Is there anything I need to look out for when purchasing an EPROM
eraser? As part of my current project I'm looking to purchase one.
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/ |
>
>Subject: RE: Kaypro movcpm.com
> From: "Chuck Guzis" <cclist at sydex.com>
> Date: Sat, 15 Sep 2007 09:50:08 -0700
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 15 Sep 2007 at 6:49, dwight elvey wrote:
>
>> My understanding of movcpm.com is that it needs to be the
>> exact one that comes with that version. I beleive it has
>> tables of addresses to replace.
>
>Just so. Since MOVCPM contains a copy of CP/M itself, said copy also
>contains a serial number, which must match the one of the system
>you're executing MOVCPM on. If you've got a debugger, the point
>where the check is made is easy to find and disable, however.
I don't know about a copy of CP/M but it does ahve a table of all
the addresses inside CP/M (CCP, BDOS and BIOS)that get relocated.
If the system and MOVCPM are from differnt systems (say kayII and
a 4/84) it's very likely the BIOS varies enough that the BIOS
will get mashed. The serial numbmer (besides copyright) was to keep
the two matched or prevent a mess.
>Part of DRI's OEM agreement was that each copy of CP/M had to be
>serialized.
There is that but it's a seperate issue.
Allison
>Cheers,
>Chuck
>
>Subject: Re: 8-bitters and multi-whatever
> From: "Chuck Guzis" <cclist at sydex.com>
> Date: Thu, 13 Sep 2007 15:59:59 -0700
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 13 Sep 2007 at 17:36, Roy J. Tellason wrote:
>
>> > And I'd also disqualify device-sharing, such as a MAC (multiple
>> > access controller) between an I/O device and two computers. Those go
>> > WAY back...
>>
>> I'm not familiar with such stuff.
>
>Ah, showing my age. "Back in the day" you might have two otherwise
>independent mainframes and, say, two printers. To have a system do
>nothing but wait for a print job to finish while only one of the
>printers was busy is a huge waste of resources. A card punch might
>be an infrequenly used piece of equipment, so why have two? Or a
>printer could be offline for maintenance, but why take the machine it
>was attached to down also? Or, instead of having two banks of 8 tape
>drives for two machines, why not whittle that down to, say 12, and
>allow the drives to be shared? IIRC, most vendors offered some sort
>of a MAC facility, even if it was a QSE. CDC certainly did.
Most MAC setups again were master/slave. An example was BOCES/LYRICs
PDP-10/TOPS-10 timeshare system that had a PDP-8I as the comms frontend
(switch). The PDP-8 served as an intelligent peripheral but it's
dectapes were not available to the 10.
>Of course, direct coupling of computers was also done, either via a
>special I/O device or even shared bulk core. But we never called
>that "networking".
Mostly because it was a clear master slave lashup. Generally/loosely
networking implied more than two machines and a more general ability
to transfer/communicate as needed be it files, shared devices or some
combination of both with any machine being able to initiate and
communicate as a peer to others that could do same or similar.
Allison
Hi
Lots of systems got packaged in those corporate cabs. You imply that
its just one Cab. Is that so?
The only real way to tell is to get the model numbers off of the back's
of the units inside. Where is this system located?
A crane sounds bit much. You might want to check under the cabinet for
wheels. Has it really been there since 1977? If so there are a lot
things that degrade with time. Do not under any circumstances turn it
on.
All of the power supplies will need overhauling and the capacitors
replaced / reformed.
If you have looked inside the cab what did you see? If it dates to 1977
then it is in the time frame when I worked at DEC. A bit more detail may
ring a (very old) bell with me.
Rod Smallwood
The DecCollector
-----Original Message-----
From: cctech-bounces at classiccmp.org
[mailto:cctech-bounces at classiccmp.org] On Behalf Of Tobias Russell
Sent: 15 September 2007 21:01
To: cctalk at classiccmp.org
Subject: Help identifying a PDP-11
Hi,
Can anyone help me identify my latest PDP-11 rescue. Not been able to
get a good look at it yet as it is in a room packed (and I mean packed)
with junk. Machine consists of a DEC Datasystems cab (about 35-40U with
a blue bottom panel, pretty similar to light blue cabs here:
http://www.computermuseum.li/Liste/Digital/PDP11.70.4.html)
I'm not familiar with the DEC Datasystems versions of PDP-11s. Does
anyone have any background information on them?
Also, I'm pretty sure I've not lucked out and found an 11/70 as no
toggle switch console, any ideas on what other models were fitted to
these cabs. I'm guessing 11/34.
Machines is fantastic condition having been stored for last 30 years.
Comes with 2 x RK07s (in floor standing cabs) and a tape drive.
Only downside is I'm having to hire a crane to remove the machine (as
its on 1st floor).
Any advice on moving RK07 drives? Do I need to lock heads?
Many thanks,
Toby
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> From: mcguire at neurotica.com> > This is very true. EPROMs store their bits in "floating gates", > which are conductive areas which are totally surrounded by an > insulating material. Exposure to UV light causes that insulating > material to become partially conductive, allowing the charge to drain > from the floating gate...and that charge has to GO somewhere.
Hi
The charge is really small. Once it is connected to the rest
of the chip, it is discharged enough. You don't need to pass
the charge to the outside. I have small eraser that doesn't
even have uniform contact and it erases just fine. In any case, the gate is like a capacitor. You put a charge
on one side and an equal but opposite charge will exist
on the other side. When the leads are connected together,
there is rarely any static charge left. This is because the ability
to hold charge is related to the capacitance. The capacitance
of an object to the rest of the world is small but across
the plates it is orders of magnitude larger. The same is true
for the floating gate.
The problem is that you are thinking of the charge on the gate
as though it were completely isolated from the rest of the
world. This isn't true or it would be useless to control current
in the transistor. It has to have a relatively large capacitance
to transistor.
Dwight
_________________________________________________________________
Capture your memories in an online journal!
http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us
>
>Subject: Next EPROM Question - Sizes
> From: "Zane H. Healy" <healyzh at aracnet.com>
> Date: Sun, 16 Sep 2007 19:34:43 -0700
> To: classiccmp at classiccmp.org
>
>I was happy to find earlier today that while I gave away most of my
>tubes of chips and other parts about 3 years ago as I wasn't doing
>anything with chips, I still have a 4 partial tubes of 27256's and
>27C256's. IIRC, thankfully I'd thought they might be useful to hang
>onto.
>
>So the question of the minute is this, is it possible to substitute a
>27C256 for a smaller 27C128?
Yes, with the exception that it's larger and has one more address pin.
Allison
>
>Subject: Re: Help identifying a keyboard?
> From: woodelf <bfranchuk at jetnet.ab.ca>
> Date: Sun, 16 Sep 2007 17:48:36 -0600
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Seth Morabito wrote:
>> Hi folks,
>>
>> Can anyone help identify the keyboard in these photos? (apart from the
>> obvious, that it's made by Stackpole and has a part number of 86-90-0048 ;)
>>
>> http://www.loomcom.com/junk/stackpole1.jpg
>> http://www.loomcom.com/junk/stackpole2.jpg
>>
>> I picked it up for fifty cents at a swap meet in the hopes that it might
>> be an ASCII keyboard that I could use in an Apple I replica, but given
>> that it has a 40-pin DIP socket, it's clearly not (it was very early in
>> the morning, what can I say). It has a five-pin power header on the top
>> left, two red LED indicators, the aforementioned 40-pin DIP socket, and
>> only one IC, an SN7414N, so it's obviously not doing much logic.
>Well it is a nice keyboard ... better built than todays 39 cent keyboards.
>You could be missing the keyboard encoder chip ( the 40 pin socket).
>But that still leaves where do you get output from.
>
>> -Seth
>>
Sounds like similar to a keyboard I have but the chip is an 8048 not a
keyboard encoder. The data was output on the 5pin connector in serial
format. The 8048 micro did the key scanning and serial IO.
Allison
----- Original Message -----
>From: <cctalk-request at classiccmp.org>
>To: <cctalk at classiccmp.org>
>Sent: Fri, 14 Sep 2007 20:22:26 -0400
>From: "Ralph E. Dodd" <redodd at comcast.net>
>Subject: Kaypro movcpm.com
>Hello Kaypro fans,
>I'd like to put a Kayplus83 rom into a Kaypro II so I can add double sided
>drives and have all the other nice stuff that the >rom provides. It's the
>early model with an 81-110B1 motherboard that needs the wiring for the
>floppy side 2 added. The >Advent Turborom manual has the wiring mods
>needed for side 2 access. The Kaypro II comes with a 2K eprom and the
> >Kayplus83 is an 8K. Again the Turborom manual tells how to access a 4K
>rom and adding access to the A12 line should >make the 8K rom work. I
>think that I've got that part all worked out. To make the Kayplus boot
>disk, you have to have a >system size of 62K or smaller. My Kaypro II disk
>has a 64K system. When I run movcpm.com to change the system >size, the
>program hangs. I also tried the version of movcpm that comes with the
>Kaypro 4 and that hangs also. So >question (1) is, has anyone gotten this
>program to work or is there another easy way to do this? There's a blurb
>on the net >about the Kaypro 1 movcpm not working !
>right but I didn't see anything about the Kaypro II version. Question (2)
is, should the movcpm program from another >Kaypro model work on a II or are
they all specific to 1 model. TIA.
>Ralph
I was using a boot disk made from a downloaded image. After a long search,
I found a copy of the original SBasic boot disk that I got when I bought the
Kaypro II. Movcpm worked properly and I was able to sysgen a 60K system so
the KayPlus configuration program worked. Thanks for all the help.
Ralph
