[NTLK] eMate 300 Memory Upgrade

[Randy Glenn]

Also, does anyone have the eMate diagnostic PC card? That will probably be
useful for testing whatever card we wind up with.

On Wed, Apr 4, 2018 at 10:29 PM, Randy Glenn <randy.glenn at gmail.com> wrote:

> A larger part might work. From the research I was doing yesterday, the RAM
> chips used in the eMate card have 12 row address bits and 8 column address
> bits, with the lower 8 row bits sharing pins with the column bits. Two
> strobe signals are used to indicate whether the address present is a row or
> column address. A part with 12 or more row bits and 8 or more column bits
> might work - the problem with an exact replacement is that the 1Mx16 chips
> I found still being sold, all use 10 row and 10 column address bits. I
> don't think the eMate will be able to see all of that memory.
>
> If you have a schematic in that ZIP file that you're willing to share, I
> can start checking into alternatives.
>
> On Wed, Apr 4, 2018 at 7:02 PM, NewtonTalk <newtontalk at pda-soft.de> wrote:
>
>> > Duplicating the layout is probably not a huge problem these days - it's
>> locating compatible RAM and Flash memory. I don't think that stuff has
>> been
>> made in about a decade and a half.
>>
>> Folks, hold your horses for a while. As I recently mentioned on the list,
>> I've bought everything David had left from his SER001 and his eMate
>> upgrade
>> board projects.
>>
>> David also kindly mailed me a zip file that, as far as I can judge it,
>> contains everything I'd need for having new PCBs made. I can't open most
>> of
>> these files, but that's not surprising since I do not have any PCB
>> software
>> on my computer yet. But there are folders named Gerber, Plot, PCB etc. So
>> I'm inclined to think that as to having new boards made, I already have
>> what
>> is required.
>>
>> You probably can't believe this, but my life has been so busy recently
>> that
>> David's box has been sitting on my desk for weeks. So I don't know yet
>> what's in there. I think David mentioned unpopulated boards. I could use
>> those to rig up a 2nd edition prototype. The eMate memory upgrade
>> basically
>> consists of three memory chips. You can buy memory chips today. Most
>> likely
>> not those needed for the board, but so what. The chips you CAN buy will
>> provide much more memory than the original chips and have more pins.
>> However, as long as voltage, current and timing are similar, which they
>> very
>> often are, all it depends on is the pinout. You can easily turn a 16MB RAM
>> into a 4MB RAM by bending two address pins up and wiring them to ground.
>> The
>> eMate wouldn't know it's working with a chip whose memory size we just
>> shrunk (Honey, I shrunk the chips...).
>>
>> Once everything works, we can adjust the data files I have from David and
>> have new boards made.
>>
>> Cheers
>>
>> Frank
>>
>> -- Newton software and hardware at http://www.pda-soft.de
>>
>>
>> ----------------------------------------------------------------------
>>
>> http://newtontalk.net/
>> http://twitter.com/newtontalk
>>
>
>