Subject: Re: Anyone have/know of Persci drives, parts
1. There are no microcontrollers on the 270/277 series drives (I believe
that there were on the later 299 drive)
2. The board has a huge amount of analog circuitry on it, both for the r/w
head and the very complex servo system, and is not easy to troubleshoot.
3. None of the components on the board, including the 50 or so ICs, are
socketed.
No argument that the boards ultimately could be repaired, but it's not
nearly as easy as your post suggests. Plus there are 4 other major but
smaller boards on the drive in addition to the large main board.
> I need some Persci 8" drives (model 270 or 277) and/or parts to repair
them
> for some systems. The part that I need most is the very large circuit
board
> on the right side of the drive. Anyone know of a source? [I'm sure that
Are you actually missing this board? If not, then surely the existing one
can be repaired to component level -- AFAIK the only custom part is an
8048 microcontroller, which presumably could be copied from one in a good
drive (I don;t think the 8048 has any security features).
-tony
I have received an email from a gentleman asking if I can identify
a portable computer that he used to own.
The machines ran DOS (MSDOS), and appears to have a standard PC/XT style
keyboard layout.
It is a "box" machine line the early IBM portable or Compaq portable.
It has a monochrome screen (CRT), somewhat to left of center. Left of the
screen is "open space". To the right of the screen are three 1/2 height
5.25" drive bays running horizontally (on this machine it has a floppy,
a hard drive and what looks like a filler plate). Below the drive bays
there are four "knobs" and what looks like it may be a switch. On the far
right (beside the knobs) it looks like they keyboard cable comes out of a
hole in the front panel.
I have posted the picture he sent at:
http://www.dunfield.com/pub/portable.jpg
Anyone know what this is?
Regards,
Dave
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Hi all,
first I want to thank you for your nice and fast help with
my Commodore Pet ROM
problem. Now I have a little question for my personal
Interest:
There were many Eprom Programmers back when the 2532 etc.
were actual which
were designed for popular homecomputers (I own one for my
Pet too and know
of many for C=64). Many of these devices were "homebrewed
gear" or sold as
kits. But after lots of time googling around I haven't
found much stuff
about this old eproms. Okay, I have at least a bunch of
datasheets and some
schematics where ex. the 2532 were used and learned a lot
of early 1980's
hardware basics :) But I could not find some schematics
(and software) of
Eprom programmers dedicated to this chips. My (maybe dumb)
question: Does
anyone have some schematics and software (would be great)
for a little
homebrewed Eprom Programmer which works with a standard PC
parallel-port or
ISA slot? This would be a great project for rainy winter
days :)
Best Regards,
Wolfgang
====================================================
Ing. Wolfgang Eichberger cell.: +43-664-240-65-92
http://www.eichberger.org
email: wolfgang(a)eichberger.org
----------------------------------------------------
Gruentalerstr. 24 - 4020 Linz ? AUSTRIA
====================================================
Oops
I'd forgot that he already had a place for them.
These directories could use an index though :)
Thanks Al
Later
Dwight
>From: aek(a)spies.com
>
>
>> Maybe Al can make a directory to hold ROM images.
>
>www.bitsavers.org/HP/
>
>
> A few years back when I was a medical student and calling in sick usually
> meant failing a rotation, I got a bad case of bronchitis while on the ENT
> surgery service and ran a fever of 102 F. Naturally, you have to be
> unresponsive and on a ventilator to get off sick (and even then you may
> have to make up the work), so I went in anyway after coughing up half a
> lung's worth of brownish-red phlegm in the sink (and since I was ill and
> fogged on cough medicine, I forgot to wash it down).
>
> That afternoon, I returned to find a trail of ants leading up to the
> loogie in the sink, and a ring of dead ants around it who had tried to
> eat the ball of sputum, failed, and died.
Ants have been known to go after other bodily fluids as well, with varying
results....
Finally found the five minutes to see if my Dragon 64 works. It doesn't.
I get a white screen with a black border (which seems healthy enough),
then in the centre of the screen a few random characters (some with
inverse video). Occasionally after a reset the random characters don't
stay together but occupy random locations toward the middle of the
screen.
I assume (having never seen an operational D32 or 64 before) that it
should say "Dragon 64" or something, implying that character generation
is screwed - but why the random characters should jump positions
sometimes I don't know (unless the design of the reset circuitry is not
very good)
One obvious fault I found was that pin 6 of the 40 pin 6847 IC was
broken and had been badly repaired in the past (such that I don't think
the joint had held), but fixing that hasn't made a difference. The fact
it was ever broken at all suggests that someone's been fiddling inside
the machine though...
I notice IC17 (a socketed 18 pin DIL) is missing - should it be?
None of the DRAM is getting warm (suggesting failure), and the fact that
there's something approaching normality on the display suggest that the
power rails are OK and the CPU's at least operating.
Of course presumably a RAM fault could quite easily explain random
characters and locations though, but doesn't explain the stable white
screen / black border (unless that's done in low level video hardware).
Any ideas? If I can get this thing running then it's another potential
for the CGE show this coming weekend.
cheers,
Jules
I have the following guides available, if there is any interest:
6025000 "Guide to Operations"
6280085 "Guide to Operations - Personal Computer XT"
(Not sure if this is complete, but it has 2 diskettes and some options suppliments included)
6322511 "Guide to Operations - Personal Computer XT" (different than above...)
1502241 "Guide to Operations - Personal Computer AT"
1502491 "Installation and Setup"
(2 charts included)
6280087 "Hardware Maintenance Service"
(2 diskettes included)
6322508 "Technical Reference - Personal Computer XT and Portable Personal Computer"
6025005 "Technical Reference"
6280099 "Technical Reference - Personal Computer AT"
All reasonable offers will be seriously considered.
I believe these are complete (except where otherwise mentioned).
I am willing to provide pictures and/or specific info (within reason) upon request.
I prefer to sell as a set.
thank you,
Dan Hoolihan
hoolihan(a)*NO*SPAM*pacbell.net
