Re: tiny COBOL, Article on new mainframe use

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Sujet : Re: tiny COBOL, Article on new mainframe use
De : anton (at) *nospam* mips.complang.tuwien.ac.at (Anton Ertl)
Groupes : comp.arch
Date : 02. Sep 2024, 11:38:07
Autres entêtes
Organisation : Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID : <2024Sep2.123807@mips.complang.tuwien.ac.at>
References : 1 2 3 4 5 6 7 8
User-Agent : xrn 10.11
Terje Mathisen <terje.mathisen@tmsw.no> writes:
Thomas Koenig wrote:
[Commodore 1541]
And were extremely slow - around 300 bytes per second, comparable
to a card reader.  But fast loaders could improve on that up to 10 kB/s.
>
They did that by reading every 1/2 sector, then reassembling after 2
rotations, instead of having to wait a full rotation between every
sector read?

No.  The disk-access part of the disk drive was actually pretty cool,
supporting variable data rate with a 6502.  The variable data rate and
group-code recording allowed getting 170KB on a single-sided
single-density disk, while FM disk controllers typically got 85KB, and
Wozniak got 140KB.  I don't remember what was done about sector
interleaving, but when you replaced the slow interface (see below) to
the computer with a fast one (I have Prologic DOS), the drive was up
to 28 times faster.

The problem is in the data transfer between the drive (which had its
own CPU) and the computer.  They replaced the parallel IEEE-488
interface of the PET with a serial interface for cost reasons, and
then they botched the serial transfer.  There were some contributing
factors, like the 6522 bug (the C64 had no 6522, though), and the
desired compatibility with the VIC-20 (which then did not happen
anyway: the Commodore 1540 (for the VIC-20) does not work unmodified
with the C64).

They probably could still have fixed the problem by giving some more
love to the firmware for the computer-to-disk-drive interface;
according to <https://www.c64-wiki.de/wiki/Schnelllader>, the fastest
serial fast-loaders were 15 times as fast as the serial routines in
the firmware.  I guess that, when the C64 was designed, disk drives
were rare for computers with the price of the C64, so it did not seem
that important to make that interface fast.

- anton
--
'Anyone trying for "industrial quality" ISA should avoid undefined behavior.'
  Mitch Alsup, <c17fcd89-f024-40e7-a594-88a85ac10d20o@googlegroups.com>

Date Sujet#  Auteur
14 Aug 24 * Article on new mainframe use132Stephen Fuld
14 Aug 24 +* Re: Article on new mainframe use124MitchAlsup1
15 Aug 24 i`* Re: Article on new mainframe use123George Neuner
15 Aug 24 i +- Re: Article on new mainframe use1Stephen Fuld
15 Aug 24 i `* Re: Article on new mainframe use121MitchAlsup1
15 Aug 24 i  +- Re: Article on new mainframe use1Stephen Fuld
15 Aug 24 i  +* Re: Article on new mainframe use118Niklas Holsti
16 Aug 24 i  i`* Re: Article on new mainframe use117Lawrence D'Oliveiro
16 Aug 24 i  i +* Re: COBOL, Article on new mainframe use30John Levine
17 Aug 24 i  i i+* Re: COBOL, Article on new mainframe use5Lawrence D'Oliveiro
17 Aug 24 i  i ii+- Re: COBOL, Article on new mainframe use1John Levine
17 Aug 24 i  i ii`* Re: COBOL, Article on new mainframe use3Keith Thompson
18 Aug 24 i  i ii `* Re: coroutines in COBOL, Article on new mainframe use2John Levine
18 Aug 24 i  i ii  `- Re: coroutines in COBOL, Article on new mainframe use1Lawrence D'Oliveiro
18 Aug 24 i  i i`* Re: COBOL, Article on new mainframe use24OrangeFish
18 Aug 24 i  i i +- Re: COBOL, Article on new mainframe use1John Levine
18 Aug 24 i  i i `* Re: COBOL, Article on new mainframe use22John Dallman
18 Aug 24 i  i i  +* Re: COBOL, Article on new mainframe use14MitchAlsup1
19 Aug 24 i  i i  i+- Re: COBOL, Article on new mainframe use1John Dallman
23 Aug 24 i  i i  i`* Re: COBOL, Article on new mainframe use12Terje Mathisen
23 Aug 24 i  i i  i `* Re: COBOL, Article on new mainframe use11Michael S
23 Aug 24 i  i i  i  `* Re: COBOL, Article on new mainframe use10Terje Mathisen
23 Aug 24 i  i i  i   `* Re: COBOL, Article on new mainframe use9Michael S
23 Aug 24 i  i i  i    +* Re: COBOL, Article on new mainframe use6John Levine
24 Aug 24 i  i i  i    i+- Re: COBOL, Article on new mainframe use1Lawrence D'Oliveiro
27 Aug 24 i  i i  i    i`* Re: COBOL, Article on new mainframe use4Keith Thompson
28 Aug 24 i  i i  i    i `* Re: COBOL, Article on new mainframe use3MitchAlsup1
28 Aug 24 i  i i  i    i  `* Re: COBOL, Article on new mainframe use2Keith Thompson
2 Sep 24 i  i i  i    i   `- Re: COBOL, Article on new mainframe use1Lawrence D'Oliveiro
24 Aug 24 i  i i  i    `* Re: COBOL, Article on new mainframe use2John Dallman
28 Aug 24 i  i i  i     `- Re: COBOL, Article on new mainframe use1Lawrence D'Oliveiro
19 Aug 24 i  i i  `* Re: COBOL, Article on new mainframe use7Lawrence D'Oliveiro
19 Aug 24 i  i i   `* Re: COBOL, Article on new mainframe use6John Levine
21 Aug 24 i  i i    `* Re: COBOL, Article on new mainframe use5Lawrence D'Oliveiro
21 Aug 24 i  i i     `* Re: COBOL, Article on new mainframe use4Keith Thompson
21 Aug 24 i  i i      `* Re: COBOL, Article on new mainframe use3MitchAlsup1
21 Aug 24 i  i i       +- Re: COBOL, Article on new mainframe use1Keith Thompson
2 Sep 24 i  i i       `- Re: COBOL, Article on new mainframe use1Tim Rentsch
16 Aug 24 i  i +* Re: Article on new mainframe use82George Neuner
22 Aug 24 i  i i`* Re: Article on new mainframe use81BGB
23 Aug 24 i  i i +- Re: Article on new mainframe use1Stephen Fuld
23 Aug 24 i  i i `* Re: Article on new mainframe use79Lawrence D'Oliveiro
23 Aug 24 i  i i  +* Re: Article on new mainframe use77BGB
23 Aug 24 i  i i  i+- Re: libraries, was Article on new mainframe use1John Levine
24 Aug 24 i  i i  i`* Re: Article on new mainframe use75Lawrence D'Oliveiro
24 Aug 24 i  i i  i +- Re: Article on new mainframe use1BGB
24 Aug 24 i  i i  i `* Re: Article on new mainframe use73John Levine
28 Aug 24 i  i i  i  +* Re: Article on new mainframe use70Lawrence D'Oliveiro
29 Aug 24 i  i i  i  i`* Re: Article on new mainframe use69John Levine
30 Aug 24 i  i i  i  i `* Re: Article on new mainframe use68Lawrence D'Oliveiro
30 Aug 24 i  i i  i  i  `* Re: Article on new mainframe use67Michael S
30 Aug 24 i  i i  i  i   +* Re: Article on new mainframe use12John Levine
30 Aug 24 i  i i  i  i   i`* Re: tiny COBOL, Article on new mainframe use11John Levine
31 Aug 24 i  i i  i  i   i +* Re: tiny COBOL, Article on new mainframe use8Stefan Monnier
31 Aug 24 i  i i  i  i   i i+* Re: tiny COBOL, Article on new mainframe use5Thomas Koenig
2 Sep 24 i  i i  i  i   i ii`* Re: tiny COBOL, Article on new mainframe use4Terje Mathisen
2 Sep 24 i  i i  i  i   i ii +* Re: tiny COBOL, Article on new mainframe use2Thomas Koenig
2 Sep 24 i  i i  i  i   i ii i`- Re: tiny COBOL, Article on new mainframe use1Anssi Saari
2 Sep 24 i  i i  i  i   i ii `- Re: tiny COBOL, Article on new mainframe use1Anton Ertl
31 Aug 24 i  i i  i  i   i i+- Re: tiny COBOL, Article on new mainframe use1Anton Ertl
31 Aug 24 i  i i  i  i   i i`- Re: tiny COBOL, Article on new mainframe use1George Neuner
2 Sep 24 i  i i  i  i   i `* Re: tiny COBOL, Article on new mainframe use2Lawrence D'Oliveiro
4 Sep 24 i  i i  i  i   i  `- Re: tiny COBOL, Article on new mainframe use1Lawrence D'Oliveiro
1 Sep 24 i  i i  i  i   +* Re: Article on new mainframe use6Lawrence D'Oliveiro
1 Sep 24 i  i i  i  i   i+* Re: COBOL history, Article on new mainframe use3John Levine
1 Sep 24 i  i i  i  i   ii+- Re: COBOL history, Article on new mainframe use1Lynn Wheeler
2 Sep 24 i  i i  i  i   ii`- Re: COBOL history, Article on new mainframe use1Lawrence D'Oliveiro
1 Sep 24 i  i i  i  i   i`* Re: Article on new mainframe use2John Dallman
2 Sep 24 i  i i  i  i   i `- Re: Article on new mainframe use1Lawrence D'Oliveiro
1 Sep 24 i  i i  i  i   `* Re: Article on new mainframe use48Lawrence D'Oliveiro
1 Sep 24 i  i i  i  i    `* Re: Article on new mainframe use47MitchAlsup1
2 Sep 24 i  i i  i  i     `* Re: Article on new mainframe use46Lawrence D'Oliveiro
2 Sep 24 i  i i  i  i      `* Re: Address bits again, Article on new mainframe use45John Levine
2 Sep 24 i  i i  i  i       +- Re: Address bits again, Article on new mainframe use1Thomas Koenig
2 Sep 24 i  i i  i  i       +- Re: Address bits again, Article on new mainframe use1Stephen Fuld
4 Sep 24 i  i i  i  i       `* Re: Address bits again, Article on new mainframe use42Lawrence D'Oliveiro
4 Sep 24 i  i i  i  i        +* Re: Address bits again, Article on new mainframe use2Terje Mathisen
4 Sep 24 i  i i  i  i        i`- Re: Address bits again, Article on new mainframe use1Lawrence D'Oliveiro
4 Sep 24 i  i i  i  i        `* Re: Address bits again, Article on new mainframe use39John Levine
4 Sep 24 i  i i  i  i         +* Re: Address bits again, Article on new mainframe use37John Dallman
4 Sep 24 i  i i  i  i         i+- Re: Address bits again, Article on new mainframe use1MitchAlsup1
5 Sep 24 i  i i  i  i         i+* transparent huge pages (was: Address bits again)4Anton Ertl
5 Sep 24 i  i i  i  i         ii+- Re: transparent huge pages1MitchAlsup1
5 Sep 24 i  i i  i  i         ii+- Re: transparent huge pages1Chris M. Thomasson
8 Sep 24 i  i i  i  i         ii`- Re: transparent huge pages (was: Address bits again)1Lawrence D'Oliveiro
5 Sep 24 i  i i  i  i         i`* Re: Address bits again, Article on new mainframe use31John Levine
8 Sep 24 i  i i  i  i         i `* Re: Address bits again, Article on new mainframe use30Lawrence D'Oliveiro
8 Sep 24 i  i i  i  i         i  `* Re: Address bits again, Article on new mainframe use29MitchAlsup1
8 Sep 24 i  i i  i  i         i   +* Re: Address bits again, Article on new mainframe use4MitchAlsup1
8 Sep 24 i  i i  i  i         i   i`* Re: Address bits again, Article on new mainframe use3Chris M. Thomasson
9 Sep 24 i  i i  i  i         i   i `* Re: Address bits again, Article on new mainframe use2Lawrence D'Oliveiro
9 Sep 24 i  i i  i  i         i   i  `- Re: Address bits again, Article on new mainframe use1Chris M. Thomasson
9 Sep 24 i  i i  i  i         i   `* Re: Address bits again, Article on new mainframe use24Lawrence D'Oliveiro
9 Sep 24 i  i i  i  i         i    `* Re: Address bits again, Article on new mainframe use23MitchAlsup1
10 Sep 24 i  i i  i  i         i     `* Re: Address bits again, Article on new mainframe use22Lawrence D'Oliveiro
11 Sep 24 i  i i  i  i         i      +* Re: Address bits again, Article on new mainframe use2John Levine
11 Sep 24 i  i i  i  i         i      i`- Re: Address bits again, Article on new mainframe use1Lawrence D'Oliveiro
11 Sep 24 i  i i  i  i         i      `* Re: Address bits again, Article on new mainframe use19MitchAlsup1
12 Sep 24 i  i i  i  i         i       `* Re: Address bits again, Article on new mainframe use18Lawrence D'Oliveiro
12 Sep 24 i  i i  i  i         i        `* Re: Address bits again, Article on new mainframe use17Lars Poulsen
12 Sep 24 i  i i  i  i         i         +* Re: Address bits again, Article on new mainframe use13Lawrence D'Oliveiro
13 Sep 24 i  i i  i  i         i         `* Re: Address bits again, Article on new mainframe use3George Neuner
4 Sep 24 i  i i  i  i         `- Re: Address bits again, Article on new mainframe use1Lawrence D'Oliveiro
28 Aug 24 i  i i  i  `* Re: Article on new mainframe use2Lawrence D'Oliveiro
23 Aug 24 i  i i  `- Re: Article on new mainframe use1George Neuner
16 Aug 24 i  i `* Re: Article on new mainframe use4Lynn Wheeler
15 Aug 24 i  `- Re: Article on new mainframe use1Thomas Koenig
15 Aug 24 `* Re: Article on new mainframe use7Lawrence D'Oliveiro

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