20 Jun
2005
20 Jun
'05
6:19 p.m.
Subject: Re: DEC M8350 - KA8E posibus interface
From: "vrs" <vrs at msn.com>
Date: Mon, 20 Jun 2005 16:46:49 -0700
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
> Forgot to answer this - MSC-8 hex MOS memory cards are handy - if they
> are 1/2 populated with 4Kbit chips, they are 16KW, fully populated
> with 4Kbit chips they are 32KW. If you happen to find the same card
> with 16Kbit (4116) chips, that's a whopping 128KW. You'll need a KT8A
> to address it, another late model card of limited use - RTS/8 used it,
> and I am pretty sure there was a RAM disk driver for OS/8 to use the
> upper 96KW as storage.
Is there a schematic {printset} around for MSC-8?
As to boards other than memory and CPU a front pannel board either
the 8E style or 8A is very handy too. Then serial IO cards are useful.
I use my 8f with two serial cards, one for console and one to simulate
a high speed PTR/PTP.
Allison
20 Jun
20 Jun
8:29 p.m.
On 6/20/05, Allison <ajp166 at bellatlantic.net> wrote:
Is there a schematic {printset} around for MSC-8?
I have never seen one (and I have plenty of printsets from back in the day).
I'd love to see one to verify differences between the 4Kbit and
16Kbit-stuffed boards. I'd consider taking one of my 16K boards and
turning it into 128K (easier desoldering than by unpopulating a 32K
board)
As to boards other than memory and CPU a front pannel
board either
the 8E style or 8A is very handy too.
The frontpanels for PDP-8/e/f/m are pretty obvious when seen on a pile
(and aren't seen on piles that often), but I agree that the
programmer's panel for the -8/a is something to look out for - I have
one ($50 a couple of years back), and would recommend them for anyone
who wants to do more than just hit a boot switch and fire up OS/8.
For the uninitiated, it plugs into the "standard" I/O board, the
DKC8AA, via two 40-pin cables. Pretty much any OS/8-running or
WPS-running -8/a I've ever seen, has a DKC8AA. It wasn't _required_,
but it was ordinary.
9:40 p.m.
From: "Ethan Dicks" <ethan.dicks at gmail.com>
On 6/20/05, Allison <ajp166 at bellatlantic.net>
wrote:
day).
I have one :-). About 20 11"x16.5" sheets.
Is there a schematic {printset} around for MSC-8?
I have never seen one (and I have plenty of printsets from back in the I'd love to see one to verify differences between
the 4Kbit and
16Kbit-stuffed boards. I'd consider taking one of my 16K boards and
turning it into 128K (easier desoldering than by unpopulating a 32K
board)
Mine describes a 16Kw board (half stuffed) and a 32Kw board.
Vince
9:55 p.m.
On 6/20/05, vrs <vrs at msn.com> wrote:
Visually, I've compared my 16K and 32K boards, and my 128K boards, and
the only difference can spot is type and quantity of DRAM. I'd like
to know for sure.
Also... does anyone know about the differences between 4116 and 4164
chips enough to answer the question if one could use 4164s as long as
one a) prevents the non-TTL supplies from reaching the chips (modify
board, modify sockets, modify pins...) and b) possibly tie up or tie
down the extra multiplexed address input. Can you refresh 1/4 of a
4164 and have just that part stay refreshed? I ask because I have a
serious wad of new 4164s from COMBOARD stock, but 128Kw of 4116s (8 x
12) is more than I have lying around.
-ethan
I have one :-). About 20 11"x16.5" sheets.
Handy.
I'd love
to see one to verify differences between the 4Kbit and
16Kbit-stuffed boards. I'd consider taking one of my 16K boards and
turning it into 128K (easier desoldering than by unpopulating a 32K
board)
Mine describes a 16Kw board (half stuffed) and a 32Kw board. 
21 Jun
21 Jun
3:58 p.m.
Also... does anyone know about the differences between
4116 and 4164
chips enough to answer the question if one could use 4164s as long as
one a) prevents the non-TTL supplies from reaching the chips (modify
What you need to do is isolate pins 1 and 8 from the board and reconnect
pin 8 to +5V IIRC
4116 4164
1 -5V N/C
8 +12V +5V
9 +5V A7
That leaves the extra address line tied high, so you only use 1/4 of the chip
board, modify sockets, modify pins...) and b) possibly
tie up or tie
down the extra multiplexed address input. Can you refresh 1/4 of a
4164 and have just that part stay refreshed? I ask because I have a
There were 2 types of 64K DRAM. One of them used 7 bit refresh (same as
the 4116, on the same pins), the other, older/rarer one need all 8
address lines to be used for the refresh (this was a royal pain on
Z80-based machines, where the CPU provides a 7 bit refresh only).
I have personally replaced the odd 4116 with a 4164 as I've just
described and had no problems. Maybe I've been lucky in finding 7-bit
refresh chips (which are the more common type), maybe it works anyway.
serious wad of new 4164s from COMBOARD stock, but
128Kw of 4116s (8 x
12) is more than I have lying around.
-tony
22 Jun
22 Jun
5:50 a.m.
At 11:58 PM 6/21/05 +0100, you wrote:
Tony,
This is good info. Someone should post it as a mini-FAQ.
Do you have any info on which ones used 7 bit refresh and which ones used
8 bit refresh?
Joe
Also... does
anyone know about the differences between 4116 and 4164
chips enough to answer the question if one could use 4164s as long as
one a) prevents the non-TTL supplies from reaching the chips (modify
What you need to do is isolate pins 1 and 8 from the board and reconnect
pin 8 to +5V IIRC
4116 4164
1 -5V N/C
8 +12V +5V
9 +5V A7
That leaves the extra address line tied high, so you only use 1/4 of the chip
board, modify sockets, modify pins...) and b)
possibly tie up or tie
down the extra multiplexed address input. Can you refresh 1/4 of a
4164 and have just that part stay refreshed? I ask because I have a
There were 2 types of 64K DRAM. One of them used 7 bit refresh (same as
the 4116, on the same pins), the other, older/rarer one need all 8
address lines to be used for the refresh (this was a royal pain on
Z80-based machines, where the CPU provides a 7 bit refresh only).
I have personally replaced the odd 4116 with a 4164 as I've just
described and had no problems. Maybe I've been lucky in finding 7-bit
refresh chips (which are the more common type), maybe it works anyway.
serious wad of new 4164s from COMBOARD stock, but
128Kw of 4116s (8 x
12) is more than I have lying around.
-tony
8:14 a.m.
On Wed, 22 Jun 2005, Joe R. wrote:
At 11:58 PM 6/21/05 +0100, you wrote:
Tony,
This is good info. Someone should post it as a mini-FAQ.
Do you have any info on which ones used 7 bit refresh and which ones used
8 bit refresh?
I've been taking useful messages and posting them to the FAQ myself,
attributing them to the original message author. I don't think Tony has
time to reply to messages and then go over to the KB to post them as well.
He has too much hacking to do.
So it's up to you to post them to the KB if you think they are worthwhile.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
Also...
does anyone know about the differences between 4116 and 4164
chips enough to answer the question if one could use 4164s as long as
one a) prevents the non-TTL supplies from reaching the chips (modify
What you need to do is isolate pins 1 and 8 from the board and reconnect
pin 8 to +5V IIRC
4116 4164
1 -5V N/C
8 +12V +5V
9 +5V A7
That leaves the extra address line tied high, so you only use 1/4 of the chip
board, modify sockets, modify pins...) and b)
possibly tie up or tie
down the extra multiplexed address input. Can you refresh 1/4 of a
4164 and have just that part stay refreshed? I ask because I have a
There were 2 types of 64K DRAM. One of them used 7 bit refresh (same as
the 4116, on the same pins), the other, older/rarer one need all 8
address lines to be used for the refresh (this was a royal pain on
Z80-based machines, where the CPU provides a 7 bit refresh only).
12:57 p.m.
I've been taking useful messages and posting them
to the FAQ myself,
Thank you.
attributing them to the original message author. I
don't think Tony has
time to reply to messages and then go over to the KB to post them as well.
He has too much hacking to do.
To be honest, yes I prefer hacking to writing FAQs, and I think I am
probably better and the former....
So it's up to you to post them to the KB if you think they are worthwhile.
For the record, if I've posted anything pnblically (including to this
list), then I have no objections to it being added to FAQs, the KB,
etc... I do ask that my name or e-mail address is somehow attached to it,
though, for obvious reasons.
-tony
6:06 p.m.
On Wed, 22 Jun 2005, Tony Duell wrote:
I've so far committed at least 5 of your messages to the KB, and put your
name to it. Basically, you ARE the KB at this point (not to minimize
anyone else's contributions of course).
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
So it's up
to you to post them to the KB if you think they are worthwhile.
For the record, if I've posted anything pnblically (including to this
list), then I have no objections to it being added to FAQs, the KB,
etc... I do ask that my name or e-mail address is somehow attached to it,
though, for obvious reasons. 
6:21 p.m.
Sellam wrote (re: Tony)
I've so far committed at least 5 of your messages
to the KB, and put your
name to it. Basically, you ARE the KB at this point (not to minimize
anyone else's contributions of course).
Hey, not to minimalize Tony's
contributions which are sincerely appreciated,
but there is a lot more than 5 entries in the KB.
Jay
6:38 p.m.
On Wed, 22 Jun 2005, Jay West wrote:
Sellam wrote (re: Tony)
Sure, sure. I didn't mean to imply that mine are the only ones. But
there are only 31 articles. That's pretty sad. There should be about 10
times that by now.
This is about the time that everyone should feel guilty and go over and
add something useful to the KB.
http://www.classiccmp.org/kb
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
I've so far committed at least 5 of your
messages to the KB, and put your
name to it. Basically, you ARE the KB at this point (not to minimize
anyone else's contributions of course).
Hey, not to minimalize Tony's
contributions which are sincerely appreciated,
but there is a lot more than 5 entries in the KB.
23 Jun
23 Jun
11:31 a.m.
Hey, not to minimalize Tony's contributions which
are sincerely appreciated,
but there is a lot more than 5 entries in the KB.
YEs, but to be fair, many of them came from the FAQ, and I am quite sure
some of my ideas ended up there ....
(Yes, this is a good thing. No I am not claiming to be the KB...)
-tony
22 Jun
22 Jun
12:53 p.m.
This is good info. Someone should post it as a
mini-FAQ.
Feel free...
Do you have any info on which ones used 7 bit refresh and which ones used
8 bit refresh?
I probably have the info somewhere, but I can't remember where (so I
might as well not have it!). All I can suggest is to try it. It won't do
any harm if you use the wrong sort of chip. If it works, then either it's
a 7 bit refresh type, or an 8 bit refresh one that still refreshes the
part you're using conrrectly.
-tony
7123
days inactive
7125
days old
12 comments
7 participants
participants (7)
-
ajp166＠bellatlantic.net -
ard＠p850ug1.demon.co.uk -
ethan.dicks＠gmail.com -
jwest＠classiccmp.org -
rigdonj＠cfl.rr.com -
vcf＠siconic.com -
vrs＠msn.com