> Date: Tue, 13 May 2008 16:46:21 -0700 (PDT)
> From: Chris M
> off the cuff, if you're looking for one so you can
> interface an 8" drive to a pc, you might want to look
> at Dave Dunfield's info (don't ask me the url, just
> google "Dave's old computers" and you'll find it
> lickety-split). Unlikely every 8" drive will work, but
> many will I presume.
The CC II is a different beast from the CC IV and the generic PC-AT
style controller, using a plain-Jane uPD 765A with a different
convention for switching densities. It's basically the CCI without
the external drive connector (same PCB, just no connector). 22DISK,
Anadisk etc. support this controller during configuration.
If the OP wants to contact me off-list, I think I may have a CCII
that I'm willing to part with.
Cheers,
Chuck
Address Contents
000 000 000 000 000 000 000 000
000 000 000 001 000 000 000 000
000 000 000 010 000 000 000 000
000 000 000 010 000 000 000 000
-----Original Message-----
From: cctech-bounces at classiccmp.org
[mailto:cctech-bounces at classiccmp.org] On Behalf Of Mike Hatch
Sent: 14 May 2008 09:28
To: General Discussion: On-Topic Posts Only
Subject: Re: [personal] RE: PDP-8E diagnostic help needed
0-24 thats 0-16 Dec.
Don't know the 8's but that would suggest to me that 4 bits (1 chips
worth) are stuck somewhere leading to some address decoding ?. Does it
repeat higher up the addresses ?.
Mike.
----- Original Message -----
From: "Rod Smallwood" <RodSmallwood at mail.ediconsulting.co.uk>
To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
Sent: Tuesday, May 13, 2008 8:44 AM
Subject: [personal] RE: PDP-8E diagnostic help needed
> Now that's interesting..
>
> I have a PDP-8/e as well. I can't store in locations 000 000 000 000
to
> 000 000 011 000 (0 - 24 Dec)
> Above is OK
>
>
> If somebody has an answer to your problem. They might know something
> about mune.
>
> Rod Smallwood
>
>
>
>
> -----Original Message-----
> From: cctech-bounces at classiccmp.org
> [mailto:cctech-bounces at classiccmp.org] On Behalf Of Mark G. Thomas
> Sent: 09 May 2008 16:36
> To: cctech at classiccmp.org
> Subject: PDP-8E diagnostic help needed
>
> Hi,
>
> I've got a PDP-8E which I've almost got working.
>
> Can anyone here help me figure out this remaining problem?
>
> As I examine memory, the address lights count up to 01111, then go
back
> to 00000, instead of 10000. I can manually enter an address higher
than
> 1111, but the 10000 and 100000 bits don't stick -- they go low, as
soon
> as I hit the examine switch to step to the next memory location.
>
> I can manually load an address 1000000 or 10000000, and hit examine to
> see 1000001, 1000010, 1000011, etc..., but once I reach 1001111, it's
> back to 1000000.
>
> It was recommended to me that it might be the carry between E52 and
E37,
> or the E38 input multiplexer for bit 7 (on M8300), so last night I
> socketed and replaced all three of those ICs, but I still see the same
> symptoms.
>
> I have extender boards, so can access M8300 during operation. I
measured
> the carry line between E52 and E37 go low when I reach 1111, but the
> light for line 10000 doesn't light on the front panel on the next
> address, and I see the data from memory location 0000, 0001, etc.
> repeated, displayed as I continue to step through memory locations, as
> described above.
>
> Of course, if someone has a spare M8300 they would be willing to sell
> me, that's another option.
>
> Mark
>
>
> --
> Mark G. Thomas (Mark at Misty.com)
> voice: 215-591-3695
> http://mail-cleaner.com/
>
>
>
>
>
Hi Chris,
I've just found your posts about the CPT 9000 computer/word processor you have. I worked for CPT Corp. from 1978 thru 1989 and was one of the principle software developers for the CPT 9000. It was CPT's last effort to combine their dedicated word processing software with the, at the time, new PC-AT 286 computers coming into the market. I have lots of the original software for the 9000, much of it I wrote.
Personally, I would be very interested in purchasing this CPT 9000 system. I have been searching for one for a long time. If this e-mail somehow finds you, please reply. I would be a very $$$ serious buyer.
Thanks,
Rich Jones
Metasoft, Inc.
Tried to power up a Sun 3/80 mainboard...
Inductor L0500 (right near the power input) (I assume this is an
inductor by the L0500
marking on the PCB) smoked.... (pink smoke no less)
Anyone familiar with the 3/80 to give an idea of why this might have smoked.
Board appears in excellent condition, no foreign objects on the board,
no sign of any
shorts that I can see.
Would like to rescue this board. If it was a PC I'd look for bulging
electrolytics...
Anyone got a schematic for the 3/80 ? (I've never seen any Sun schematics).
-- Curt
Eric wrote:
>The G888 sense amps are designed to oscillate when no input is present.
Thanks, Eric - I'm glad I asked. I wrote a little program to read the
tapes (only about three lines of code - all it has to do is set the "GO" bit
in the TD8E command register) and I find that one of the units does indeed
give a nice 30kHz square wave on the timing track while the tape is moving.
The other unit unfortunately still gives the bogus 400kHz oscillations no
matter what.
I'm guessing that must mean that either the R/W head or the relay card is
bad. I can test the relay card by swapping it with the other unit, but luck
being what it is it's probably the head.
Darn - I assume TU56 heads are unobtainable these days.
Thanks again,
Bob
Now that my TD8E is fixed (maybe - I'm keeping my fingers crossed here)
I'm having problems with the TU56 drive electronics. Nothing works, neither
the diagnostic (DHTDAB) nor the OS/8 drivers.
Poking around, I've discovered that the RTT ("Read Timing Track") output
>from the drive has a constant square wave of about 400kHz (2.5us period),
regardless of what the drive is doing. It's there whether no matter which
unit is selected, no matter whether any unit is selected, no matter whether
the tape is moving or stopped, and even if there's no tape on the drive at
all. This is from checking the RTT output from the drive right at the cable
connector on the TD8E with a scope.
If I understand the way the TU56 works, then this a) about 15x the
frequency I'd expect to see on the timing track and b) I wouldn't expect
there to be an output from the TT when the tape isn't moving. Am I right
that this is really screwed up, or do I just not understand how it works?
Thanks,
Bob
> Poking around, I've discovered that the RTT ("Read Timing Track") output
> from the drive has a constant square wave of about 400kHz
> Am I right
> that this is really screwed up, or do I just not understand how it works?
--
That's the way it works. It drops to the correct frequency when the tape
is moving.
TC-11's and 08's depend on this in the 'up to speed' circuit.
Now that's interesting..
I have a PDP-8/e as well. I can't store in locations 000 000 000 000 to
000 000 011 000 (0 - 24 Dec)
Above is OK
If somebody has an answer to your problem. They might know something
about mune.
Rod Smallwood
-----Original Message-----
From: cctech-bounces at classiccmp.org
[mailto:cctech-bounces at classiccmp.org] On Behalf Of Mark G. Thomas
Sent: 09 May 2008 16:36
To: cctech at classiccmp.org
Subject: PDP-8E diagnostic help needed
Hi,
I've got a PDP-8E which I've almost got working.
Can anyone here help me figure out this remaining problem?
As I examine memory, the address lights count up to 01111, then go back
to 00000, instead of 10000. I can manually enter an address higher than
1111, but the 10000 and 100000 bits don't stick -- they go low, as soon
as I hit the examine switch to step to the next memory location.
I can manually load an address 1000000 or 10000000, and hit examine to
see 1000001, 1000010, 1000011, etc..., but once I reach 1001111, it's
back to 1000000.
It was recommended to me that it might be the carry between E52 and E37,
or the E38 input multiplexer for bit 7 (on M8300), so last night I
socketed and replaced all three of those ICs, but I still see the same
symptoms.
I have extender boards, so can access M8300 during operation. I measured
the carry line between E52 and E37 go low when I reach 1111, but the
light for line 10000 doesn't light on the front panel on the next
address, and I see the data from memory location 0000, 0001, etc.
repeated, displayed as I continue to step through memory locations, as
described above.
Of course, if someone has a spare M8300 they would be willing to sell
me, that's another option.
Mark
--
Mark G. Thomas (Mark at Misty.com)
voice: 215-591-3695
http://mail-cleaner.com/
I'm inquiring to see if anyone has a spare 10/100 card for the Apple Network
Server line. This is different than the usual Power Macintosh 10/100 FAST
Ethernet card -- it resembles that card, but has two LEDs (IIRC) instead of
four. If you have one that you are willing to part with or deal over, please
contact me off list. It would go to a good home, namely my 500 and 700 systems
(the 500 is sending you this message, in fact, and has been my primary
production server since 1998).
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com
-- All the sensitive [men] get eaten. -- "Ice Age" ----------------------------
The library is looking at a large collection of books, only one
slight problem, the seller won't back and ship. Local pickup isn't
really an option for us, as it's on the East Coast. Does anyone know
of any legit outfits that will show up at a storage unit, pack and
ship stuff?
I figure even though these aren't computer books (in this case) this
is close enough to on topic since there are those of us that have
problems like this with computer stuff.
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
