taob@micor.ocunix.on.ca (Brian Tao) (06/15/91)
(It doesn't look like this message got out the first time, so here it is again... apologies if you've read this already!) For all the GS hardware types out there: how difficult would it be to patch in another 64K worth of RAM to the Ensoniq DOC? Can the memory softswitch on the DOC be used to "bank-switch" the extra RAM? Please don't remind me of how my warranty will magically disappear if I attempt any of this (I probably won't)... I just want to know if it is technically feasible. - Brian
gwyn@smoke.brl.mil (Doug Gwyn) (06/16/91)
In article <1991Jun15.031838.9787@micor.ocunix.on.ca> taob@micor.ocunix.on.ca (Brian Tao) writes: >I just want to know if it is technically feasible. Nope.
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) (06/17/91)
gwyn@smoke.brl.mil (Doug Gwyn) writes: >In article <1991Jun15.031838.9787@micor.ocunix.on.ca> taob@micor.ocunix.on.ca (Brian Tao) writes: >>I just want to know if it is technically feasible. >Nope. Gee, at least tell him why. A raw 'nope' is really unhelpful. It's technically feasible, although it is not something to try unless you know what you're doing. If no one does it over the summer then I might try it when I get back (I'll want my roommate's oscilloscope) and then I can give people cookbook instructions. In any case, it requires some permanent warranty killing modifications to the motherboard unless you want to invite disaster, so caveat usor. According to the schematics, all the signals are available (but you'll have to figure out which of the two unconnected DOC pins to use, and what -- if any -- timing requirements it has). Practically, however, it'd be a bitch unless you want to desolder the DRAMs and replace them with sockets (get nice machined ones that can be soldered to the motherboard on both sides). You'd also need a test clip or two to get the bank-select signals from the DOC and elsewhere. To figure out which DOC pin is being used as the bank select (I suspect that one of the unconnected DOC pins, probably "BS", is the bank select bit and that you can pick from two pairs of DRAMs with it), find an oscilloscope and write some test programs with the DOC (not for the squeamish) and watch the outputs while comparing them to known ones like the DOC's RAS and the GLU's CAS line. To hook up the real test setup, replace both DRAMs with machined sockets and make a test board that plugs into them and has room for four DRAMs (wire a pair of DRAMs to each socket in parallel, except for the CAS and OE lines which will probably need to be decoded according to which bank is being accessed). Use test clips to get the necessary signals from the DOC and elsewhere (you may have to use something cheesy like an announciator output if the Sound GLU bank bit is not available in the hardware (and it is a PLCC so attaching a jumper to it could be nasty in any case). It would be nice if the extra bank were enabled by the reserved bit in the Sound GLU, but don't count on it. The sound tools don't have any way to specify the extra bit anyway so you'd have to set it between DOC RAM loading calls or write your own sound software anyway. Todd Whitesel toddpw @ tybalt.caltech.edu
gwyn@smoke.brl.mil (Doug Gwyn) (06/17/91)
In article <1991Jun17.110401.7382@nntp-server.caltech.edu> toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes: >The sound tools don't have any way to specify the extra bit anyway >so you'd have to set it between DOC RAM loading calls or write your own sound >software anyway. I think the 16-bit address space assumption is so much wired into the GS sound subsystem that it makes any attempt to extend it infeasible except maybe for Apple, who are in a position to support such an extension.
sb@pnet91.cts.com (Stephen Brown) (06/18/91)
taob@micor.ocunix.on.ca (Brian Tao) writes: > > >(It doesn't look like this message got out the first time, so here it is >again... apologies if you've read this already!) > >For all the GS hardware types out there: how difficult would it be to patch in >another 64K worth of RAM to the Ensoniq DOC? Can the memory softswitch on the >DOC be used to "bank-switch" the extra RAM? Please don't remind me of how my >warranty will magically disappear if I attempt any of this (I probably >won't)... I just want to know if it is technically feasible. > >- Brian If the Ensoniq chip generates the high order address, then it's probably possible. I'll hack YOUR IIgs motherboard Brian, not mine. (I'm pretty good with a soldering iron, but for an extra software-UNsupported 64K of memory, I'm not doing the hack on MINE) +---------------------------------------------------------+ | Stephen Brown Toronto, Canada | | Internet: sb@pnet91.cts.com UUCP: utzoo!pnet91!sb | +---------------------------------------------------------+ | Apple II Forever !!! | +---------------------------------------------------------+ | Like my new .signature. ? Too bad. | +---------------------------------------------------------+
taob@micor.ocunix.on.ca (Brian Tao) (06/18/91)
From toddpw@nntp-server.caltech.edu (Todd P. Whitesel): > gwyn@smoke.brl.mil (Doug Gwyn) writes: > > >Nope. > > Gee, at least tell him why. A raw 'nope' is really unhelpful. Thank you, Todd. 8-) > It's technically feasible, although it is not something to try unless > you know what you're doing. I won't be the one doing the surgery on the GS, but your post will be forwarded to those who are interested in attempting this. > The sound tools don't have any way to specify the extra bit anyway > so you'd have to set it between DOC RAM loading calls or write your > own sound software anyway. None of the current crop of sound software will recognize the extra 64K of RAM anyway, and SoundSmith is the only application I can think of that would really benefit from it. Interesting to see how the DOC behaves with twice the RAM though...
andy@pro-palmtree.cts.com (Andy Stein) (06/18/91)
In-Reply-To: message from taob@micor.ocunix.on.ca
Well, there's someone named Harold Somethingorther on America Online
who figured out how to expand the Ensoniq's RAM to 128K, and he was going
to sell it as a package, but I think he decided not to. However, if you'd
like, I'll forward E-mail to him, and ask him if he'll give you the
instructions on how to do it. Remember, though, it'll be at your own risk.
This is probably highly unstable and may cause cumbustions or explosions,
or other nasty things that make your insurance skyrocket. :)asong@pro-nbs.cts.com (Andi Song) (06/19/91)
In-Reply-To: message from taob@micor.ocunix.on.ca
What would be the benefits of an extra 64K of RAM?
----
ProLine: asong@pro-nbs
Internet: asong@pro-nbs.cts.com
UUCP: crash!pro-nbs!asong
ARPA: crash!pro-nbs!asong@nosc.milandy@pro-palmtree.cts.com (Andy Stein) (06/20/91)
In-Reply-To: message from gwyn@smoke.brl.mil
It's certainly technically feasable. It's been done. The guy's just
not sure whether he'll be able to market it.taob@micor.ocunix.on.ca (Brian Tao) (06/22/91)
sb@pnet91.cts.com (Stephen Brown) writes: > If the Ensoniq chip generates the high order address, then it's probably > possible. I'll hack YOUR IIgs motherboard Brian, not mine. (I'm pretty good > with a soldering iron, but for an extra software-UNsupported 64K of memory, > I'm not doing the hack on MINE) Heh heh. Thanks, but no thanks, Stephen! I've already had a couple offers here to perform similar surgery to my GS. :)
taob@micor.ocunix.on.ca (Brian Tao) (06/22/91)
asong@pro-nbs.cts.com (Andi Song) writes: > In-Reply-To: message from taob@micor.ocunix.on.ca > > > What would be the benefits of an extra 64K of RAM? More room for instrument wave banks, for one thing. 64K isn't a whole lot if you want really nice sampled instruments. The best piano waveforms on some synths can occupy a meg of RAM (i.e., each key is sampled separately). The point is moot, however, since nothing currently supports 128K of Ensoniq RAM...
dzimmerman@gnh-tff.cts.com (Daniel Zimmerman) (06/22/91)
asong@pro-nbs.cts.com (Andi Song) writes: > In-Reply-To: message from taob@micor.ocunix.on.ca > > > What would be the benefits of an extra 64K of RAM? > ---- > ProLine: asong@pro-nbs > Internet: asong@pro-nbs.cts.com > UUCP: crash!pro-nbs!asong > ARPA: crash!pro-nbs!asong@nosc.mil Well, an extra 64k of DOC RAM, if it was supported by Apple, would allow more and larger waveforms to be loaded into DOC RAM.. This would allow loading of many complex SoundSmith instruments without compression, for example. It would also allow more of a digitized sound to be loaded into DOC RAM which would reduce the amount of time used to copy parts of the waveforms of digitized sounds into the DOC RAM. Basically, it would just make life easier for the Sound Tool Set and the Note Sequencer/Synthesizer tools. ------------------------------------------------------------------------------ Daniel M. Zimmerman InterNet - dzimmerman@gnh-tff.cts.com TFF Enterprises America Online - Surak TFF CompuServe - 76407,2246 "Learn reason above all. Learn clear thought; learn to know what is from what seems to be, and what you wish to be. This is the key to everything: the truth of reality, the reality of truth. What IS will set you free." - Surak Of Vulcan