IBM PC-DOS 2.10 explorations

[Will Senn]

Richard,

I'll look for the Compaq 3.31 3.5" image. Thanks!

Will

On 10/4/20 10:02 AM, Richard Cini wrote:
> You can find bootable disk images on-line that self extract to a 
> floppy. For DOS 3.31 I use a Compaq version that went with my 
> DeskPro/386.
>
> I would only emphasize that 3.5” support didn’t exist before DOS 3 (I 
> forget if it was 3 or 3.1; it was when the PS/2 came out). So you have 
> to watch the image sizes.
>
> http://www.classiccmp.org/cini
> Long Island S100 User’s Group
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> ------------------------------------------------------------------------
> *From:* cctalk <cctalk-bounces at classiccmp.org> on behalf of Will Senn 
> via cctalk <cctalk at classiccmp.org>
> *Sent:* Sunday, October 4, 2020 10:52:49 AM
> *To:* Fred Cisin <cisin at xenosoft.com>; General Discussion: On-Topic 
> and Off-Topic Posts <cctalk at classiccmp.org>
> *Subject:* Re: IBM PC-DOS 2.10 explorations
> On 10/3/20 4:07 PM, Fred Cisin via cctalk wrote:
> > On Sat, 3 Oct 2020, Will Senn via cctalk wrote:
> >> 2. Most of the Assembly examples use DOS interrupt 21 for output. Is
> >> this typical of assembly programs of the time, or did folks use other
> >> methods?
> >
> > For simple stuff, Int21H works and is portable to anything running
> > MS-DOS.
> >
> > Int10H is less portable.  Not as commonly used.
> >
> > If you need SPEED, which all commercial software perceived a need for,
> > then you need to determine WHERE video memory is (segment B000H for
> > MDA, segment B800H for CGA, with TEXT modes of EGA/VGA also using
> > those), and put bytes/words directly into video memory.  REP MOVSW was
> > generally the quickest way to put up a screenful of stuff (avoid
> > segment over-ride because REP MOVSW lost that if an interrupt occured
> > in mid transfer)
> >
> Great detail. I'll be playing around in the video memory. Int 21H is
> fine for printf style output, but I've never really played around with
> pages of data and this sounds like fun.
>
> >
> > Keyboard input could be done with Int21H, Int16h, or accessing memory
> > in the BIOS segment.
> >
> >> 3. I was able to find a lot of 5150/5160 and other manuals, but I
> >> couldn't find an IBM Macro Assembler 2.0 manual (there are plenty of
> >> IBM Macro Assembler/2 manuals, but those are for OS/2, not DOS). Does
> >> anyone know where I can find one online?
> >
> > MASM manual??!?
> > MASM 5.0 was the first version to have documentation that a sane
> > person could say was adequate.
> > The MASM 5.00 manualS were pretty usable for the earlier MASM.
> Hmm. I'll give it a shot.
>
> >
> > I used Lafore as textbook for my assembly language class
> >
> >
> >> 4. In y'all's view, what are the significant differences between IBM
> >> PC-DOS 2.10 and it's brother MS-DOS 2.x?
> >
> > 2.00 to 2.10 was minor changes.  Perhaps the most significant was that
> > the PCJr used the QumeTrak 142 (early half-height) drives, which were
> > TOO SLOW for 2.00, so PC-DOS 2.10 slowed down the DOS track to track
> > access time.
> >
> > 2.11 was MS-DOS ONLY, not PC-DOS.  It was one of the favorite ones for
> > OEMs to patch for different video or different drives (such as 720K 
> 3.5")
> > PC-DOS didn't get 3.5" drives until PC-DOS 3.20.
> > PC-DOS 3.30 added 1.4M If you want CD-ROM, 3.10 added the "network
> > redirector".
> >
> > MS-DOS (NOT PC-DOS) 3.31, another favorite for patching, was the first
> > to support hard drives larger than 32M
> >
> > PC-DOS 4.00 was unpopular, partially becaause IBM didn't pre-warn
> > Norton to revise their fUtilities.
> >
> > MS-DOS 5.00 was the first to be sold RETAIL (not gray-market from an
> > OEM), and added such things as SETVER (so LINK and EXe2BIN didn't need
> > patching for DOS versions).
> >
> > MS-DOS 6.00 added a whole cartful of bundled aftermarket add-ons,
> > including compression, SMARTDRV disk cacheing, etc.
> > PC-DOS 6.10 had a cartful of different aftermarket brands of the same
> > add-ons.
> >
> > MS-DOS 6.20 was the first version of MS-DOS for which imporving
> > reliability was primary goal!  (instead of adding smell-o-vision,
> > dancing kangaroos and yodelling jellyfish)
> > It backed off the settings for SMARTDRV so that disks didn't get
> > trashed (incorrectly blamed on compression)
> > 6.21 was same, without compression due to copyright lawsuit(s).
> > 6.22 was same with non-infringing compression
> >
>
> Great detail, thanks.
>
> >> 5. I'm thinking of moving on to 3.3 at some point, in your view, what
> >> are the advantages?
> > Consider 3.31, instead of 3.30, to get larger drive support.
> >
> I am using a Thinkpad T430 w/DOS 6.22. If I can figure out how to get
> 3.31 on there, I'll give it a shot. I bought a Floppy-USB connector for
> my old 1.44 floppy drive and it works fine with DOS 6.22, but I'm not
> sure where to locate 3.31 media that I could burn onto a 1.44 floppy and
> boot. I have sealed IBM DOS 3.3 media, but I don't think my T430 is
> really compatible :). So, I'm not keen on opening the seal...
>
> > Bob Wallace (MICROS~1 10th? employee) wrote the IBM PASCAL.  He
> > advised me to NOT use the run-time library.
> >
> Well, there's a thought. I have Turbo Pascal 3 and it works fine. I just
> like the feeling of running the old stuff.
>
>
> > --
> > Grumpy Ol' Fred             cisin at xenosoft.com
>
> Thanks Fred!
>
>
> -- 
> GPG Fingerprint: 68F4 B3BD 1730 555A 4462  7D45 3EAA 5B6D A982 BAAF
>


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