RE: iec to pet

That is true, but it also incorrectly prevents a write enable pulse.
Conversely when RW is high (READ), both /OE and /WE are asserted. 

-----Original Message-----
From: owner-cbm-hackers@musoftware.de
[mailto:owner-cbm-hackers@musoftware.de] On Behalf Of David Wood
Sent: Friday, October 01, 2010 11:37 AM
To: cbm-hackers@musoftware.de
Subject: Re: iec to pet


It looks like u4 gate d prevents that.  Anding S02 with R/!W prevents OE
from being output if RW=0.

Am I reading the circuit wrong?


On Fri, 1 Oct 2010, Steve Gray wrote:

> Hi all,
>
> Sorry for the delay. I looked at what I'd drawn and realized it was a 
> little messy, so I've re-drawn it. Please excuse my sloppy drawing 
> skills. I need to learn one of the layout tools available and make a
proper one.
>
> So, for those interested, here is my hand-drawn CBM-II 24K RAM/EPROM 
> cartridge
> schematic:
> http://www.6502.org/users/sjgray/computer/cbm2/cbm2-24k-schematic.jpg
>
> You can see a picture of it on my CBM-II web page:
> http://www.6502.org/users/sjgray/computer/cbm2/index.html
>
> Thanks again to Ernie Chorny for lending me the cartridge!... Ernie, I 
> promise to get it back to you soon ;-)
>
> Steve
>
>  
> ----- Original Message ----
> > From: "Hoffmann-Vetter, Martin" <martinhv@arcor.de>
> > To: cbm-hackers@musoftware.de
> > Sent: Fri, September 24, 2010 7:06:51 PM
> > Subject: RE: iec to pet
> >
> > Hello,
> >
> > >>> I also reverse engineered the schematics for a 24K RAM cartridge
> > >>
> > >> I'm always interested in schematics.
> > >
> > > As am I!
> >
> > I'm interested, too!
> >
> > Greetings Martin
> >
> >
> >
> >       Message was sent through the cbm-hackers mailing list
> >
>
>
>        Message was sent through the cbm-hackers mailing list
>

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