[comp.sys.mac] Tough Ramdisk?

jorice@cs.tcd.ie (The Lone Biker of the Apocalypse) (01/09/89)

I was doing some programming on Amigas recently and the only thing that kept
me from going insane was a really nice Ramdisk that survived resets. I would
really, really like something similarly tough for the Mac. Y'see, I'm using
Lightspeed C 3.01 from floppies and turnaround time is less than stunning.
I'd like to compile to ram, or put Lightspeed itself there, or something,
depending on memory limitations. I'm currently working on a 1M Mac+, but I
may be expanding this. So, anyone know of a Ramdisk that survives DS errors,
generally, and, ideally, is size-configurable?

bob@accuvax.nwu.edu (Bob Hablutzel) (01/10/89)

> I was doing some programming on Amigas recently and the only thing that kept
> me from going insane was a really nice Ramdisk that survived resets. I would
> really, really like something similarly tough for the Mac. Y'see, I'm using
> Lightspeed C 3.01 from floppies and turnaround time is less than stunning.
> I'd like to compile to ram, or put Lightspeed itself there, or something,
> depending on memory limitations. I'm currently working on a 1M Mac+, but I
> may be expanding this. So, anyone know of a Ramdisk that survives DS errors,
> generally, and, ideally, is size-configurable?

I doubt this can be done with the Mac except with dedicated external hardware.
The problem is that the top of memory mark is reset at each startup, to the
physical top of memory. The RAM disk would have no control over the possible
overwritting of it's data before the RAM disk INIT executed.

On the external hardware side, it would be fairly easy. Matter of fact, I
remember a Q-Bus board (for PDP-11/x3 machines) which emulated RX01 drives
with bubble memory. This gained you a persistant drive at bubble memory 
speeds. (Note - bubble memory is considerably slower than memory we're used
to, at least the last time I looked). No recollection about the speed/price/
manufacturer. And no idea if a similar puppy exists for the Mac.

Bob Hablutzel	BOB@NUACC.ACNS.NWU.EDU

kent@lloyd.camex.uucp (Kent Borg) (01/11/89)

If you are looking for an external hardware ram disk, there once was
(still is?)  one that went by the name Dasch (I think I have that
right...).  I think I was hearing about it around a year+ ago.

I think it was in the 1/2 to 1 meg region--not exactly gigantic but
will hold a disciplined System folder.

If this is no longer made, maybe the used market?

Good luck.


Kent Borg
kent@lloyd.uucp
or
hscfvax!lloyd!kent