[Coco] any interest in an 8MB ram card for COCO3?

[Gene Heskett]

On Friday 16 April 2010, Aaron Wolfe wrote:
>Out of curiosity, aside from a ram disk, what else can be done with
>this extra ram?
>
>I ask because if a ram disk is the only useful application, perhaps
>presenting it as ram in the system is the wrong approach.  Maybe it
>would be more useful presented as a disk device.
>
>-Aaron
>
Generally it is Aaron.  I wouldn't mind getting my hands on one of those, 
which if  it was non-volatile would be ideal.  Depending on how it interfaces 
with the gime chip, it might be possible to modify myram to control it too.

As it is, I have a distop 2 meg kit in mine, and I wrote a ramdisk called 
myram.dr, uses ./r0.dd as the descriptor, both of which can be built into the 
os9boot file.  It has the ability to be made any size you want up to stealing 
system memory, which I don't believe the system's malloc stuff will allow.

Its size is set by the number of tracks in the descriptor, with each 'track' 
(cyl to dmode) representing an 8k block of ram.  Any access to it checks to 
see if its formatted, and formats it in a fraction of a second if not, so 
dmodeing the cyl value before it has been accessed to whatever size you want, 
then any other access formats it, even copying a file to the unformatted 
ramdisk is sufficient, it will be formatted before the copy can proceed.

Its speed is the same as that of any scsi drive attached, and I have used it 
at sizes up to around 1.6 megs on my 2 meg machine.

>On Thu, Apr 15, 2010 at 6:52 PM, Stephen Adolph <twospruces at gmail.com> 
wrote:
>> My understanding from the cocozilla site was-
>>
>> *  the locations in upper memory that are defined, can be extended to 2MB
>> *  additional memory locations can be used to extend memory further
>>
>> SRAM is not a great choice for enormous amounts of ram.  DRAM is better.
>> Perhaps 2MB is the sweet spot, given I have 1MB and 2MB SRAMs.
>>
>> ..Steve
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>
>--
>Coco mailing list
>Coco at maltedmedia.com
>http://five.pairlist.net/mailman/listinfo/coco
>


-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My opinions may have changed, but not the fact that I am right.