I don't often know the answers round here, but this time, like Unknown K, I do.
A stock 840av certainly can't do it, but the 840av will indeed record 30fps @ 640x480 — using hardware specifically designed to complement its native AV circuitry. One such piece of hardware is indeed the SpigotPower AV nubus card, one of a small number of cards designed for the unique DAV slot on the AV Macs.
I quote from some online source or other that came up while googling:
"SpigotPower AV Q&A
Q: What is SpigotPower AV, and with which Macs is it compatible?
A: SpigotPower AV is a video data compression/decompression card that is compatible with the Centris/Quadra 660AV and Quadra 840AV when using the Spigot AV 1.1 software (or the Spigot AV 1.1.1 software, not yet released as of this update) and QuickTime 2.0. It is also supported with the Power Mac 7100AV and 8100AV when using the SpigotPower AV 1.0 software and QuickTime 1.6.2. There is insufficient space in the Power Mac 6100 AV to install SpigotPower AV. SpigotPower AV compresses the data on the way in to get it down to a manageable level and decompresses it on the way back out. The result is smooth, 30 frames per second, 60-field video. SpigotPower AV is not recommended for use on Power Mac AV systems with QuickTime 2.0. Users may find that using either the Spigot AV 1.1 or 1.1.1 software with QuickTime 2.0 on PowerMac Systems may adequately meet their needs, but these configurations will remain unsupported. "
**
In fact, the cards were crap in the early ppcs, despite what the manufacturer's blurb says here, and they worked well only in the Quadras and Centris AV Macs.
I have one of these cards in my 840av. I run it under MacOS 8.1, with a later revision of the software (a Japanese developer updated the software after the US manufacturer went belly-up), and a higher Quicktime version, all with no trouble. I'd run it stock, under System 7 Pro, were it not for the fact that OS8.1 allows me to run a 2 x 9GB ultra-wide SCSI RAID (HFS+) in the machine, for 18GB of storage, controlled by a Nubus Jackhammer card.
A Quadra 840av can record full-frame video rather well in this configuration, and stack up a sizable Quicktime file without coughing. It was designed to have such "extreme" capability (for the time) by way of the installation of niche expansion options, and its nubus slots were especially speeded up to allow for maximum throughput for such usage.
Your 840av is "king of the Quadras" for reasons that relate to more than merely its 40MHz 68040 — but you'll need some add-ons. Now if only it had a proper L2 cache....
A stock 840av certainly can't do it, but the 840av will indeed record 30fps @ 640x480 — using hardware specifically designed to complement its native AV circuitry. One such piece of hardware is indeed the SpigotPower AV nubus card, one of a small number of cards designed for the unique DAV slot on the AV Macs.
I quote from some online source or other that came up while googling:
"SpigotPower AV Q&A
Q: What is SpigotPower AV, and with which Macs is it compatible?
A: SpigotPower AV is a video data compression/decompression card that is compatible with the Centris/Quadra 660AV and Quadra 840AV when using the Spigot AV 1.1 software (or the Spigot AV 1.1.1 software, not yet released as of this update) and QuickTime 2.0. It is also supported with the Power Mac 7100AV and 8100AV when using the SpigotPower AV 1.0 software and QuickTime 1.6.2. There is insufficient space in the Power Mac 6100 AV to install SpigotPower AV. SpigotPower AV compresses the data on the way in to get it down to a manageable level and decompresses it on the way back out. The result is smooth, 30 frames per second, 60-field video. SpigotPower AV is not recommended for use on Power Mac AV systems with QuickTime 2.0. Users may find that using either the Spigot AV 1.1 or 1.1.1 software with QuickTime 2.0 on PowerMac Systems may adequately meet their needs, but these configurations will remain unsupported. "
**
In fact, the cards were crap in the early ppcs, despite what the manufacturer's blurb says here, and they worked well only in the Quadras and Centris AV Macs.
I have one of these cards in my 840av. I run it under MacOS 8.1, with a later revision of the software (a Japanese developer updated the software after the US manufacturer went belly-up), and a higher Quicktime version, all with no trouble. I'd run it stock, under System 7 Pro, were it not for the fact that OS8.1 allows me to run a 2 x 9GB ultra-wide SCSI RAID (HFS+) in the machine, for 18GB of storage, controlled by a Nubus Jackhammer card.
A Quadra 840av can record full-frame video rather well in this configuration, and stack up a sizable Quicktime file without coughing. It was designed to have such "extreme" capability (for the time) by way of the installation of niche expansion options, and its nubus slots were especially speeded up to allow for maximum throughput for such usage.
Your 840av is "king of the Quadras" for reasons that relate to more than merely its 40MHz 68040 — but you'll need some add-ons. Now if only it had a proper L2 cache....