OpenEuphoria

1. [OT] sdram info needed

• Posted by gertie at visionsix.com Mar 27, 2003
• 336 views

Does anyone have a schematic on how to make a commonly available 
generic dimm sdram/edo look like a plain olde static ram? With 3gigs of 
data, at 60ns/access/byte, it will take 3 minutes to bruteforce search it, and 
obviously using software on top of an OS will take considerably longer. I am 
thinking of reviving a 20yr old idea, which wasn't useable back when dram 
came in 16Kx1 chips and was $1500/megabyte. But to make it work, i need 
to use the mass produced and much cheaper computer memory forms, 
which i am lacking info on. Online references or available book sources 
welcome.

Unless someone has 10,000's of 3 to 10 gigs of the olde dip chips they want 
to get rid of?

Thanks,
Kat

3. Re: [OT] sdram info needed

• Posted by gertie at visionsix.com Mar 27, 2003
• 321 views

On 27 Mar 2003, at 14:11, Evan Marshall wrote:

> 
> Don't know if this helps, but.....
> http://www.micron.com/products/datasheet.jsp?path=/DRAM/EDO+FPM

Not really, every chip is marked "not recommended for new designs", 
meaning it is slated for being discontinued. Plus, those are chips, not readily 
available simms or dimms. The tsop package is nearly impossible for the 
home hobbyist to solder into a design, the soj is even worse since they will 
wick solder under the package, and i'd hate to try doing gigabytes of them 
one megaBIT (at 50pins each) at a time. There's no typical application 
schematics either, if i could drop in a refresh controller chip straight out of 
such literature, that would save me design time too.

<rant>
And doncha love how the dimm sellers will market the module as a 20ns or 
faster dimm, but the part company like Micron plainly shows the *total* read 
cycle time (excluding time out for refresh) is 80ns? I've seen "200mhz" ram 
that couldn't keep up with a generic fpga if put to the test. Reminds me of 
16mhz 8085's that couldn't keep up with a 1mhz 6502.
</rant>

Kat

 
> gertie at visionsix.com wrote:
> 
> >
> >On 27 Mar 2003, at 10:12, rudy toews wrote:
> >
> >  
> >>gertie at visionsix.com wrote:
> >>    
> >>
> >>>Does anyone have a schematic on how to make a commonly available 
> >>>generic dimm sdram/edo look like a plain olde static ram? With 3gigs of
> >>>data,
> >>>at 60ns/access/byte, it will take 3 minutes to bruteforce search it, and
> >>>obviously using software on top of an OS will take considerably longer. I
> >>>am
> >>>thinking of reviving a 20yr old idea, which wasn't useable back when dram
> >>>came in 16Kx1 chips and was $1500/megabyte. But to make it work, i need to
> >>>use the mass produced and much cheaper computer memory forms, which i am
> >>>lacking info on. Online references or available book sources welcome.
> >>>
> >>>Unless someone has 10,000's of 3 to 10 gigs of the olde dip chips they 
> >>>want 
> >>>to get rid of?
> >>>
> >>>Thanks,
> >>>Kat
> >>>
> >>>
> >>hi Kat
> >>now i am curious.  i think i still have some old manuals for memory 
> >>boards. i started computing with an S100 system (cromemco)(pre-ibm pc) 
> >>and had added a 'ram drive' to it. is that your project?
> >>i had bought the ram drive already assembled.
> >>    
> >>
> >I remember the S100 stuff, but i never had one myself. I did have a ZX80,
> >VIc20
> >and C64. The C64 still works fine. I have books on chips like the 6116, and
> >others of that era. For massive memory those chips are still far too
> >expensive,
> >in parts cost and assembly time and power use. I expect i will be using the
> >smallest simm or dimm modules i can reasonably get. I am more interested in
> >width than depth of the memory. I don't have books on the simms or dimms, or
> >application notes and gotchas.
> >
> >Kat

5. Re: [OT] sdram info needed

• Posted by euman at bellsouth.net Mar 27, 2003
• 318 views

{{{ This is one very large guess where you could pickup as many of these chips as you want. I remember when I was in the U.S Military (back when) they (on every base) have a surplus depot of old stuff (almost like a junk yard, if you will) that has huge antique IBM Servers and stuff they couldnt sell to the public at auction. I'll almost bet $100 you could get all you need in Pensacola, Fl. (I think this is the nearest site to you, maybe not) Try it out and see what you come up with. (longshot) they will probably load the stuff in a truck for you just to get rid of it.

Euman

--- Original Message From: <gertie at visionsix.com>

7. Re: [OT] sdram info needed

• Posted by Evan Marshall <1evan at sbcglobal.net> Mar 28, 2003
• 328 views

Micron sells these as generic memory through their Crucial Technology 
division.
www.crucial.com
They conform to the JEDEC standard.  http://www.jedec.org/default.cfm
The modules page has downloadable data sheets in pdf form with timing charts

gertie at visionsix.com wrote:

>
>On 27 Mar 2003, at 15:26, Evan Marshall wrote:
>
>  
>>Well, here are modules, still no schematics though, sorry.
>>http://www.micron.com/products/datasheet.jsp?path=/Modules
>>    
>>
>There ya go !! Now, to find timing sheets, but i know where to start now. Do 
>you know how generic these are for general purpose computer sdram? Are 
>they going to be proprietary to Micron, or will PNY, MGV, Centon, etc be the 
>same?
>
>Kat
> 
>
>
>
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