply is compatible with older machines such as the quadra 700, anything in the IIvx style (including PM7100), and IIci/IIcx. 2601:603:1081:BCB0:B44B:909:4EB5:9FFD (talk) 00:23, 30 January 2024 (UTC)