Re: Fat40 RAM problem?

From: A. Fachat <afachat_at_gmx.de>
Date: Sun, 31 Aug 2014 19:19:22 +0200
Message-ID: <1482d1409a8.279a.b4d1f2b66006003a6acd9b1a7b71c3b1@gmx.de>
I think I misinterpreted the first measurements. Because of the indirect 
indexed access ($11),Y there were two accesses. In the first measurement I 
only saw the first read but interpreted it as the write access. I found 
that out when I later checked the r/-w line.
So no bus conflict.

André


Am 31. August 2014 18:39:58 schrieb Gerrit Heitsch <gerrit@laosinh.s.bawue.de>:

> On 08/31/2014 05:51 PM, A. Fachat wrote:
> > On Sunday 31 August 2014 16:14:34 you wrote:
> >> Hi,
> >>
> >> So if it is not the RAM, what could happen in the driver - probably UE9 or
> >> UE10 here
> >> http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/univ/8032081
> >> -05.gif that causes this? Probably a slight delay in switching the line on
> >> or off?
> >
> > Nope. Got it. It in fact was the RAM itself.
> >
> > Replaced the UE9 and UE10 74LS244 buffers to no avail, still not full memory.
> >
> > Then replaced the UA16 RAM - there you go, full memory!
>
> Learn something new every day... I didn't think that a 4116 DRAM would
> be able to 'win' against an LS-TTL driver.
>
>   Gerrit
>
>
>
>        Message was sent through the cbm-hackers mailing list



       Message was sent through the cbm-hackers mailing list
Received on 2014-08-31 18:00:02

Archive generated by hypermail 2.2.0.