[Coco] Bubble Memory

[Gene Heskett]

On Tuesday 15 August 2017 08:31:20 Bruce W. Calkins wrote:

> One of the limits to the CoCo 1 & 2 memory expansion was the inability
> to shift small-to-medium sized blocks in and out of the memory map.
> Basically it was limited to 32k mapping blocks.  This applied to the
> PBJ 128k & 256k expansions too.  That said; RAM Disks really did speed
> up many processes.
>
> Bruce W.

Debatable. I wrote a ramdisk that could use as much ram as the coco3 
could spare, with my 2 meg disto kit, that was about 1.7 megabytes.

As a storage/retrieval device its speed was limited to how fast the coco3 
could move data which was around 11 seconds a megabyte. Surprisingly. a 
long compile, such as rzsz-3.3.6, was no faster using myram as the 
scratchpad, than it was using the Maxtor 120 megabyte hard drive I was 
using at the time. Both were speed limited by the same speed limit, the 
coco3's ability to move the data. IOW, megaread was 11 seconds for 
either media.
>
> On 08/14/2017 11:13 PM, Carlos Camacho wrote:
> > I feel like it was just yesterday when I opened up TCCM and read
> > that 128KB bubble memory upgrade article for the CoCo. All I could
> > think of with my 16K was, "I'll be happy with a 32KB piggy back...
> > 128KB was insane...who in their mind would need so much memory?"
> >
> > Carlos Camacho

That was the last gasp of bubble memories life. Dram prices were falling  
like a rock, rotating media was getting faster, and even the 120 meg 
maxtor drive spent tied to a disto 4n1 spent a good share of its time 
waiting on the coco just a couple years later. I sure as tootin wasn't 
about to put any money into what was obviously a dead tech. IIRC 130 
megabytes of bubble would have cost in the thousands, if you could find 
it surplus. They never made enough to have a surplus to sell out was the 
impression I got at the time. :(

Cheers, Gene Heskett
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