From: robin on 7 Jun 2010 10:35
"Yannick Duch�ne (Hibou57)" <yannick_duchene(a)yahoo.fr> wrote in message news:op.vdxjxcnqule2fv(a)garhos...
>What is a "drum memory" ?
It's behaves like a conventional disc in a disc drive.
Only instead of a set of platters bolted together and rotating
on the spindle formed from the bolt,
it's a cylinder rotating around its axis.
In the case of the disc drive, the surfaces of the platters are
coated with film capable of being magnetised.
In the case of the drum, the outside surface is coated with the magnetic film.
From: Yannick Duchêne (Hibou57) on 7 Jun 2010 10:56
Le Mon, 07 Jun 2010 16:35:39 +0200, robin <robin51(a)dodo.com.au> a écrit:
> It's behaves like a conventional disc in a disc drive.
> Only instead of a set of platters bolted together and rotating
> on the spindle formed from the bolt,
> it's a cylinder rotating around its axis.
> In the case of the disc drive, the surfaces of the platters are
> coated with film capable of being magnetised.
> In the case of the drum, the outside surface is coated with the magnetic
OK, I see, a kind of Jurassic mass storage device (seems there was funny
things in these times.. still clever for that time technology, I confess
with due respect).
There is even better than a pragma Assert: a SPARK --# check.
--# check C and WhoKnowWhat and YouKnowWho;
--# assert Ada;
-- i.e. forget about previous premises which leads to conclusion
-- and start with new conclusion as premise.
From: Martin Krischik on 7 Jun 2010 11:07
Am 07.06.2010, 14:35 Uhr, schrieb Yannick Duchêne (Hibou57)
> What is a “drum memory” ?
From: Richard Harter on 7 Jun 2010 11:24
On Mon, 07 Jun 2010 06:40:07 -0400, Peter Flass
>> "Martin Krischik" <krischik(a)users.sourceforge.net> wrote in message news:op.vdv17504z25lew(a)macpro-eth1.krischik.com...
>> | Am 06.06.2010, 17:19 Uhr, schrieb J. Clarke <jclarke.usenet(a)cox.net>:
>> | > On 6/6/2010 12:25 AM, Shmuel (Seymour J.) Metz wrote:
>> | > What do you believe to be the difference between machine code and
>> | > assembler?
>> | 6502 Assembler:
>> | LDA #10
>> | 6502 Machine code:
>> | A9 10
>> | Any more silly questions?
>> That assembler was of a much later period than the one under discussion,
>> namely, the 1940s-1950s.
>If you want to talk *really* old assemblers, look at SOAP. The hardware
>had no core, only drum memory, and each H/W instruction contained the
>drum address of the next instruction to be executed. A big function of
>the assembler was figuring out where to store the instructions on the
>drum so that the next instruction was under the R/W head just as the
>previous finished executing -- based on the instruction timings. Try
>doing that by hand for a large program!
It must be time to recall the story of Mel. I've got a copy on
my website at http://home.tiac.net/~cri/2001/mel.html though I am
sure that there must be other copies on the web.
Richard Harter, cri(a)tiac.net
Reality is real; words are real too.
However words are not reality.
From: Fritz Wuehler on 7 Jun 2010 12:18
> Of course that's effectively two programs - a macro processor and an
> assembler. The PL/I preprocessor isn't tied to the language and can be
> used as a general-purpose macro processor.
The IBM assembler macro processor *is* part of the assembler and *is*
tightly bound to the language.