From: Andrew Davie <adavie(a)mad.scientist.com>
Are there any hard to find extras that I should ask about before collecting it?
I'm now a pdp'er yet (my 23 compatible comes in this weekend) but recent discussions indicate that you should grab *all* ancillary stuff for the dec, especially.... the RT-11 manuals! worth, oh... about.... $1,300.00 ( and if you do, please drop me some email. ;))
- Mike: dogas(a)leading.net
If you have a Macintosh and are interested in DEC Hardware I heartily
recommend the following URL http://www.han.de/~bb/pdp8e/pdp8e.html If
you've not downloaded Bernhard Baehr's PDP-8/e simulator recently it's
gotten REALLY cool. He's added a front panel, that is just to cool for
words :^) For example, when you turn the key to the 'off' position, it
shuts the simulator down. You can flip switches and watch the blinken
lights :^)
Zane
| Zane H. Healy | UNIX Systems Adminstrator |
| healyzh(a)aracnet.com (primary) | Linux Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| and Zane's Computer Museum. |
| http://www.dragonfire.net/~healyzh/ |
<on disk size supported (say number of 256-byte logical sectors), a more
<robust (economical, speedy) disk structure could be developed.
<
<If we allowed a 32-bit logical sector pointer, then 2^32*2^8 bytes could
<be stored. That is 2^40 bytes total. Since 2^20 bytes is 1 Meg, a 32-bit
<logical sector pointer allows 1 megamegabyte. 2^30 bytes is 1 Gig, and
<2^10 is 1024. Therefore, 2^40 bytes is 1024 Gig.
<
<I think a 32-bit pointer would be sufficient for a while. Most drives
<available are under 20 Gig.
Several key items.
Most more recient disks are 512byte sectors.
Even with 16bit pointer using clustering 512k is not unreasonable, though
maybe inefficient.
Using a 24bit pointer and 512b sectors will net 8gb, adaquate.
The problem (pardon my lack of knowledge of the TI Filesystem) is that
simply having a point of some size is only part of the problem. You also
need to have a descriptor for how many sectors are owned by the file in
question. If the file system is a simple sequential one an additional
two or three bytes are adaquate. Generally though a sequential allocation
scheme is inefficient for random file access. A random file access scheme
means multiple descriptors for each block (assuming multipe scetor
granularty). Obviously in that case you can really consume space in the
directory with a desicriptor per block. This leads to FAT or ALLOCATION
style of file systesm (dos and cpm respectively) or something like unix
uses. I'm suggesting that more bits extend greater addressing but impose
other impacts not mentioned.
Allison
At 08:06 PM 1/13/99 +0000, you wrote:
>Now, though, it appears that most sets contain special parts for whatever
>model that set is supposed to build, parts that aren't much use for
>anything else. Seems not to encourage imagination anything like as much.
Depends on what sets you buy. You can buy sets that build one specific
model (though you can of course do whatever you want) or you can buy the
tubs of 1000 pieces for $20. I have been known to buy specific models to
get some odd part that I thought was cool, but generally I'll take the
general purpose models.
Obcc: Yes, you can build computers and calculators from Lego. Any reason
why you couldn't replicate a Digi-Comp with Lego?
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
<<< I've come across enough machines that use 6-bit characters internally..
<
< 6 Bit ? thats new - I never have seen a 6 Bit byte computer - I
< know 6 Bit only from some serial line encodings.
Most common one was the PDP8.
Allison
>I agree that what you propose is a good thing for a kid to have,
>but it's a completely different topic - using the computer as a
>general purpose learning tool, or playing on a computer. What
>we were talking about was playing *with* a computer.
>
>|For programming, I would recommend BASIC, TO START WITH, followed by an
>|introduction to C and assembly as soon as basic principles are understood.
>
>I've yet to see a BASIC that runs on top of an OS that's as
>easy to get into and provides direct feedback as well as a
>graphical BASIC DOS.
Apparently you have not tried Visual Basic...
>
>|Once the kid has gotten thoroughly into it, THEN maybe a birthday present
>|of a set of Linux disks?
>
>Hah. My kids started on Linux, at about 8 and 10. Yeah, I
>intend to (God help me) get a Win or Mac system soon, but
>only because there are too many things not yet available on
>Linux.
>
>But Linux is just fine as a newbie OS for a kid.
At what level are you talking? I have not seen any sofware for kids (like
the knowledge adventure or humongous entertainment series) that would run on
Linux. It is hard to get a kid used to play with windows for 6 years and
tell him that it is crap and the one where you have to type long commands is
a lot better.
>
>-Miles
>
Cameron Kaiser said...
|
|Eight years old and learning PDP-8 assembler? What does she do on the
|weekends, solve differential equations?!? :-)
Actually, any reasonably intelligent 8 y/o who is interested,
and who has learned to enjoy learning, is capable some level
of assembler programming. It's amazing what society and the
schools can do to destroy a young mind.
-Miles
At 06:23 PM 1/13/99 +1, you wrote:
>> The younger the kid, the more they need graphics capability. Teenagers
>> don't really need it, no matter how much they beg for it (they just want to
>> visit whitehouse.com).
>
>I found it just the other way - as younger they are as less
>exact high res and high reality visions they need. An 5 year
Not high quality graphics, just graphics. a 3 year old, for example, who
has yet to learn to read (not Ward, of course 8^), would find a MS-DOS
based computer, for example, pretty useless. Simply because the
combinations of letters has no significance to the kid. Give the kid a
basic mac, however, and the kid can see a picture of the Rabbit from Reader
Rabbit and understand that clicking on it will start the Reader Rabbit
program.
Meanwhile, a 14 year old may not be *happy* with an MS-DOS based XT/AT, but
they can make use of it, writing papers, calling BBSes/internet shell
accounts, writing programs. As I said, your teenager may tell you how much
they need that T-1 and SVGA to write their book report, but they really
just want to access porno web sites. (I speak from experience, having been
a teenager once.)
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
Is there still a source for paper tape and punch cards (new or old)?
Is there also a source for old mechanical ttys? I'd love to get one
connected to one of my Linux boxes!
Arfon
