Hi,
This a belated cross-post from Ottawa Freecycle.
I have a Tektronix 4107 colour graphics terminal, complete with manual
and keyboard. Free to good home, but you have to come and get it.
Jeff
>
>Subject: Re: Paper tape and 8th bit?
> From: woodelf <bfranchuk at jetnet.ab.ca>
> Date: Sat, 26 Aug 2006 16:48:38 -0600
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Chuck Guzis wrote:
>
>>
>> If you look at the preceding character, is there any correlation to the 8th
>> bit of the next one? The 8th bit just might be garbage left over and not
>> masked out.
>
>It could be binary.The driver is loaded in the top of memory, and
>seems to patch over a TTY driver. I don't have manual handy
>but it does have a bootstrap loader @ 80H I think, the first
>256 bytes to load in a hex loader.
PT and many of the 8080 micros didn't use the punch/reader (ASR33 usually)
in the same way as the PDP-8 and onter Minis. So conventions existed but
didn't always get applied the same.
It's not a bin tape, the manual has the source listing. Its a program "LIST"
of a PT 5k basic program that loads a long list of DATA nnn,nnn into memory
at an address and also pokes the output code of the program to point to VDM1
or Nominal IO depending of sense switch 8 (IN FF; ANI 80; JZ xxxx). Works on
IMSAI or Altair front pannal systems,useless for NS* (no sense sw at FFh).
I still have and use a VDM-1 in a Netronics Explorer 8085. I havent used PT
software since '76ish as I wrote a more compact minimal VT52 screen
emulation for it.
Allison
--- Jules Richardson <julesrichardsonuk at yahoo.co.uk
> wrote:
> aliensrcooluk at yahoo.co.uk wrote:
> > That means there are 5 different floppy disk
> > sizes that I now know of:
> >
> > 3"
> > 3.5"
> > 5"
> > 8"
>
> Add 2" to that - someone handed us a box of them t
he
> other week. I've got a
> feeling that 2.5" existed, too (and presumably by
5"
> you mean what's commonly
> called 5.25"?)
>
hmmm, now you have me slightly confused. After sendi
ng the message I did remember the 5.25" disks (as us
ed on BBC's etc.), but I assumed that 5" and 5.25" w
ere different sizes.
what's with 2" and 2.5", wouldn't they be too
fiddly and/or store too small amount of data
to make them worthwhile?
> > 12" (used on a special Sony Laservision machine)
>
> Hmm, Philips certainly had laservision players (go
t
> one here), but they're
> optical laserdisk players, not floppy (as in
> magnetic media) at all. I'd be
> surprised if a rival company could use the same na
me
> for a totally different
> technology! I've heard rumours of a 12" IBM format
> for one of their early
> mainframes, but I don't know if that's just urban
> legend or not.
>
No legend... give me a while and I'll find a link
to a pic of a 12" disk... Robert Bernardo
(Amiga enthusiast) has been pictured with one
at a retro event fairly recently.
> cheers
>
> Jules
>
>
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
>
>Subject: Re: Paper tape and 8th bit?
> From: ard at p850ug1.demon.co.uk (Tony Duell)
> Date: Sat, 26 Aug 2006 23:40:58 +0100 (BST)
> To: cctalk at classiccmp.org
>
>>
>> Hi Guys,
>>
>> I'm attempting to recover some software from paper-tape.
>>
>> Never actually had a PT reader in my "altair days", I fooled around
>> with magnetic tape systems (audio and 9-track), and later went to
>> the NorthStar disk system... Did a bit of paper-tape stuff with the
>> university systems, but I don't recall any real details.
>>
>> Anyway - I'm using an OP-80A which is a very simple manual feed
>> reader - you position a light over the unit and pull the tape through
>> wire guides over an optical sensor and it provides parallel data.
>>
>> This all appears to work OK.
>>
>> The tape I've been testing with is a Processor Technology "BASIC
>> VDM DRIVER" - it contains driver software for the PT VDM-1 video
>> board.
>>
>> My question - Does anyone know what they are using the 8th bit
>> for? - I get nicely readable ASCII BASIC source out of it, except
>
>Well, AFAIK few punches [1] or readers ever did anything with the 8th bit
>other than just transfer it to/from the system. So what it means depends
>on the device that punched that tape.
>
>[1] I say 'few', not none because the serial adapter board for the 4070
>can be set up to make this a locally-generated parity bit. In other words
>you can send it 7 bit characters (or 8 bit with the top bit ignored) and
>it will punch them with the 8th level an even parity bit. All
>link-selectable.
The punch and reader "dumb" devices though some did parity local that
was more exception than general practice.
>
>> that the 8th bit seems to be somewhat randomly set on certain
>> characters. If I strip the 8th bit I get what appears to be legit BASIC
>> code.
>>
>> I thought it might be parity, however this does not appear to be
In PT systems that may have been used as a "page" (VT or FF) marker.
I have the VDM-1 and the basic driver is ascii and the resulting program
load the binary driver.
>That would have been my first guess too. Normally even parity, since then
>totally blank and all holes are valid characters (the latter can be used
>to overpunch any other character, and was origianlly simply ignored by
>the system).
>
>Of course on a binary tape (true binary, not Intel-Hex or something),
>it's just anothe bit.
It's an Ascii punch of the PT basic "LIST: command. The 8th hole may
well be random trash or a particular character in memory that had the
high bit set.
>> the case - the codes 0A (00001010) and 0D (00001101) both
>> appear with the 8th bit clear - If the 8th bit were parity, one or
>> the other should have it set. Other characters always have it set,
>> for example 'T' (54) seems to always appears as (D4).
>
>Doe any character exist in both forms (with the top bit both clear and
>set)? If so, could it be something like a 'start of statement' marker or
>'start of keyword' or soemthing like that?
Easier, what is the punch pattern on the tape that corrosponds to the 8th
bit?
My tape is deeply burried since I stopped using back in '76. I know the
box it's in far enough down the stack to not warrent looking.
Allison
--- Jules Richardson <julesrichardsonuk at yahoo.co.uk
> wrote:
> aliensrcooluk at yahoo.co.uk wrote:
> > That means there are 5 different floppy disk
> > sizes that I now know of:
> >
> > 3"
> > 3.5"
> > 5"
> > 8"
>
> Add 2" to that - someone handed us a box of them t
he
> other week. I've got a
> feeling that 2.5" existed, too (and presumably by
5"
> you mean what's commonly
> called 5.25"?)
>
> > 12" (used on a special Sony Laservision machine)
>
> Hmm, Philips certainly had laservision players (go
t
> one here), but they're
> optical laserdisk players, not floppy (as in
> magnetic media) at all. I'd be
> surprised if a rival company could use the same na
me
> for a totally different
> technology! I've heard rumours of a 12" IBM format
> for one of their early
> mainframes, but I don't know if that's just urban
> legend or not.
>
> cheers
>
> Jules
>
Well here's the link to the pic:
http://www.dickestel.com/vintage2005.htm
It's picture 7, taken at the Vintage Computer Festiv
al 2005. I'm not entirely sure that is Robert holdin
g the disk, but he may have taken the picture instea
d?
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
Ray wrote:
> The Alpha chips were coded with EV - as in
>Electro Vlassic. :-)
That is one of those things, like VME, where the "real meaning" is
kept secret. There are several hypotheses, the other one that makes sense
is that it stands for Extended VAX (which, when you trace it out, means
Extended Virtual Address Extension [of the PDP-11], so there's still a little bit of PDP
in HP/DEC (until October...)
AXP however is known to mean nothing.
(could be a place shifting of something, e.g. VAX -> (v)AX[p]
> "I see where you're coming from - but I also know that writing a TIFF
> decoder is pretty straightforward; I wouldn't fancy doing the same
for > either JPEG or PDF (not sure about PNG, but I get the impression
that > it's pretty simple in nature)."
Noooooo!!!!!
Don't do it. The problem with writing your own decoder is that you may
not have your own set of reference images, so testing it would be
'interesting'. This is the major cause of security issues in software
at the moment. All it takes is one case where you mis-handle input, and
you have introduced a vulnerability into your application.
Unfortunately, you can't work on the basis that image data is not
hostile any more.
That's what application libraries are for. Yes, they are larger that
rolling your own, but they are also more robust.
> What I'm wondering is if one's feelings about "collectable" systems have
> more to do with the level of exposure to the internals of the hardware than
> with any intrinsic novelty of the hardware itself.
For me it really is more about the intellectual "value" in the design
than about any experiential component. To be honest, I don't particularly
like using computer to do things. I like making computers do things.
As a result, I don't run any commercial software and very little of the
other usual stuff most people run.
So what does make a machine interesting to me? There are the
architectures that I like, that make me feel an intellectual connection
to the creators. These are ones that are clean or elegant or orthogonal,
or whatever characteristic is particularly nice about it. These are
the machines like the various models of the PDP-11. On the other
hand there are those architectures that are far enough out of the
ordinary that they're interesting mostly in just how different they are.
The Intel 432 and the older AS/400s discussed recently fall into that
catagory. In some cases it's the details of the design, like the aync
PDP-10s and pretty much anything designed by Cray. Maybe it's
interesting because of its historical influence like with the GE645
or the PDP-7. So the experience of using it is one of the least
significant factors in it for me. Not to say it's negatively correlated.
Some of my fondest memories are of low level stuff on PDP-11s,
but most of the machines I'd love to add to my collection are ones
I've never had any experience with at all.
> Does this make sense? Since fewer folks are using assembly or machine
> language, does this account for the indifference to modern hardware?
For me, the "modern hardware" in the sense of PCs are uninteresting
because they fail all the tests for interestingness. The architecture
is something only its mother could love. But it's not so far out in left
field that it's interesting in its own right. While the Intel and AMD
guys have done a bang-up job squeezing performance out of a
turnip and I'm sure some of the chip level details are interesting,
the design of the overall machines is singularly boring. Now some
people might think there is some significant historical value in the
PC per se, but I've got to say I see it just as another step on a
road toward smaller and smaller devices that will eventually approach
the ubiquitous computing model Xerox talked about a while back.
I can't honestly say that I see much intellectually interesting about
the fact that it put computers in the hands of the masses. Sure it
lets more people do more with them and I can now keep in touch
using e-mail with people I couldn't 20 years ago, but I don't find
that an interesting subject of study.
It's kind of like the web. When things first started happening, one
could recognize it as basically as networked, graphical 3270. The
only thing that really seemed different and original was the fact that
now the recipient was responsible for the format of the information
instead of the producer (by virtue of HTML being a markup language
not a layout language). But then people came along and made
everything a table whether it was tabular data or not. "I don't care
how wide your browser window is; these have to be next to each
other." Then came style sheets and we lost the one thing that
was really interesting, the chance to see what would happen
with the one major change to the printing press model. So now
the web is just another mass medium driven by advertising.
It became less interesting as it became more "useful" and
"friendly."
If you've been skimming to see what the punch line is, it's
this. My question is always, "Is it interesting as an object
of study?" not "Is it interesting as a tool to use?"
As always, YMMV
BLS
--- Jim Beacon <jim at g1jbg.co.uk> wrote:
>
>
>
> > aliensrcooluk at yahoo.co.uk wrote:
> > > I surf using my Sega Dreamcast (games console
> > > launched in 1998 in Japan, and 1999 for UK and
> USA)
> > > and I use the Dreamkey 3 (European) browser
> > > which is based on DreamPassport 3 (the
> > > Japanese browser). When altering it they
> > > left some things in, so when I reply to emails
> > > via the POP3 software they are all encoded
> > > in the Japanese character set (ISO-2022JP),
> > > as Don pointed out.
> >
> > Heh heh, that's sufficiently bonkers that I thin
k
> I can live with it ;-)
> >
> > cheers
> >
> > Jules
> >
> The only oddity here, is that opening the message
> tries to load JAVA (I have
> it for some other applets......). I guess most
> people have JAVA disabled.
>
> Jim.
>
Yeah, I have been told something like that
before. I guess it's triggered by having the
email encoded in ISO-2022JP?
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
--- Don <THX1138 at dakotacom.net> wrote:
> Jules Richardson wrote:
> > aliensrcooluk at yahoo.co.uk wrote:
>
> [snip]
>
> > ps. Any ideas why your emails to the list (and
> nobody else's) appear in a
> > larger font than normal? Not sure if it's just
> affecting Thunderbird here or
> > various other people's email clients too!
>
> ISO-2022JP character encoding
>
Sorry, I'll explain...
I surf using my Sega Dreamcast (games console
launched in 1998 in Japan, and 1999 for UK and USA)
and I use the Dreamkey 3 (European) browser
which is based on DreamPassport 3 (the
Japanese browser). When altering it they
left some things in, so when I reply to emails
via the POP3 software they are all encoded
in the Japanese character set (ISO-2022JP),
as Don pointed out.
Apologies if this bugs anyone, but I don't
have a PC, my Amiga doesn't have a modem
nor enough memory to surf the net (only has
2MB at the moment) and, whilst I can read,
delete and move emails via my mobile phone, I
can't reply to emails :(
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
--- Ethan Dicks <ethan.dicks at gmail.com> wrote:
> On 8/26/06, aliensrcooluk at yahoo.co.uk
> <aliensrcooluk at yahoo.co.uk> wrote:
> > --- Chris M <chrism3667 at yahoo.com> wrote:
> > > --- Ethan Dicks <ethan.dicks at gmail.com> wrote:
> > > > If you attempt a read larger than 8-bits on
an
> > > > odd-boundary, the 68000 traps... (Guru
> Meditation)
> > >
> > > Like a blue screen?
> > >
> >
> > No, a Guru Meditation has a completely black
> > screen with a rectangle in white/grey at the
> > top of the screen.
> > Inside the rectangle is a message a long the
> > lines of "A fatal software error has occured.
> > Press mouse button to reset", followed by
> > 2 8 digit (hexidecimal?) numbers.
>
> I think what the OP meant was functionally like a
> blue screen on an MS
> OS, not visually identical to one
Ahh, yes. I have never had the pleasure of
seeing the blue screen on an MS OS, the
computers at work generally freeze up
completely.
>
> In any case, the entire screen may or may not be
> black, depending on
> the nature and severity of the cause - with some
> errors, the entire
> screen was slid down enough to make room for the
> Guru Meditation box,
> which had a blinking red border and red text insid
e
> (red it fatal,
> yellow if not, but that was rare). There _could b
e_
> a "Software
> Failure" requester box with "press mouse button to
> reset", but that
> was _prior_ to a Guru Meditation screen, not the
> Guru Meditation
> itself.
>
> > The first one is the error code, typically
> 80000001 or 80000003,
>
> Those are examples of 68000 trap error codes...
> 80000003 in particular
> happens to be the odd address trap that started
> things off (it was
> rather common, especially if your code went off in
to
> the weeds and
> tried to execute an instruction on an odd-byte
> boundary).
>
> There were also _lots_ of error codes that could
> tell you specifics
> about what really went wrong, but unless you had t
he
> Rom Kernel Manual
> (RKM) handy or did a lot of development, people
> ignored the numbers.
>
> > but I don't know what the 2nd number represents
.
>
> Either "HELP" in ASCII (0x48454C50) or the address
> of the process that
> was running when the machine puked. It was only
> useful if you were a
> developer and used it to fire up ROMWack (an
> internal debugger) to
> sift through the remains of your process to see wh
at
> it was doing when
> something went wrong. Mostly, though, the second
> number wasn't
> particularly helpful.
"ROMWack is an internal debugger", do you
mean it's stored internally (ROM) and can be
accessed when things go wrong, or is it some
external program that can be run to see whats
wrong?
That could be useful if I could use it as I have
some games/software that sometimes causes
it to Guru, even after pluggin in my 4MB
RAM PCMCIA card to give my Amiga 600 a total
of 6MB of memory.
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
I've used a lot of different systems, but some stick in my mind as being
particularly wonderful and others are but a dim memory.
I've used DEC equipment (VAX 730 and 750), but never at an assembly or
machine instruction level--there was simply no need. Unix is unix and
everything's done in C at worst. So I don't remember much about the
hardware and have no particular fondess or aversion to a system--it was
just a box. If it broke, you called for field service; the peripherals
were likely made by someone else, so even those weren't special. They were
like my toaster--they did what they were purchased to do and when they
didn't, there was someone who would fix them. Learn the right Unix
invocation, know where to plug in the cables; after that, it's just a
matter of putting the right software on it.
On the other hand, there are many systems that I've programmed at the
assembly level and have even developed hardware for that I remember quite
well. Some of these were notably inferor to the DEC systems, but they
occupy a fond spot in my mind.
What I'm wondering is if one's feelings about "collectable" systems have
more to do with the level of exposure to the internals of the hardware than
with any intrinsic novelty of the hardware itself.
Does this make sense? Since fewer folks are using assembly or machine
language, does this account for the indifference to modern hardware?
Cheers,
Chuck
On 8/26/06, aliensrcooluk at yahoo.co.uk <aliensrcooluk at yahoo.co.uk> wrote:
> --- Chris M <chrism3667 at yahoo.com> wrote:
> > --- Ethan Dicks <ethan.dicks at gmail.com> wrote:
> > > If you attempt a read larger than 8-bits on an
> > > odd-boundary, the 68000 traps... (Guru Meditation)
> >
> > Like a blue screen?
> >
>
> No, a Guru Meditation has a completely black
> screen with a rectangle in white/grey at the
> top of the screen.
> Inside the rectangle is a message a long the
> lines of "A fatal software error has occured.
> Press mouse button to reset", followed by
> 2 8 digit (hexidecimal?) numbers.
I think what the OP meant was functionally like a blue screen on an MS
OS, not visually identical to one, in this case, the answer is,
"sorta-kinda-mostly", at least from the standpoint that it was the
last thing you get to see before resetting the machine.
In any case, the entire screen may or may not be black, depending on
the nature and severity of the cause - with some errors, the entire
screen was slid down enough to make room for the Guru Meditation box,
which had a blinking red border and red text inside (red it fatal,
yellow if not, but that was rare). There _could be_ a "Software
Failure" requester box with "press mouse button to reset", but that
was _prior_ to a Guru Meditation screen, not the Guru Meditation
itself.
> The first one is the error code, typically 80000001 or 80000003,
Those are examples of 68000 trap error codes... 80000003 in particular
happens to be the odd address trap that started things off (it was
rather common, especially if your code went off into the weeds and
tried to execute an instruction on an odd-byte boundary).
There were also _lots_ of error codes that could tell you specifics
about what really went wrong, but unless you had the Rom Kernel Manual
(RKM) handy or did a lot of development, people ignored the numbers.
> but I don't know what the 2nd number represents.
Either "HELP" in ASCII (0x48454C50) or the address of the process that
was running when the machine puked. It was only useful if you were a
developer and used it to fire up ROMWack (an internal debugger) to
sift through the remains of your process to see what it was doing when
something went wrong. Mostly, though, the second number wasn't
particularly helpful.
> There is also a "recoverable error", which
> gives you a Guru Meditation screen, but with
> a message similar to "A non-fatal error has
> occured. Press mouse button to continue".
> However, apon pressing said mouse button you
> can continue.... for about 5 seconds until
> the same Guru screen pops up, so you end up
> having to do a warm reset anyway!
Yeah.... typically, if you got a recoverable error, something was
likely to happen shortly thereafter that wasn't recoverable.
-ethan
Hi,
I need to get a freight/crater to pick up a
cabinet in Cincinnati OH, palletize and wrap
it so that I can have it picked up for shipping.
Can anyone recommend a company there? Could you
email me off list?
Thanks!
Brian
(this is OT: it's vintage computing stuff!)
--- Chris M <chrism3667 at yahoo.com> wrote:
>
>
> --- Ethan Dicks <ethan.dicks at gmail.com> wrote:
>
> > If you attempt a read larger than 8-bits on an
> > odd-boundary, the 68000
> > traps. Not the same as a halt - you are free to
> > install a trap
> > handler, but in practice, machines like the Amig
a
> > just went through an
> > error dump (Guru Meditation) when low-value CPU
> > traps triggered.
>
> Like a blue screen?
>
No, a Guru Meditation has a completely black
screen with a rectangle in white/grey at the
top of the screen.
Inside the rectangle is a message a long the
lines of "A fatal software error has occured.
Press mouse button to reset", followed by
2 8 digit (hexidecimal?) numbers. The first one
is the error code, typically 80000001 or 80000003,
but I don't know what the 2nd number represents.
If you get a coloured screen on boot-up
(eg. grey, dark grey, blue etc.) then the Amiga
has halted the self test due to a hardware
failure of some sort. You would also see the
Caps Lock LED blink a few times aswell. The
colour shown when it freezes along with the
Caps Lock LED flashing is used to work out
what the problem is.
I can post up more details if you are interested?
There is also a "recoverable error", which
gives you a Guru Meditation screen, but with
a message similar to "A non-fatal error has
occured. Press mouse button to continue".
However, apon pressing said mouse button you
can continue.... for about 5 seconds until
the same Guru screen pops up, so you end up
having to do a warm reset anyway!
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
Hi Glen,
I read in ClassicCmp forum that you have operating system files for
HP1660A, but I couldn't find them in forum.
Is it possible to send me operating system files for HP1660A?
(Or to send me link which to use for thise files download)
I have to use logic analyser but there is a problem with it , which
requires device to be flashed.
Thank you in advance!
Best Regards
Gergana Buchvarova
Engineer SW Validation
Johnson Controls Electronics Bulgaria EOOD
14 Todor Aleksandrov Blvd.
BG-1303 Sofia
Phone: + 359 2 9306418
Fax: + 359 2 9306462
Does anyone within a reasonable driving distance of Poughkeepsie, NY
have any Allied-Telesyn mini-transceivers they don't need? I can throw
a few bucks into the deal to make it worth your while. Thanks.
Peace... Sridhar
I sent my original reply to that poster offlist, but since there's some
interest in this, have a look at my page at:
http://mysite.verizon.net/rtellason/w4s.html
which lists a number of parts that I have a *lot* of. Any of you folks want
some of these, feel free to contact me offlist...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
> Well, the other choice at the time was the 68000. 32-bit registers,
> yes, but it had goofy quirks all its own (didn't you halt the CPU if you
> attempted to read memory not on word boundaries or something?
On the original 68000, instructions had to be aligned on 16 bit boundaries
or you'd get an instruction fault.
The associated stupidity was wasting a bit of the branch range by NOT having
the branch target word-aligned.
> Jules Richardson wrote:
> Well if the IBM PC hadn't turned up, surely computers would have ended up in
> the hands of the masses anyway? There were plenty of good, robust, expandable
> systems with good software support worldwide at the time - all it needed was
> for society to be ready to accept 'the computer' on a wider scale. IBM just
> happened to be in the right place at the right time, and it's unfortunate that
> they'd built a turkey :-)
I agree. Whether it was Apple or IBM or Tandy or someone else, it would
have happened anyway. If I had my 'druthers though, what ended up in
the hands of the masses would have been more of a real appliance than
something to be viewed as a computer. When you get right down to it
the main differences among a game console, a dedicated word processor
and a "personal computer" are the expectations of the user. Nothing
wrong with giving the masses a toaster that can transform into a mixer.
But when you foist on them a device that they need a class at the local
community college to learn "how to use" then you've done a disservice
to both the masses and to the computer scientists.
To bring this back to the collectibility question, there have been a few
machines that seemed to be pitched in that direction. But they never
seemed to generate the momentum that "we've got these at work; I'll
buy one for home" did. A collection of those would make a nice niche
display in a computing museum.
BLS
Hey, all:
I've been thinking it'd be a good idea to buy and set aside some spare
parts for the couple of DEC machines I have around... mostly 7400-series
ICs, some switching transistors and such. It's been a while since I've
bought parts, however. What places (preferably online) have you had good
experiences with?
-O.-
Hans Franke wrote:
> Am 24 Aug 2006 11:50 meinte Don:
>
>> Hi,
>>
>> I've a Sharp PC-1211 with CE-122 "Printer & Cassette Interface".
>> But, I'll be damned if I can figure out how to make the printer
>> *work*! It advances paper when manually commanded to do so.
>> But, I can't figure out how to get the 1211 to print *to* it!
>
> Try
>
> LPRINT "All your Printers belong to us"
I've tried PRINT and LPRINT -- in all four "modes". No luck.
>
>Subject: Re: PDP-8 /e/f/m memory
> From: "Ethan Dicks" <ethan.dicks at gmail.com>
> Date: Wed, 16 Aug 2006 12:13:16 +1200
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 8/15/06, vrs <vrs at msn.com> wrote:
>> From: "Ethan Dicks" <ethan.dicks at gmail.com>
>> > OK. Is a DEC005 OMNIBUS-friendly? We used them on our Qbus COMBOARD,
>> > so that's the context I think of them in.
>>
>> Interesting question, even though I'd never design in a DEC005. They are
>> made of even more unobtainium than the regular tranceivers!
I have a selection of DEC0XX parts on hand from my days in the mill.
>Agreed. I have a few, but I used to make Qbus cards. For most folks,
>the only source is other cards.
Or plain TTL. LS241 is a good reciever for Q, U or Omnibus (Schmitt inputs)
and 74LS38 makes a good open collector driver. There are others.
Allison
So, I have an older USR Total Control system with quad V.34 modems on each
card, and prolly 12 cards in the system.
I was curious as to just what makes this sucker tick, so I pulled a card &
started looking at chip numbers...
Each "modem section" has:
an Intel 80C186 (same chip as in the Tandy 2000) - except they're rated for
20Mhz...
a TI/USR DSP chip, which is prolly useless outside of the intended use
2 each 32Kx8 static ram chips,
4 each 128Kx8 static ram chips
and lots of other 8/16-bit 74-series buffer chips & whanot.
So, *if* I can get a Dynamic-RAM -> Static RAM converter board designed for
the CoCo, I could upgrade 4 CoCo3s to 512K with each modem board.
Anyone have any use for some 20Mhz 80C186's?
Laterz,
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers
zmerch at 30below.com
What do you do when Life gives you lemons,
and you don't *like* lemonade?????????????