<PROM, or maybe one of those TI PALs with the 74-series numbers'. I said
<'No, I can do it with a normal 16 pin TTL chip that doesn't have to go
<in
<a programmer first'. So, what was the chip ?
<
<74LS138, 1 of 8 decoder, the three inputs go to A, B, C, all 8
<possibilities decoded on the outputs.
< Jack Peacock
How about 74153 or 74155 real handy for creating complex miniterms that
a small prom or pal might be used for.
Allison
<> =============================================================guide rai
<> +
<> +
<> +
<> +
<> +++++++++++++++++++++++++++ <<<<<<<direction of motion (96 needed)
<> ^ +
<> | +
<> / +
<> | +
<> |=============================================================guide rai
<> ^optos to read the leading edge of the card for column clock, spacing
<> is such that each one is obscured as the column is over the column
<> leds making it self indexing. It's possible to go very fast.
<
<Now that I like!. I wonder where I can find some cheap photodiodes.
<
<What about one of the CCD (or similar) linear image sensor chips? They're
<quite cheap in surplus shops now, I think... A bit of optics to focus the
<image onto the sensor, and a bit of electronics to drive it (which is not
<that hard to design).
CCD needs a fair amount of electronics, photo transistors are cheaper and
simpler. Jade, JAMCO, JDR and BG micro list phototransistors pretty
cheap.
Allison
>(Cautiously, looking around). Is all the nastiness over, now?
Been over for weeks. It seemed to merely be 'growing pains.'
>Does anyone have the disks for the paint program that came with the Apple
>Koala pad?
I remember hearing that it should work with any app that supports mice.
Glad to have you back. (I was wondering where the heck you were.)
Tim D. Hotze
(Cautiously, looking around). Is all the nastiness over, now?
Does anyone have the disks for the paint program that came with the Apple
Koala pad?
Thanks
manney(a)lrbcg.com
> > panel monitor used an octal keypad & display, and the octal thinking
carried
> > over to the assembler package. Heath also used "split octal" in the
fashion
> >
> Actually I think Octal is a dumb idea for 8 or 16 bit processors :-) -
A side note...on the IMSAI front panel the address/data switches came in
two colors, red and blue, so you could group them for hex or octal
inputs. (Obscure trivia, the prototype IMSAI used black switches.) You
could tell just by looking at someone's front panel if they preferred
hex or octal. Mine is in hex, S/360 Assembler was the first assembly
language I learned, and it was in hex.
If I recall correctly, Microsoft was an early user of split octal. Soon
after the 4K/8K BASIC, MS came up with an editor/debugger package for
Assembler that used the split octal notation (fuzzy here, does anyone
else remember that package, it was short-lived).
Octal proved useful in suprising ways. On Seymour Cray's CDC 6000
series, with a 60 bit word, you might think that a dump using 15 hex
digits per word would be the most useful, but in fact that was never
done, because the 60 bit word was broken down into 15 and 30 bit
instructions (multiple instructions per word, a Cray innovation I
believe), easy to see in octal but not a good fit in hex. Plus, the
character set normally used was 6 bit, not 7 or 8 bit ANSI.
Jack Peacock
-Matt Pritchard
Graphics Engine and Optimization Specialist
MS Age of Empires & Age of Empires ][
> -----Original Message-----
> From: Jeff Kaneko [SMTP:Jeff.Kaneko@ifrsys.com]
> Sent: Wednesday, April 22, 1998 9:37 AM
> To: Discussion re-collecting of classic computers
> Subject: RE: The PC's Soviet?
>
>
> >
> > There were all kinds of small Apple cloners around, with various
> Apple
> > variety and fruit names ("Granny Smith", "McIntosh", "Pear", etc.).
> The
> > only obvious differences between most of these machines and an
> actual
> > Apple ][+ was the lack of the Apple logo, and usually the presence
> of
> > lower case display (though not necessarily the shift-key mod, which
> my
> > machine lacks). Some had additional stuff, though, like function
> keys and
> > slightly differently shaped cases. Or maybe a different colour of
> > plastic.
>
> I fondly remember an issue of BYTE from long ago, that was the April
> 1st edition, that had a phoney advertisement in it for a 'Lemon
> Computer' that looked suspiciously like an Apple ][ (with a rather
> distressed and dissheveled user scratching his head . .).
>
> Wasn't that Creative Computing?. Back in the late 70's they would do
> an "April fools" section of their magazine. One year they printed it
> upside down at the back of the magazine so if you flipped it over, it
> looked like a different magazine.
Have you considered doing this for acoustic delay lines?
Actually, I was thinking about making an emulator that would use
.WAV files instead of .T64 or whatever.
>too. However, I could generalize and say they were all DOS-based,
>written in Pascal or assembler, don't come with source code, have
>poor documentation, etc. and I want to roll my own in straight portable
C.
>I'd rather make it general to handle old S-100 tapes, C-64 tapes, etc.
>instead of just hard-coding one flavor. It should be ready in
>the year 2010.
>
Don't bet on it. I have a book that predicted quality software by
1990. Seriously, though, I don't think collectors are in danger of
making their hobby worthless by saving too much. I doubt you will see
an "extra" C-64 in 2010. They will all be in the hands of collectors
or landfills.
>rescue old data. Sure, QuickCams are nearly disposable now. Cheap
>$1,500 PCs include them these days. Five years from now, they'll be
>embedded in cheap monitors. Ten years from now, they'll be in cereal
>boxes. Unless the hobby of collecting computer junk is adopted by
>Hollywood stars, I humbly suggest that it will be at least *more
difficult*
>for you to find spares for your original equipment than it will be
>for me to find something that could deliver a bitmap by looking
>at my punched card. :-)
>
>- John
>Jefferson Computer Museum <http://www.threedee.com/jcm>
>
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
>> If not the schematics themselves, then how about a database indicating who
>> has what? Users could submit a list of what they have, and others could
>> search it for needed contacts.
That's a pretty good idea... maybe store machines, related hardware,
whether the user has manuals for the machine or not, other notes etc...
It's a shame though about the copyright situation; I try to store binary
images of everything that I can in the hope that I can recreate boot
disks etc. in the event of problems, but it would be nice to be able to
share those freely with others...
(I suppose the danger with this, as with anything on the 'net, is that
we end up with thousands of people all trying to do the same thing and
end up with the current situation of knowing that the information is
probably there *somewhere* but spending years finding it...)
cheers
Jules
>
On Apr 22, 16:08, Philip.Belben(a)powertech.co.uk wrote:
> Subject: Re[2]: PDP 11/23 help needed
> Seth and Pete were discussing the PDP11-23...
> ISTRT the F11 processor is settable between 18 and 22 bit
I forgot -- there's a bit in SSR3 that sets 18/22. You're quite correct about
that.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Apr 22, 16:08, Philip.Belben(a)powertech.co.uk wrote:
> Subject: Re[2]: PDP 11/23 help needed
> Seth and Pete were discussing the PDP11-23...
>
> >> 2) Same as above, but for the M8044-DB boards. I could put one
> >> of these in with the M8047's to get a full 64Kword of RAM, yes?
> >> Does anyone know what the DIP-switch settings for these boards
> >> are?
> >
> > Yes, but I'm not sure why you say "full" and 64Kword" together :-)
> > 32KW (64KB) is the limit for 16-bit addressing, or 128KW (256KB) for 18-bit
> > addressing. Ignoring the I/O page, that is.
>
> Um... Am I way out here? Doesn't the 23 support 22 bit addressing? And
> I never before heard of a 16 bit Qbus! ISTRT the F11 processor is
> settable between 18 and 22 bit (128KW, 256KB and 2MW, 4MB respectively).
> The 18 bit setting is used in the 23 on 18 bit Qbuses and in the 24 on
> unibuses. The 22 bit setting is used on 22 bit Qbuses, but you need
> extra hardware to use it in the 24 (i.e. on unibus).
An 11/23 only supports 18/22-bit addressing if it has the MMU chip fitted,
which
almost all do, though it was, strictly speaking, an option (at least, for most
of the 23's life).
Early KDF11-A's (Rev.A) only support 18-bit, most (Rev.C) support 22-bit
addressing -- iff they have the MMU. Otherwise, they can only access 16-bits
of
address space. I don't recall any setting to change that, you just only get 18
bits in an 18-bit backplane. If you try to access beyond that range, you get a
bus error. ISTR that the ODT still works (always 18-bit) without the MMU,
though. I can't easily check as the only one I have running ATM is a 22-bit
system.
A number of KDF11-A's were fitted to 11/03's as upgrades, and those had 18-bit
backplanes. The 11/03, however, only had a 16-bit address range, as did early
core, MOS RAM, and ROM boards. I wasn't referring to the bus as 16-bit, but to
the address range.
For slightly different reasons, you can't use an MSV11-D (or several other
options) in a 22-bit system. It will fit in the backplane, and work fine, but
it effectively turns the whole system into 18-bit, because it doesn't decode
BAL18-21, and therefore responds to sixteen blocks of addresses.
For similar reasons, the RKV11-D is not often used in 18-bit or 22-bit systems,
since it can only perform DMA with 16-bit addressing (you can access the
registers in an 18- or 22-bit system, of course, because it responds to the
BBS7 signal). There are lots of other I/O options with similar restrictions.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
