On Mon 14 Sep 1998 21:56:40, Mark <mark_k(a)iname.com> wrote:
] The other week I bought an IBM 4869 5.25" floppy drive. This is an external
] unit that hooks up to a PC via a 37-way D connector. The case is massive,
] ...
Hope you didn't pay much; I have three of these available on my
"for trade" web page. See this URL:
http://www.cs.unc.edu/~yakowenk/classiccmp/fortrade.html
I'm in NC, zip code 27514 (for those of you calculating postage).
Cheers,
Bill.
Mostly, there are some motherboard design difference between the two.
However, it is known that you can actually swap the boards between the
two if you preferred one case over another and have a bad unit. There
were at least 4 different board revisions, so some boards may not move
to another case. Another thing you might notice is the power supply
connector is different. There was a connector redesign between the newer
(aka 'flat C64') and older (aka 'Breadbox') C64's. The flat 64 has a
square connector where the breadbox 64 has a round one. The flat 64 also
has a different component layout due to IC consolidation. Maybe those
newer chip designs are what's overheating your system. Or it could be
the fact that the parts are closer to the outside of the case.
I'm toying with the idea of swapping boards in my systems. I only heard
that it can be done. I want a functional version of each and I have 2
working flat units and 7 dead breadboxes (of which I salvaged parts from
to get an SX-64 working). For my display units, I would like one of each
design in working order.
Hope this helps,
Jeff Salzman
>I was wondering, what is the difference between a regular Commodore 64 and a
>64C? I've got one of each, and everything seems identical other than that the
>64C looks like a 128. (Well, one other difference is that the 64C overheats
>after about an hour or so...)
>
Popular science used to be a good magazine, until they changed
editors a few years ago and it became much less informative.
While before they had some real journalism, now it's just constant
articles about 'the new superplane'.
>On Thu, 10 Sep 1998 sethm(a)loomcom.com wrote:
>
>> > Is anyone interested in the Popular Science review of the Lisa?
I've
>> > stumbled across that particular issue and if any one is interested
I'll
>> > get it scanned and uploaded.
>> >
>> > colan
>>
>> I'd love to see it! Thanks for letting us know.
>>
>> Next to old computers themselves, my next favorite collectible is
>> classic computer collateral -- ads, catalog entries, old photos,
>> that kind of thing.
>
>I like this kind of stuff, too.
>
>We actually have a large pile of Popular Science magazines that are
slowly
>degrading in the basement. We were going to throw them out, so I got
busy
>with a razor blade and cut out a lot of things. Unfortunatley that got
my
>father and I reading the old issues, and as a result they still haven't
>been thrown out. But I do have a binder full of interesting
>computer-related stuff.
>
>The single-system reviews I've collected from Popular Science are:
>
>Apple ///
>Xerox 820
>Timex Sinclair 1000
>Apple Lisa
>Epson QX-10
>Access
>Kaypro 10
>Gavilan
>Macintosh
>Sinclair QL
>Acorn (unknown model, it's just called the Acorn in the article, looks
> like BBC-B)
>Kaypro 2000
>Amiga
>Atari 520ST
>Macintosh Plus
>
>A lot of other computers are mentioned (and photographed!) in articles
or
>mini-reviews, including:
>
>Sinclair ZX80
>VIC-20
>TRS-80 Pocket Computer
>Sharp PC-1211
>NewBrain
>TRS-80 Color Computer
>TRS-80 Model III
>IBM-PC
>NEC PC-8001A
>Osborne 1
>APF Imagination Machine
>Casio FX-9000P
>TI-99/4A
>HP-86
>Sony SMC-70
>Olivetti M20
>Commodore BX256
>Zenith Z200
>Commodore Max
>Astrocade
>Altos
>Cromemco
>.
>.
>.
>(the list is lengthier than I want to type ;) )
>
>There are also ads for things like the TI-99/2 with Bill Cosby, the
Adam,
>the PMC-80, Ohio Scientific Challenger, Atari 400, Color Computer with
>Isaac Asimov, VIC-20 with William Shatner, etc, etc, etc...
>
>Lots of cool articles on computer technology stuff, too.
>
>If you cut up Popular Science magazines and condense them to just the
>computer stuff, you end up with a really interesting read. :)
>
>> -Seth
>
>Doug Spence
>ds_spenc(a)alcor.concordia.ca
>http://alcor.concordia.ca/~ds_spenc/
>
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
< >Or a 11/780
< >equipped with a DECterm100 (bit mapped and the map is vax resident)?
<
< Didn't this get called a VAXstation-I. If it's the device I remember it
< one (several) Unibus cards and a fibre optic connect or was this somethi
< different again?
Thats the beastie, I've used it too. Not bad for it's day.
Allison
On Sep 14, 16:11, Sam Ismail wrote:
> On Mon, 14 Sep 1998, James Willing wrote:
>
> > As I recall, (going a little out on a limb here) you are correct on the
J2
> > connector. That was to support an Apple marketed numeric keypad. And,
I
> > believe that the other switch (along with cutting the marked pads)
enables
> > lower case encoding.
> >
> > Which of course does little good on an Apple II / II+ with standard
ROMs.
>
> True. You still needed to acquire (or burn) a character ROM with
> lowercase characters.
A few years ago, I made the mod and created a suitable character set ROM
image, which I burned into a 2716. If anybody wants it, you can pick up
the ROM image at
http://www.dunnington.u-net.com/public/NewCG
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
>You're making some of it up. DOS intercepted the command line input and
>only parsed out DOS commands. If it didn't recognize a DOS command it
>passed the line off to BASIC. His DOS enhancement COULD have converted
>any lowercase command line to uppercase before passing it on to BASIC so
>it wouldn't puke.
That's the way I interpreted his description of the action.
>That's entirely doable and would be rather elegant.
Except what's the purpose of the hardware lowercase modification if
the first thing you do with it in software is convert to uppercase? :-)
The only software that I extensively used on a Apple II that dealt with
lowercase characters was Paul Lutus's _Applewriter II_. A very excellent
editor, with what amounts to almost "regular expression" search and
replace. If only EMACS (Eight Megabytes and Continually Swapping?
Escape-Meta-Alt-Control-Shift?) were as lean and mean!
Tim.
>
> The other week I bought an IBM 4869 5.25" floppy drive. This is an
external
> unit that hooks up to a PC via a 37-way D connector. The case is massive,
for a
> simple floppy drive.
>
The extra space (length) is the power supply. I also have one of those
drives.
> Anyway, I can't get it to work properly. It is probably a 360K drive
mechanism,
> and my PC (Philips 386SX AT clone) boots normally with this type of drive
set
> in the backup RAM.
It was made to work with the XT, plugging into a special port on the disk
controller card. Yes, it is a standard 360K drive.
>
> I can format disks and use DIR, but reading or writing any files always
gives
> an Abort/Retry/Cancel error. Unsurprisingly, cleaning the heads made no
> difference. Actually, to elaborate on this copying a load of files to a
newly-
> formatted disk gives an error after copying (say) the first two files.
>
> Does this drive have some non-standard pinout, different from the 37-way
D
> 5.25" port on the back of the PC, or maybe only work with IBM PS/2
machines?
>
The D connector goes directly to the disk drive.
> If it is just faulty, what might the problem be? The cable is unlikely I
think,
> as is the power supply.
>
> The casing has a couple of tamperproof Torx screws. I'd like to know what
size
> they are so that I can buy a suitable screwdriver bit.
Tamperproof screw solution: a SHARP 1/2" drill bit. Just drill off the
heads, and you'll have no problem.
The drive that I had, I had no use for, and couldn't get it to work with my
PC, so here's what I did:
-Pulled the old 360K drive, and replaced it with a 1.2 meg drive.
-Cut a hole in the top of the case large enough so that I could attach a
3.5" drive on top of the 5.25".
-Super-glued the 3.5" to the 5.25" drive.
-Split the power cable, and put a 3.5" floppy connector on it so that the
P/S could power both drives.
-Using a TRS-80 printer cable (ribbon - type), I twisted the cable and put
on new plugs to connect the floppies.
-Ran the ribbon cable under the P/S, and out a slot that I cut in the back.
-Connected all cables, and put the case back together.
-Ran ribbon cable into open slot on back of computer and connected to
floppy connector.
It may seem like a bit of work to get an external drive, but it sure beats
buying a new $80 tower case.
--
-Jason
(roblwill(a)usaor.net)
ICQ#-1730318
I'm picking as I've been around long enough in the industry to see what I
call retrorevisionism. It's the terminology creep that has been occuring
since the PC became the computer for all things. Though its been going on
for load longer.
< I don't know why you would want to class that as a MPU. Most of these
< terms were invented because a new breed came into existance and it neede
< a new name to distinguish it from what came before. "Microprocessor"
< was coined to celebrate a logic integration landmark: a computer on a
< single chip.
the terms were invented after the fact.
< > < Microcomputer: a computer based on a single microprocessor.
< >
< > What if there are several performing different tasks in the same box.
<
< OK, Microcomputer: a computer that runs applications on a single
< microprocessor.
Lessee, my visual 1050 uses the 6502 for video and a z80 for the main cpu
and a z80 for the MFM hard disk controller (all running concurrently).
Teh single cpu thing is a sticking point.
Try: A computer based on microprocessors.
< I really don't know what to call a SMP PC, though. Microsupercomputer?
Or the s100 4 z80 loosely coupled SMP running CP/M2.2... Terminology
sorta gets mashed.
< > < Workstation: a computer designed to run Unix with a bitmapped displa
< >
< > What if it's a VAX running VMS? Yes the VS3100s were definatly
< > workststions.
<
< OK, Workstation: a computer with a bitmapped display designed to run a
< non-Microsoft multitasking OS.
;') a NON PC pc.
< > < Minicomputer: a timesharing computer that can support fewer than 10
< > < simultaneous users.
< >
< > VAX and minicomputer that could and often did have more than 100 users
<
< OK, Minicomputer: a general purpose computer without a memory-mapped
< display, smaller than a mainframe.
What about a MicrovaxII servicing a half dozen Xterms? Or a 11/780
equipped with a DECterm100 (bit mapped and the map is vax resident)?
Minicomputer: something significantly smaller and cheaper than mainframes
of the time. The definition was based on compact size not IO interface
or the presence or lack of a bit mapped display.
< > < Mainframe: a timesharing computer than can support 100 or more user
< > < simultaneously.
< >
< > Generally big iron and most that had that distinction where physically
< > large. AKA univac 1180.
<
< OK, Mainframe: a general purpose computer without a memory-mapped displa
< that weighs at least one ton.
Oh dear.. the video displays on some of the big ums... Actually the break
point was again size and especially cost. At the time mini and mainframe
were in vogue the difference was around 10/1 in cost and around the same
or greater for weight.
< Some people use PC's as dedicated controllers, but that doesn't make
< a PC an embedded computer in my mind. Cross-development seems to be th
< only common factor when people talk about embedded, although there are
< embedded environments, such as QNX, that support native development.
PDP-8s and 11s were some of the mainstays for embedded controls work
and some had local resources enough to develop insitu. Your viewpoint
is influenced by the current vogue. ***An embedded system is simply a
system that has a computer (ANY!) burried/coupled to it.*** It could be
a NC mill with a PDP-8, a production line with a PDP-15 or in later years
a PLC or a process control system with a s100 crate and Compucolor board
and color CRT. I have seen and worked on all of these and more.
Allison
I have a small (about 2"x2") box which has a 30 pin edge connector
on one end and a switch on the other. There is a label on one side
with says:
ON OFF
"THE PILL"
This came in a box of misc Atari 800 items but I don't know where
it would plug into an Atari. Anyone have any idea what it might be?
-----
David Williams - Computer Packrat
dlw(a)trailingedge.com
http://www.trailingedge.com
