EPROM emulator

[steve ravet]

"Andrew K. Mattei" wrote:
> 
> steve ravet wrote:
> >
> > Did some more looking around.  IDT (www.idt.com) makes DP RAMs also.
> > They have them in 32kx8 and 64kx8, in PGA and PLCC packages which are
> > actually usable.  Part numbers are 7007 (32k) and 7008 (64k).  Cypress
> 
> Woosh... thunk... THUD!
> 
> What was that sound? It's the sound of my head being hit by a cone
> shaped hat. I threw away (yes) some idt 7005's (8k) last week that were
> attached to some blown up equipment. "Had no use for 'em". Would've made
> good "prototyping on the cheap" chips. Dangit, I never throw anything
> away... Dangit, dangit, dangit. Maybe I'll find some more...

I know the feeling...  A place I used to work was great for just picking
up "old stuff" lying out in the halls.  I left a lot behind when I
quit...

The 32K part is the only one available in PLCC, from either cypress or
IDT.  So, that's probably as big as we can go.  We could put two of the
down for 64K.  Not as 2 switchable banks, but as one big 64K bank.

> 
> >
> > Let's try a flash PIC part, they're cheaper because they're not in a UV
> > erasable package.  16f874 and 16f877 look like good parts:  5 I/O ports
> 
> Sounds logical to me. Would the CCS compiler (http://ccsinfo.com) work
> on those processors? That would be really cool if it did. I like
> programming in C, and would absolutely love to do a PIC that way. ;) I
> didn't see it in the "supported devices" list, though.

I know there is a C compiler for a PIC, but honestly, given the limited
amount of memory and stuff, I think it'd be better to do it in
assembly.  It's a very simple architecture, and only 30 instructions or
so.

> 
> >
> > I'm working on a schematic to illustrate it....
> 
> I look forward to seeing it.

-- 
Steve Ravet
steve.ravet at arm.com
Advanced Risc Machines, Inc.
www.arm.com