I just got an Amstrad ppc 640, and am starting to realise how much I really
wish this thing had a hard disk - even a little one. Is there ANY sort of
hard disk solution that will plug into a 720k 3.5inch floppy controller?
Ideally it would come out the other end in IDE, and I could put one of those
little 1.8 inch 20 meg IDE drives in the thing. Speed is not a huge concern,
since this is a 4.77mhz XT class machine.
Also, if anyone has a wrecked ppc 512 or 640 that has a good back case section-
the bottom part of the main body that the handle is screwed to (and the handle)
I'd be very interested in buying it. Mine appears to have gotten squooshed in
shipping and had the handle torn off, and I'm lothe to trust epoxied plastic
to hold a 14+ pound computer.
--
Jim Strickland
jim(a)calico.litterbox.com
-----------------------------------------------------------------------
Vote Meadocrat! Bill and Opus in 2000 - Who ELSE is there?
-----------------------------------------------------------------------
Well, it is apparent that lots of people would like those HP150 boards I
have. So...
How about the interested people submitting bids for the things? Make the
bids as silly and insulting as you want, just remember, buyer pays
shipping (probably three bucks)!
William Donzelli
william(a)ans.net
Weelll, I can't lurk on this one.
Zane, is your record from Norlin Company? If so, it is the (quite
rare) demo record that Norlin put out when they bought Moog music
>from Bob (Moog). I have archived several of these demos, Moog and
ARP and Oberhiem. Be careful if you play it, they weren't on the
best vinyl.
Zane and Bruce: The Moog Modular Synths were just that... a
collection of modules of various kinds that one ordered to assemble
a complete system... kinda like DEC stuff. There were standard
configs available, but you could add-on, mix-match, whatever.
The particular instrument I am priveleged to share my studio with
is a Model 55 IIIC+ , and was owned by the late Paul Beaver, who used
it to make most of the strange sound effects for a small, obscure
movie in the late 70s called "Star Wars" or something like that.
More detail on them can be found by doing a websearch on "musical
instruments, electronic, Moog"... or one can got to
www.synthfool.com for a good set of links.
ObCLASSICCMP: One of my intentions for at least one of my PDP11
systems is to interface it to my Moog, and obtain an old copy of
Csound or the like.. to recreate an exact environment from the
'childhood' of electronic music.
My collection and studio: www.lightsound.org. The site needs
updating, but you can see the specs for several classic synththesizers.
Cheers
John
ps: Kennedy 9300 parts / svc manual wanted... Enquire Within.
A few questions about clean(ing) circuits:
a)Can dust cause any damage to a PCB? Can it short anything?
b)What do you recommend for cleaning out PCBs if there's lot of it,
or spiderwebs, mold whatever?
c)Does distilled water cause rust?
d)Can distilled water be used to clean circuits?
e)As I understand, tap/spring/rain/etc. water is full of minerals
and that's why it's conductive as well as rust-causing
f)A while ago, I picked up a bunch of 5.25" diskettes, which I hardly
allowed to dry before I put them into the plastic box. Now I
looked inside, and mold is spreading from the Microsoft Assembler
diskettes onto the Apple II ones. What is safe to use to clean
the mold (it's reeely disgusting!)?
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< The first S-100 computers did not come with any termination but they
< soon found that the long bus lines were causing ringing and false
< triggering in the circuits. Ringing is caused when a signal reaches the
< of an unterminated (open) line such as a data buss.* The signal reverse
< polarity and travels back in the direction that it came from just like a
< echo. When it reaches another end, it changes polarity and direction aga
< Now you have two positive pulses and one negative pulse where there is o
< supposed to be one pulse! Consider the number of times that each line
< branched off to a card socket and you can understand that now there wher
< dozen or more echos on every line and they were all at different times.
< It's no wonder that the systems where so difficult to make work with al
< the noise on the buss.
This is true. All signals on the bus and off it obey Transmission line
theory. IT's also the one of the reasons why the T-connector for thin
eithernet must be on the back of the machine and not a 3ft jumper away.
One of the design rules that ALtair bused the worst and IMSAI seemed to
have a clue on was what are clalled stubs. What this translates to
is anything going onto and off of the backplane(bus) MUST be buffered
as close to the edge connector as possible.
< board. I believe that the later S-100 systems like the N* Horizon came w
< termination built into the MB. The ringing problem in the early Altair
No it didn't and doesn't need it. They approached it a bit different
by making one end of the bus a permanently resident IO section with
seria, parallel and heartbeat interrupt. Their choice of drivers and
recievers helped some too. Obeying stub theory was another step taken.
It is good enough that even at 8mhz z80 it works.
< was made worse by use of the long wires that ran from the MB to the fron
< panel. Better designs eliminated a lot the sources of the ringing. FW
that was the horror I saw when I built my altair back when. As an
RF/analog engineer I could see that making my day pure hell. It
proved to be true. The solution was a small board that plugged in and
buffered all the signals to and from the front pannel.
< this is EXACTLY the reason that you still have to terminate SCSI busses
< disk drive cabling. There is still an ongoing debate in the SCSI communi
< about the nessecity/benefits of active vs passive termination.
SCSI is an open collector bus so you need both termination (any) and
it must pull up unused lines or it don't work. This is also true for DEC
Omnibus, Unibus and Qbusses.
One of the long standing problems with bus terminations is that they
absorb power. This required stiffer drivers at the source and since
stiffer drivers matched the bus impedence even worse it tended to make
problem grow rather than solve it. it also consumes power contributing
heat to the box. S100 bus was one of those we made it that way but, no
one ever would have engineered it that way. All of the engineered buses
are terminated in some way or designed to perform without the need for it.
Allison
>Date: Sat, 25 Jul 1998 00:23:07 +0100 (BST)
So, can a standard XT controller be used for 8" drives?
>
>For reading 8" disks, of course. My PC/XT on the desk here has 2 each
of
>360K 5.25" drives, 720K 3.5" drives and 1.1Mbyte 8" drives (double
sided,
>double density, 77 track). Pity the controller I've got has problems
with
>single-density operation. I really must fix that sometime, but it's not
>urgent, as my PERQ has a much nicer floppy system...
For once, I used the correct terminology :) Compared to SCSI, all
IDE controllers and most non-IDE/SCSI MFM drives require very little
configuration. That's what I meant.
>What? ST506 drives (I assume that's what you mean - MFM is an encoding
>system, not a controller interface) have drive select jumpers at least.
>And often other ones.
>
>And the original IBM XT hard disk controller (later version only?) has
a
>set of jumpers to select the drive type. I believe you can solder a DIP
>switch in place of them if you want.
>
So does this mean 1.2MB floppies use a lower bps than 360K disks?
Which controllers were these? I ought to watch out.
>I've seen some controllers that can't correctly handle the 300kbps data
>rate (produced by putting a 360K disk in a 1.2Mbyte drive turning at
>360rpm). Of course the so-called manuals don't mention this anywhere,
but
>it was obvious from a logic analyser on the Write Data pin during
>formatting that it was actually using 250kbps.
>
Where can the connectors be gotten cheaply? I've seen them for a
couple of bucks each. I really ought to perform some maintenance.
Is there anything I need to know, or can I just snap those connectors
on and trim the cable?
>That problem is trivial to solve if you can crimp IDC connectors. Why
do
>people persist in refusing to modify PC parts - even cables?
>
>-tony
>
>
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-----Original Message-----
From: classiccmp(a)u.washington.edu <classiccmp(a)u.washington.edu>
To: Cgregory <Cgregory>
Date: Friday, July 24, 1998 5:56 PM
Subject: Re: Epson QX-10, CP/M
<snip>
I have a complete (I think) set of manuals for the QX-10, so I will offer to
be a source for looking up material and/or copying parts/pages.
>> I'm obviously a neophyte at CP/M and wrestling at this time with a Dec
RB
>> which is even more confusing cause it also runs MSDOS.
>
>The Rainbow is a unique case because of its dual processors.
>
In addition I have QX-10's big brother, the QX-16 which is also a dual
processor machine. Kind of neat being able to boot into either MSDOS or
C/PM.
Cliff Gregory
cgregory(a)lrbcg.com
>Yes with any current printer just like a PC, though the connector may
>be different.
What I mean is, can I transfer files to a PC via the Centronics
interface? Can I 'print' a file in wordstar with the other end of the
cable plugged into a null modem?
>Sure!
Will an apple //c read CP/M disks? How?
I can't use an editor because it would take me forever to cut and paste
the lines between them. You don't realize how limiting the situation
really is. The library never intended this to be used for e-mail. Right
now I'm using Netscape 4 on a T1 connection at a place where I
volunteer.
>Max, get an editor. Either that or don't use LYNX for mail, try elm
>or pine.
>
>Allison
>
>
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>If
>you look on the back of the power supply itself you will see IBM's
>declaration that it should be only used with model 5140 (in several
>languages!).
Yes, there it is. "CAUTION! Indoor use only. To be used only with IBM
MOdel 5140." It never occured to me there would actually be some
valuable information in the disclaimer!
Tom
--
Sysop of Caesarville Online
Client software at: <http://home.earthlink.net/~tomowad/>
< 3/4 of an inch to small to even fit a 2.5" drive. I vaguely recall
< seeing something about 1.8" drives? Am I hallucinating here or does
suc
< a creature exist?
Even smaller...HP made a 1.3" disk drive, Hawkeye ???, I think it was
either 20MB or 40MB capacity. The components were so small you needed
watchmaker tools to take the drive apart.
Jack Peacock
