15 Jun
2019
15 Jun
'19
6:33 p.m.
Hey Everyone,
I just thought I'd share a video of how I'm going about troubleshooting the
bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to do a
lot of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write them
up properly as well. I wasn't able to find a printset for the RAM card
itself, so I assume one doesn't exist in digital form yet. I have
documented what bit and memory range each DRAM on the card corresponds to,
which may help someone troubleshooting in the future
Regards,
Joe Zatarski
16 Jun
16 Jun
1:23 a.m.
That is really interesting, sadly I don't have quite as much gear as you, I only have
a basic logic analyser, but I am not currently trying to fix a MS650 memory board. You
mentioned a KA650 architecture manual and you had a PDF of it in the video. I couldn't
find it on Manx? Where can I find it?
Thanks
Rob
-----Original Message-----
From: cctech <cctech-bounces at classiccmp.org> On Behalf Of Joe Zatarski via
cctech
Sent: 16 June 2019 02:33
To: cctech at classiccmp.org
Subject: DEC KA650 VAX memory troubleshooting (video)
Hey Everyone,
I just thought I'd share a video of how I'm going about troubleshooting the
bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to do a lot
of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write them
up properly as well. I wasn't able to find a printset for the RAM card itself, so I
assume one doesn't exist in digital form yet. I have documented what bit and
memory range each DRAM on the card corresponds to, which may help
someone troubleshooting in the future
Regards,
Joe Zatarski
7:38 a.m.
sorry, the technical manual actually, which has an architecture *chapter*
http://www.bitsavers.org/pdf/dec/vax/650/
The idea, eventually, is that I will publish my notes so that you wouldn't
need the logic analyzer, at least for the 8MB board. I just had it hooked
up, so I demoed it. The notes will include a mapping of bits and adresses
to ICs so that you can narrow down which chip from just the ROM monitor. I
don't have a 16MB board, but somebody could honestly probably figure out
the mapping with a logic probe if they had to, just probe /cas while
writing various test addresses, then check the data line while writing
various test patterns. I also came up with some data that produces useful
ECC bits, like all 1s, all 0s, one bit set only, and one bit clear only.
That will also be in the notes when I write it up.
On Sun, Jun 16, 2019, 3:25 AM Rob Jarratt <robert.jarratt at ntlworld.com>
wrote:
That is really interesting, sadly I don't have
quite as much gear as you,
I only have a basic logic analyser, but I am not currently trying to fix a
MS650 memory board. You mentioned a KA650 architecture manual and you had a
PDF of it in the video. I couldn't find it on Manx? Where can I find it?
Thanks
Rob
-----Original Message-----
From: cctech <cctech-bounces at classiccmp.org> On Behalf Of Joe Zatarski
via
cctech
Sent: 16 June 2019 02:33
To: cctech at classiccmp.org
Subject: DEC KA650 VAX memory troubleshooting (video)
Hey Everyone,
I just thought I'd share a video of how I'm going about troubleshooting
the
bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to do
a
lot
of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write
them
up properly as well. I wasn't able to find a
printset for the RAM card
itself, so I
assume one doesn't exist in digital form yet.
I have documented what bit
and
memory range each DRAM on the card corresponds
to, which may help
someone troubleshooting in the future
Regards,
Joe Zatarski
9:38 a.m.
Thanks, I am aware of BitSavers of course, so I am not sure why I didn?t think to look
there!
Regards
Rob
From: Joe Zatarski <joezatarski at gmail.com>
Sent: 16 June 2019 15:39
To: rob at jarratt.me.uk
Cc: General Discussion: On-Topic Posts <cctech at classiccmp.org>
Subject: Re: DEC KA650 VAX memory troubleshooting (video)
sorry, the technical manual actually, which has an architecture *chapter*
http://www.bitsavers.org/pdf/dec/vax/650/
The idea, eventually, is that I will publish my notes so that you wouldn't need the
logic analyzer, at least for the 8MB board. I just had it hooked up, so I demoed it. The
notes will include a mapping of bits and adresses to ICs so that you can narrow down which
chip from just the ROM monitor. I don't have a 16MB board, but somebody could honestly
probably figure out the mapping with a logic probe if they had to, just probe /cas while
writing various test addresses, then check the data line while writing various test
patterns. I also came up with some data that produces useful ECC bits, like all 1s, all
0s, one bit set only, and one bit clear only. That will also be in the notes when I write
it up.
On Sun, Jun 16, 2019, 3:25 AM Rob Jarratt <robert.jarratt at ntlworld.com
<mailto:robert.jarratt at ntlworld.com> > wrote:
That is really interesting, sadly I don't have quite as much gear as you, I only have
a basic logic analyser, but I am not currently trying to fix a MS650 memory board. You
mentioned a KA650 architecture manual and you had a PDF of it in the video. I couldn't
find it on Manx? Where can I find it?
Thanks
Rob
-----Original Message-----
From: cctech <cctech-bounces at classiccmp.org <mailto:cctech-bounces at
classiccmp.org> > On Behalf Of Joe Zatarski via
cctech
Sent: 16 June 2019 02:33
To: cctech at classiccmp.org <mailto:cctech at classiccmp.org>
Subject: DEC KA650 VAX memory troubleshooting (video)
Hey Everyone,
I just thought I'd share a video of how I'm going about troubleshooting the
bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to do a lot
of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write them
up properly as well. I wasn't able to find a printset for the RAM card itself, so I
assume one doesn't exist in digital form yet. I have documented what bit and
memory range each DRAM on the card corresponds to, which may help
someone troubleshooting in the future
Regards,
Joe Zatarski
17 Jun
17 Jun
5:56 p.m.
OK, so where should a thing like this go: https://pastebin.com/taQwaTV6
Anybody got a decent place to upload that? it's my notes on the MS650-AA,
and more generally the KA650 CMCTL memory subsystem.
Includes my theory of operation of the CMCTL, the organization of memory,
the ECC equations (kinda, the info is there to derive them), explanations
of the signals on the memory bus, and most importantly, a list of which
bits and RAM regions correspond to the 312 DRAMs on the board.
On Sat, Jun 15, 2019 at 8:33 PM Joe Zatarski <joezatarski at gmail.com> wrote:
Hey Everyone,
I just thought I'd share a video of how I'm going about troubleshooting
the
bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to do
a lot
of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write
them up
properly as well. I wasn't able to find a printset for the RAM card
itself, so I assume one doesn't exist in digital form yet. I have
documented what bit and memory range each DRAM on the card corresponds to,
which may help someone troubleshooting in the future
Regards,
Joe Zatarski
18 Jun
18 Jun
3:22 a.m.
On 18/06/2019 01:56, Joe Zatarski via cctech wrote:
OK, so where should a thing like this go:
https://pastebin.com/taQwaTV6
Anybody got a decent place to upload that? it's my notes on the MS650-AA,
and more generally the KA650 CMCTL memory subsystem.
Includes my theory of operation of the CMCTL, the organization of memory,
the ECC equations (kinda, the info is there to derive them), explanations
of the signals on the memory bus, and most importantly, a list of which
bits and RAM regions correspond to the 312 DRAMs on the board.
Sounds ideal for the Computer History Wiki:
http://gunkies.org/wiki/Main_Page.
Antonio
--
Antonio Carlini
antonio at acarlini.com
23 Nov
23 Nov
10:28 p.m.
New subject: DEC KA650 VAX memory troubleshooting
Well, I finally got around to posting this on the CHWiki, in case
anybody was curious about this.
https://gunkies.org/wiki/DEC_KA650_Memory_Subsystem
On 6/17/19 7:56 PM, Joe Zatarski wrote:
OK, so where should a thing like this go:
https://pastebin.com/taQwaTV6
Anybody got a decent place to upload that? it's my notes on the
MS650-AA, and more generally the KA650 CMCTL memory subsystem.
Includes my theory of operation of the CMCTL, the organization of
memory, the ECC equations (kinda, the info is there to derive them),
explanations of the signals on the memory bus, and most importantly, a
list of which bits and RAM regions correspond to the 312 DRAMs on the board.
On Sat, Jun 15, 2019 at 8:33 PM Joe Zatarski <joezatarski at gmail.com
<mailto:joezatarski at gmail.com>> wrote:
Hey Everyone,
I just thought I'd share a video of how I'm going about
troubleshooting
the bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to
do a
lot of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write
them up
properly as well. I wasn't able to find a printset for the RAM
card itself, so I assume one doesn't exist in digital form yet. I have
documented what bit and memory range each DRAM on the card corresponds
to, which may help someone troubleshooting in the future
>
> Regards,
> Joe Zatarski 
24 Nov
24 Nov
6:27 a.m.
New subject: DEC KA650 VAX memory troubleshooting
Wow. Very nicely done! Which logic analyzer did you use to capture those displays?
73 Eugene W2HX
________________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Joseph Zatarski via
cctalk <cctalk at classiccmp.org>
Sent: Sunday, November 24, 2019 1:28 AM
To: General Discussion: On-Topic Posts
Subject: Re: DEC KA650 VAX memory troubleshooting
Well, I finally got around to posting this on the CHWiki, in case
anybody was curious about this.
https://gunkies.org/wiki/DEC_KA650_Memory_Subsystem
On 6/17/19 7:56 PM, Joe Zatarski wrote:
OK, so where should a thing like this go:
https://pastebin.com/taQwaTV6
Anybody got a decent place to upload that? it's my notes on the
MS650-AA, and more generally the KA650 CMCTL memory subsystem.
Includes my theory of operation of the CMCTL, the organization of
memory, the ECC equations (kinda, the info is there to derive them),
explanations of the signals on the memory bus, and most importantly, a
list of which bits and RAM regions correspond to the 312 DRAMs on the board.
On Sat, Jun 15, 2019 at 8:33 PM Joe Zatarski <joezatarski at gmail.com
<mailto:joezatarski at gmail.com>> wrote:
Hey Everyone,
I just thought I'd share a video of how I'm going about
troubleshooting
the bad DRAMs on my MS650 memory board.
https://youtu.be/eDMhdAEFEgc
I apologize for the shaky-cam, I don't have a tripod, and I needed to
do a lot
of panning anyway.
I will be sharing my notes on the MS650 once I have a chance to write
them up
properly as well. I wasn't able to find a printset for the RAM
card itself, so I assume one doesn't exist in digital form yet. I have
documented what bit and memory range each DRAM on the card corresponds
to, which may help someone troubleshooting in the future
>
> Regards,
> Joe Zatarski
7:35 a.m.
New subject: DEC KA650 VAX memory troubleshooting
I used an HP 16700A, which you can see in the video I linked some time back:
https://youtu.be/eDMhdAEFEgc
On 11/24/19 8:27 AM, W2HX wrote:
Wow. Very nicely done! Which logic analyzer did you
use to capture those displays?
73 Eugene W2HX
________________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Joseph Zatarski via
cctalk <cctalk at classiccmp.org>
Sent: Sunday, November 24, 2019 1:28 AM
To: General Discussion: On-Topic Posts
Subject: Re: DEC KA650 VAX memory troubleshooting
Well, I finally got around to posting this on the CHWiki, in case
anybody was curious about this.
https://gunkies.org/wiki/DEC_KA650_Memory_Subsystem
On 6/17/19 7:56 PM, Joe Zatarski wrote:
> OK, so where should a thing like this go: https://pastebin.com/taQwaTV6
>
> Anybody got a decent place to upload that? it's my notes on the
> MS650-AA, and more generally the KA650 CMCTL memory subsystem.
>
> Includes my theory of operation of the CMCTL, the organization of
> memory, the ECC equations (kinda, the info is there to derive them),
> explanations of the signals on the memory bus, and most importantly, a
> list of which bits and RAM regions correspond to the 312 DRAMs on the board.
>
> On Sat, Jun 15, 2019 at 8:33 PM Joe Zatarski <joezatarski at gmail.com
> <mailto:joezatarski at gmail.com>> wrote:
> >
> > Hey Everyone,
> >
> > I just thought I'd share a video of how I'm going about
> troubleshooting the bad DRAMs on my MS650 memory board.
> >
> > https://youtu.be/eDMhdAEFEgc
> >
> > I apologize for the shaky-cam, I don't have a tripod, and I needed to
> do a lot of panning anyway.
> >
> > I will be sharing my notes on the MS650 once I have a chance to write
> them up properly as well. I wasn't able to find a printset for the RAM
> card itself, so I assume one doesn't exist in digital form yet. I have
> documented what bit and memory range each DRAM on the card corresponds
> to, which may help someone troubleshooting in the future
> >
> > Regards,
> > Joe Zatarski
8:13 a.m.
New subject: DEC KA650 VAX memory troubleshooting
Those waveform window displays are from an HP / Agilent 16700 series logic
analyzer. Easy to recognize the HP-UX U/I if you have used one.
On Sun, Nov 24, 2019, 6:46 AM W2HX via cctalk <cctalk at classiccmp.org> wrote:
Wow. Very nicely done! Which logic analyzer did you
use to capture those
displays?
73 Eugene W2HX
________________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Joseph Zatarski
via cctalk <cctalk at classiccmp.org>
Sent: Sunday, November 24, 2019 1:28 AM
To: General Discussion: On-Topic Posts
Subject: Re: DEC KA650 VAX memory troubleshooting
Well, I finally got around to posting this on the CHWiki, in case
anybody was curious about this.
https://gunkies.org/wiki/DEC_KA650_Memory_Subsystem
1614
days inactive
1775
days old
9 comments
5 participants
participants (5)
-
a.carlini＠ntlworld.com -
glen.slick＠gmail.com -
joezatarski＠gmail.com -
robert.jarratt＠ntlworld.com -
w2hx＠w2hx.com