ard at p850ug1.demon.co.uk (Tony Duell) wrote:
> A bit later, but I have a set of 6 books entitled 'Modern Electrical
> Engineering' which I estimate date from between 1910 and 1920. These
> contain a description of the Baudot telegraph system with diagrams of the
> machinerey, circuits for the 'Quadruplex', etc. It appears to have been
> well in use by then.
>
> Said books also contain a description of a lovely electromechanical FIFO
> system used to store train descriptors on the London Underground (and its
> associated binary to 1-of-n decoder) ...
which I suppose are still in use in the New York subway :-)
**vp
>
>Subject: Re: MITS 8800B CPU Board
> From: "Randy McLaughlin" <cctech at randy482.com>
> Date: Wed, 15 Jun 2005 14:30:56 -0500
> To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
>
>From: "Tom Jennings" <tomj at wps.com>
>Sent: Wednesday, June 15, 2005 2:24 PM
>
>
>> On Tue, 14 Jun 2005, Allison wrote:
>>
>>>> di ; everyone shut up, please
>>>> lxi h, epromstartaddress ; EPROM address
>>>> lxi d, epromstartaddress ; likewise, I'm sure,
>>>> lxi b, 2048 ; BC=EPROM size
>>>> ldir ; whirl!
>>>> in 0 ; disables EPROM
>>>> ...
>>>>
>>>
>>> Only one detail... the proposed cpu was 8080 (MITS 8800B)!
>>
>>> Horrid as it's mixed 8080/z80 code.
>>
>>
>> Oh whatever -- it was an explanation, not a hex image for you to burn!
>
>There were plenty of Z80 assemblers that used Intel mnemonics with Z80
>extensions and the code is correct for them. The first great Z80 assembler,
>TDL is a good example.
I use a couple of them TDL included. I happen to like the intel flavor z80
opcodes.
Allison
If you're still actually somewhat interested in this,
I'd be more then happy to provide the neccisary development
skills :)
On 2/2/05 8:55 PM, "Michael Nadeau" <menadeau at comcast.net> wrote:
> The publisher limits the amount of material from the book I can post. The
> bigger problem for me is a lack of time and Web development skills.
>
>> "Computer Collector Newsletter" wrote:
>>
>>> Mike Nadeau: it's time for an updated edition to "Collectible
>>> Microcomputers"
>>
>> Actually, all he needs is a web site with the current prices. The
>> information and pictures in the book are never going to change.
>>
>> Paul Pennington
>> Augusta, Georgia
>>
>>
>
>
>
> Message: 35
> Date: Sun, 12 Jun 2005 20:50:59 -0700 (PDT)
> From: Chris M <chrism3667 at yahoo.com>
> Subject: how to image pre dos 2.0 disks (?)
> To: cctech at classiccmp.org
> Message-ID: <20050613035059.97966.qmail at web61016.mail.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> Winimage has beem doing a pretty good job until now,
> but it chokes on some really early stuff. It also
> doesnt like some diagnostic programs, that are not
> recognized as FAT. And you also cant, to my knowledge
> dump an image to a disk differing from the original.
> Any suggestions?
>
CP/M fans use a DOS program named 'Teledisk' to make floppy images,
maybe this works for you (I never used it).
If you have access to a *NIX-like OS (Linux, FreeBSD, NetBSD, ...) you
can try the 'dd' utility.
Hope this helps.
______________________________________________
Renovamos el Correo Yahoo!
Nuevos servicios, m?s seguridad
http://correo.yahoo.es
>
>Subject: Re: MITS 8800B CPU Board
> From: "Dwight K. Elvey" <dwight.elvey at amd.com>
> Date: Mon, 13 Jun 2005 17:12:04 -0700 (PDT)
> To: cctalk at classiccmp.org
>
>>From: "river" <river at zip.com.au>
>>
>>Hi,
>>
>>Thanks for your replies. I found the relevant information.
>>
>>I have an extensive inventory and can source the parts and get this poor,
>battered board back to its old self again. However, looking through the doco I
>noticed that the 8800B requires a display/control and interface boards. A
>question for those of you that own a MITS8800 - does it need those boards for a
>turnkey system? Can I plug the CPU board into the backplane and run it without
>the d/c and i/f cards, assuming I set up the ROM and RAM cards for the system?
>If not, (since I do not have the d/c and i/f cards) I'll have to try and build
>them from the cct diagrams I have obtained. This is do-able (but a lot of work)
>if I can get my hands on some blank S100 w/wrap boards, but I noticed there's a
>1702 EPROM chip and I'd need to get the memory map for this chip to burn my own.
>>
>>Failing that, and it's all too hard and bothersome for me, is there anyone that
>would need a repaired 8800 CPU card for trade or anything similar?
>>
>>rgds
>>river
>>
>
>Hi
> It should work on a turnkey. Almost everything goes
>through the S100 bus. Only the direct connect of the
>data bus goes directly between the panel and the CPU board.
>I don't think that is needed. You will have to have code
>residing at address 0000. This is not common. Most
>expected a working front panel that could load a boot
>address.
> Some ROM boards have a way to be at 0000 after reset
>and then switch to someplace else once things are booted.
> Don't give up on it. When there is a will, there will
>be a way.
>Dwight
Yes, you will have to have rom at 0000h though and Mwrite
was derived and delivered from the front pannel if memory
serves. So that means ram will have to be set up to not
require Mwrite. Either that or you will have to through
something small together to create Mwrite.
As to mapping rom out once operational, thats a later problem.
It's fairly easy to do.
Allison
>
>Subject: RE: PDP 11/23 PLUS system for sale
> From: Paul Koning <pkoning at equallogic.com>
> Date: Wed, 15 Jun 2005 14:28:02 -0400
> To: cctalk at classiccmp.org
>
>>>>>> "Allison" == Allison <ajp166 at bellatlantic.net> writes:
>
> Allison> Actually depending on OS and general usage the critical
> Allison> factor for the DEQNA was not rev but, is it functional at
> Allison> all? Most of the DEQNAs I've touched and used either worked
> Allison> or were dead, rev was a minor issue save for certain OS
> Allison> support issues. One of the REV issues was that the more
> Allison> reworked versions tended to have more failures (IE plain old
> Allison> dead) resulting from greater amounts of handeling and
> Allison> use/abuse. For Q-bus 11s the DEQNA was an acceptable
> Allison> device.
>
>>From what I remember (very blurry now) DEQNAs were known to corrupt
>data. That was very obvious on VAXclusters, which is why VMS
>eventually took them off the supported device list permanently. But
>it's an issue for any application (except, *maybe*, when running TCP
>since the TCP layer checksum may help -- or may not, it's not that
>strong...). That applies just as much for PDP11s.
>
> paul
No they _could_ corrupt data, not they did all the time. The differnce
was the error rate was not what DEC wanted for transactions. The VAX
people put pressure to not have to test the data as LAVCs (Local Area
VAX Clusters) were popular to a point and required a very high level
of data (code!) integrety. The frequency of the failure was related
to the traffic level on the local loop.
The second level of that was plain product improvement. The DEQNA
was a dense board with a low MTBF (errors excluded) and field support
and board costs were high. Replacement (supported [aka endorsed] by
the VAX folks) was a desireable thing if the new card was more robust
[higher MTBF and fewer "bugs"].
I was part of the uVAX side of things as the products I was involved with
(LPS40 and LPS20 network printers) used an embedded microVAX and the
LPS40 inparticular was a complete BA23 sans disks and netbooted from
host VAX. It was "interesting" string of events. Such was the fun
of being there.
Allison
Cleaning up here and just cames across this ; MicroVAX-II IAPX86 Assembler
and Utilities Package VMS backup format. P/N 483967-001 Version 4.3. By
Intel. Comes on CompacTape. Untested but looks unused.
Anybody interested ?
I also have :
VAX/VMS-MICROVMS V4 MUP TK50 (2x)
VAX/VMS V4.6 BIN TK50
VAX/VMS V4.6 BIN TK50 MANDATORY UPDATE
and
ME8002 VAX RDB/VMS MULTI V4.1 16MT9
ME8007 VAX RDB/VMS V4.1 STANDARD16MT
Stefan.
-------------------------------------------------------
http://www.oldcomputercollection.com
>
>Subject: RE: PDP 11/23 PLUS system for sale
> From: "Fred N. van Kempen" <waltje at pdp11.nl>
> Date: Wed, 15 Jun 2005 20:09:17 +0200 (MEST)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On Wed, 15 Jun 2005, Allison wrote:
>
>> Actually depending on OS and general usage the critical factor for
>> the DEQNA was not rev but, is it functional at all? Most of the
>> DEQNAs I've touched and used either worked or were dead, rev was a
>> minor issue save for certain OS support issues.
>I have about 20, and they're all OK. Screwy, but OK.
>
>> One of the REV
>> issues was that the more reworked versions tended to have more
>> failures (IE plain old dead) resulting from greater amounts of
>> handeling and use/abuse. For Q-bus 11s the DEQNA was an
>> acceptable device. DELQAs while nicer were scarcer.
>I don't think that *now*, DELQA's are scarcer. They may have
>been at the time, but not now.
Nope. DELQAs appeared as Qbus was becomming less common (AKA microVAXen)
and many of those when the DEQNA was retired it was because the uVAX
had been too. Qbus uVAXen were often replaced by 3100s and other non-Q
systems. Field circus was also slow to replace them with DELQAs
unless the DEQNA had failed or was at issue for OS or other misfunctions.
Bluntly FS was cheap and one of the last profit centers. By shear
force of numbers there were never as many DELQAs as DEQNAs manufactured.
Allison
>
>Subject: RE: PDP 11/23 PLUS system for sale
> From: Paul Koning <pkoning at equallogic.com>
> Date: Wed, 15 Jun 2005 12:40:19 -0400
> To: cctalk at classiccmp.org
>
>>>>>> "Julian" == Julian Wolfe <Wolfe> writes:
>
> Julian> I wasn't aware of this. Are you interested in the 11/23 box
> Julian> if they are a suitable revision?
>
>Sorry, I should have been clearer. No, I'm not -- my point was that
>when you're posting information about the hardware, DEQNA rev is a
>pretty significant piece of data. (That's usual, I think -- typically
>things weren't so badly broken earlier on, and it certainly was quite
>rare for there to be anywhere near that many revisions. But the DEQNA
>designer was an unusual character, to put it very politely.)
>
> paul
Actually depending on OS and general usage the critical factor for
the DEQNA was not rev but, is it functional at all? Most of the
DEQNAs I've touched and used either worked or were dead, rev was a
minor issue save for certain OS support issues. One of the REV
issues was that the more reworked versions tended to have more
failures (IE plain old dead) resulting from greater amounts of
handeling and use/abuse. For Q-bus 11s the DEQNA was an
acceptable device. DELQAs while nicer were scarcer.
Allison
Hi,
I am just getting a PDP11/23plus. The CPU is already at home and I have
powered the machine up. Makes noise, turns fans, etc. If I start the
machine (running indicator lit) it gives me a dollar sign ('$') prompt
which seems to accept two character until it starts a new line.
Here a few (perhaps totally stupid - but I've never used such a toy
before) questions:
What's that?
What can I do from there?
Is it normal?
My machine lacks harddisk and floppy (at the moment, they have not
arrived yet). The monitor program (@-Prompt) seems to work correctly.
Regards,
Philipp :-)
