<The PIC is a lot older than most people think - I seem to recall that the
<16C54 was first produced by GI (before they became Microchip) in about
<1979. Of course there have been many new devices since then.
Earlier and it was the cp1600 series (I think '77). GI was heavy in the
embedded market then and used in the intellivison game to name one. I
knew of them as they were down the block from me when I lived on LI(NY).
<Similar, but not the same. Most copies are 'illuminate for white', most
<laserprinters are 'illuminate for black'. This means the corona wires are
<at different voltages, amongst other things.
Not as much as your expect. I worked with both the 3300 copier and the
printer version (XP12/24) and same for the Ricoh 1040(40ppm). It was
coincidence we had both in the group so copier repair was a common
task and not in my basic training. ;)
<Also, the scanning in a photocopier is entirely mechanical, and is (in
<general) synchronised mechanically. Laser printers have a lot of
<electronic sync stuff, things like the laser beam detect sensor, the
<registration shutter, etc.
Like I said different optics.
<Still, understanding a copier is a good starting point for understanding
<a laser printer. Just expect there to be a lot of changes.
The packaging of of the optical system is where the differece are
significant but a basic understanding of electrophotography is in order
and the xerox texts does cover reverse printing (uses reversed relative
electrostatic bias). FYI: when training the trainer I stopped a smart
ass FSE cold by tweeking the bias so everything was reversed. Took him
4 hours to swap everthing and not fix it.
Actually, the 486 had different things that made it different from the 386.
There's the math-co-processor (DX only), the .8 micron design, (on DX/2 50
and above only), as well as a built in floating point. There's also the ZIF
socket on MOST (but not all) 486 motheboards, as companies were using their
own designs, some with integrated chip, others with this and that, etc.
Tim D. Hotze
From: jpero(a)cgo.wave.ca <jpero(a)cgo.wave.ca>
To: Discussion re-collecting of classic computers
Date: Saturday, January 31, 1998 5:34 AM
Subject: Re: 486 vs 386 (was Development, round II)
> >And you'll have to pardon my ignorance of the Intel parts after the 8085,
> >but why wouldn't a 386 work if the 486 works? (Other than the speed
> >difference.) It has always been my impression that few OS's/applications
> >need whatever extra software features that differentiate the 486 from the
> I believe the 486 was supposed to be just a 386 with a built-in math
> co-processor. Then Intel came out with the 486SX. Which was really just a
> broken DX, a 486 in which the built-in math co-processor didn't work.
> -- Kirk
Not very much difference but 486 is really ahead in getting more of
performance usually runs at least 1 cycle per instruction.
The 386dx excutes instuctions all over the map between 5 and 15
(guessing). Example: 386dx/387 33mhz bit slower than 486dx 25.
Remembering from years gone by in clone/brands world...
First, before I'm done, for clock to clock cycles, 286 and 386 is no
better at excuting instructions most of time usually but buyer opted
for XT's and 286's because Intel was asking Too Much for 386, the
387 chip actually cost 2k at that time. This is why 386 is
sooo late becoming popular when win 3.1 came out. At that time, in
late 91s loads of users were still on XTs and we upgraded them to
either 286 boards (286/20mhz PcMate yuk!) and once in awhile series
of 386sx or rare 386dx for other upgrades. Within short time later
about half a year boatloads of 386dx 33/40 and few 386sx thrown in
now and then were sold for either pc and upgrades when the price is
After 93-94ish, things lost their luste n' fun then became very
common thing. (yawn) while we sold long series of 486 machines
then P5 ever since. I have NOT remembered how CHEAP, useful real
and good pc anywhere or when til now. 1~2k CDN gets you *VERY*
decent complete P5 or PII machine with 14" color monitor now. I'm
kicking PS/1 original 2011 because it has no hd and too little ram
and it did sport 1k price tag but!
That old days is very interesting time indeed!
Pero, Jason D.
At 08:27 PM 1/30/98, you wrote:
>portable and an EPROM eraser for $100. I bought another new that
>interfaces to a printer port for $25 at a hamfest.
Hey, I'm going to the Charlotte, NC Hamfest in March. Maybe I'll pick one
At 02:08 PM 1/30/98 -0800, you wrote:
>If you want to build your own, find the 4-volume set of _Ciarcia's Circuit
>Cellar_ (or find the corresponding late-70's issue of _BYTE_) and look
>at some of his designs.
Heck, if I could do all that, I wouldn't be asking about them. :) I never
got into electronics too much, just one class in high school, and I have
big clumsy hands when it comes to soldering irons.
But thanks to everyone for providing information on this subject. Who
knows? Maybe once I get a programmer, I'll start burning my hands again. :)
IIRC they started officially calling it Warp with V2.0, the first release following the Microsoft/IBM breakup.
From: Kip Crosby[SMTP:firstname.lastname@example.org]
Sent: Friday, January 30, 1998 10:40 AM
To: Discussion re-collecting of classic computers
Subject: Re: Re: Development, round II
At 12:34 1/30/98 GMT, you wrote:
>BTW What is Warp? Is it the OS/2 windowing system? If so, why would I
>want to use it at all, let alone on a 286? ;-)
Warp is OS/2v3. You couldn't use it on a 286, but if you had, say, a
486/33 -- do pardon me for mentioning a nine-year-old part -- it would
begin to be worth playing with. My copy of Warp is still very much to
hand, and I think anyone who can scrounge up an appropriate computer should
run it (for a while) if they have the opportunity, because it's a real
Kip Crosby, honcho, mechanic and sole proprietor, Kip's Garage
http://www.kipsgarage.com: rumors, tech tips and philosophy for the trenches
Coming Spring '98: The Windows 98 Bible by Kip Crosby and Fred Davis!
<There are _very_ few good books on laser printers - and the manufacturers
<do NOT supply decent technical manual in my experience. I found a book at
<a charity shop (thrift store?) called 'Electrophotography' that gives a
Copiers are the same technology save for the imaging systems. I should
know I had an engineering finger in every laser printer with a DEC label
starting with the LN01 (Xerox XP12) through the 2250 series and my
specialty was the over 8PPM Ricoh engines.
At the thrifts they are always priced at $50. or greater. The Adam is three
pieces, and two of the pieces are on the large size. Those doing the
pricing at the thrifts seem to equate size (and number of pieces) with
price, so these systems tend to be priced higher than average. If you want
one and can find one locally for $50 or less, then you should probably grab
it. You can find them advertised on the net for less, but the shipping
costs will kill any savings.
BTW, don't make the mistake of leaving the printer behind if the pieces
happen to be priced separately. The power supply for the computer is in the
printer so you need it to power the system. Also the data tapes are
non-standard and are becoming harder to come by.
From: classiccmp(a)u.washington.edu <classiccmp(a)u.washington.edu>
To: Cgregory <Cgregory>
Date: Friday, January 30, 1998 3:43 AM
Subject: Re: Point Four, Anadex, C-64 questions
>At 08:36 PM 1/29/98 -0800, you wrote:
>>> Also, what's a fair price for a Coleco Adam system: 2 keyboards, memory
>>> box with datacassette drives, external numeric keypad with knob
>>> and printer.
>>$25 - $30 as long as it works.
>I have to disagree here... I'd say $50-75, possibly as high as $100 with
>the extra parts, depending on how badly one wants one. (Again, assuming
>it's working.) Mind you, that's what I'd feel comfortable selling it,
>wihtout feeling like I'd ripped someone off. I don't know if I'd pay that
>much right now, but catch me in a good month...
Ya, that was the IBM PC Convertible. There's a picture of one with the
printer attached at
> -----Original Message-----
> From: PG Manney [SMTP:email@example.com]
> Sent: Friday, January 30, 1998 5:14 PM
> To: Discussion re-collecting of classic computers
> Subject: Re: Interesting Find
> (Sharp PC-7100)
> > Notice how the handle can slide towards the back so it's off-center?
> > Notice the little metal inserts along the top edge of the back? There's
> > printer (I've only got one) that attaches to the back for portability.
> Didn't the IBM Portable (or convertible...whatever) do that?
From: Joe <rigdonj(a)intellistar.net>
Subject: More stuff
> Also got a strange Commodore cable. It has what looks like a double
> ended HP-IB connector one end and a card edge connector on the other. All
> the connectors have 24 contacts. Both ends have a heavy braided ground
> strap. It looks like it's about 2 foot long. Any one know what this is
That is a PET to IEEE-488 cable, used to interface Commodore IEEE-488
Printers, Modems and Disk Drives to the PET/CBM, B-128 or P-500 series
computers. They are getting hard to come by so if you think you may get
a Commodore PET/CBM/B/P computer one day I would advise you hang onto
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