[sdiy] TC5514 polysix memory...upgrade?

[Bob Weigel]

The problem would be in storage.  Each time you do a memory write with 
an 8 bit data line you have to have 8 bits of something to read.  So you 
would just be contaiminating the 4 bits you aren't currently trying to 
address when you write since there are only 4 bits at a time available 
on the data buss..unless you do some intelligent buffer subsystem :-).  
READING it would work fine.   Of course it's just a lot of work since 
there are 4 bit chips out there that are already organized to allow me 
to simply switch a couple addy lines to access much more memory.  I just 
wanted to see if someone knew for sure whether the timing specs on the 
TC5514 and so on are equiv. to another chip with more address lines 
basically.  -Bob

dragon.servicing wrote:

> Hi,
> just a quick idea but how about using an 8 bit chip, and then having 
> some logic to switch  between the two sets of four data lines.
> this would give you double the number of memories.
> but of course there is probably a reason why this wouldn't work....
>
> regards Peter
>
> Bob Weigel wrote:
>
>> I have a ps6 that apparently has a dead one.  Can't store even when 
>> it's turned on.  All lines look like they are trying to do what is 
>> right.  Not a bad board at all.  But someone had put a Li battery 
>> which is not a good idea of course.  But wouldn't think it would lead 
>> to dead memory but who knows maybe someone zapped it when they were 
>> installing the battery.
>>
>> ANyway I was thinking it'd be cool to design even a simple daughter 
>> board that has leads for a switch that could be accessed somewhere 
>> non-intrusive that would give the ps6 more memory by switching a 
>> couple more address lines.  Does anyone know a compatible 4 bit data 
>> out chip that would pull this off with 16K or something? -Bob
>
>
>