>
>Subject: Re: Homebrew Drum Computer
> From: Jules Richardson <julesrichardsonuk at yahoo.co.uk>
> Date: Fri, 14 Dec 2007 08:19:06 -0600
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Robert Nansel wrote:
>> Certainly I could trash a few old cassette decks, or even get some
>> floppy R/W heads to experiment with audio recording tape super-glued to
>> a soda can, but I really want to get at least the performance the old
>> machines could produce, so that means a reasonably fast drum RPM,
>> somewhere around 6000 RPM, say.
>
>Very interesting project. Won't standard tape heads only work reliably if the
>magnetic material's passing by at quite a narrow range of speeds, though?
>Google suggests that's 1 7/8" per second, which isn't very fast at all - a
>drum that can do a few tens of RPM seems possible, but 6000??
Correct, there is a relationship between gap width and media speed.
I've used casette heads to 10ips but above that there are problems.
one is the total inductance of the winding limit the upper frequency
reponse (used as saturation recording head) to around 40khz and thats
pushing it.
Allison
>
>If I've got my numbers right, a small 6" drum has a diameter of approx 19" and
>at 6000rpm will take 1/100 seconds to do a single revolution. That's 1900" per
>second past each head - roughly 1000 times the typical operating speed of a
>cassette deck.
>
>Build several low-speed soda can drums - equivalent in number to the word
>length of your machine, then read/write data in parallel... (OK, that's a
>humourous suggestion, but it wouldn't surprise me if someone hasn't tried it)
>
>cheers
>
>Jules
> My main component storage is a set of interlocking drawers arranged in a
> block about 4 feet wide by 3 high. Some drawers are square-fronted
> (about 1.5" sq) and some are double-width. The resistors are in
> double-width drawers, with two E12 values per drawer. First row is
> 10/12 ohm, 15/18 ohm, 22/27, 33/39, 47/56, 68/82. Next is 100/120, etc,
> then 1k0/1k2, etc, and so on up to 680k/820k, then the last row is
> assorted "1M to 8M2", "10M and over", "less than 10R", "high wattage",
> and things like that. For E24 and closer-tolerance values, I just put
> them in the drawer that's got the nearest-matching label. Capacitors I
> have squeezed into 1 row, one decade to a drawer, and a couple of bigger
> drawers for larger electrolytics. The really big ones are in a box
> elsewhere.
So spookily similar I'm now very very worried ! or perhaps its a British
thing.
> To give an example of how the ICs are stored, there's a drawer for "LS00 -
> LS80" or thereabouts, with the lower end of that range stored in the
> front and the upper half in the rear section of the drawer. So there
> are 4 or 5 drawers for each logic family. Two places I used to work had
> one drawer per type but that's overkill for my collection.
One drawer for 2-4 types for Ic's Transistors diodes.
Mike
> Message: 6
> Date: Thu, 13 Dec 2007 06:12:19 -0800 (PST)
> From: Mr Ian Primus <ian_primus at yahoo.com>
> So, now I think I need to actually, finally organize my parts. You see, I
> started to do this a long time
> ago, and I have a lot of those little plastic drawers. I got about as far
> as the basic parts, and half way
> through the electrolytics. Everything else is semi-sorted into drawers,
> albiet with rather vauge
I set up some of those drawers years ago (more than 25, eek) resistors and
caps sorted by value, Ics transistors diodes by type #.
I was in small scale production and the system seemed to work well enough.
Untill recently I had a couple of regular products for customers who shipped
in parts so they had a set of drawers for themselves and a very basic stock
control system on an Excel spreadsheet. No longer in production but still
have the drawers, a pain to set up but many years ago, but I can find most
things I want in seconds.
> Otherwise, you'll spend two hours just trying to find that 330 ohm current
> limiting resistor you need.
Thats why I set it up.
> about - how bad is it to store IC's in those clear plastic parts drawers?
> Any problem with static?
> What about CMOS chips?
A lot of my personal stuff is older 74 flavours, that does not seem to
suffer static problems, Cmos is kept in antistatic foam or those black a/s
carriers that the I/c's are shipped in. I have a whole box full of empty
carriers if somebody wants them. I'cs shipped in A/s tubes are kept in tube
untill used.
The system has served me well over the years, a bit anal maybe but it worked
for me.
Mike
SEBHC - the Society of Eight-Bit Heath Computerists - has become a
Google group. If you are interested in the H8, the H89, the better half
of the H/Z100, or the ETxx trainers, please come join us. We maintain an
extensive archive of Heath 8-bit software, both HDOS and CP/M, as well
as a large collection of hardware and software documentation.
This is a great group which includes several ex-Heath employees as well
as others deeply versed in the workings of these computers.
The group is closed in the interests of sanity and to protect the
archive; if you're interested come to
http://groups.google.com/group/sebhc?lnk=gschg and request membership.
Jack
No virus found in this outgoing message.
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11/27/2007 8:30 PM
-------------- Original message ----------------------
From: Richard <legalize at xmission.com>
>
> OK, with my new Origin 2000 machines, I was thinking that I could use
> these SGI drives+sleds that I had purchased previously, where the
> seller said they would work in Onyx2/Origin machines. However, while
> the sleds appear compatible, the drive interface is not.
>
> Is there any online guide that compares the different drive sled
> designs for SGI machines so that I can compare what's being offered on
> ebay to identify the machines that can use it?
>
> For instance, my drives have a high density connector that is only
> about 1" long, but the Origin 2000 has a high density connector that
> looks to be about 2-2.5" long.
>
> Is my only recourse to scrape through individual manuals to try and
> find diagrams?
> --
> "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
> <http://www.xmission.com/~legalize/book/download/index.html>
>
> Legalize Adulthood! <http://blogs.xmission.com/legalize/>
Hi Richard
The ones I have seen take standars SCA drives ????
Power and data in the same connector ??? The Connector is a little more
rugged looking. same as a Later Sun.
- Jerry
Hi,
I recently bought a KayPro II keyboard. It contains a nice Keytronics
mechanical keyboard and really nice case. I'd like to convert it to a
parallel ASCII keyboard or just reuse its case but was wondering if anyone
had the schematics?
Please let me know if you have the KapPro II keyboard schematics. Thanks!
Andrew Lynch
LisaEm 1.2.0 is available for download right now, from the usual place:
http://lisaem.sunder.net/downloads.html
Many LisaEm users have complained that ROMs are too difficult to
extract. The new version of LisaEm solves this by allowing you to run
with out a ROM. If you wanted to try LisaEm, but couldn't because you
didn't have ROMs for it, now you can!
It emulates the functions of the Lisa Boot ROM as well as the Dual
Parallel Card without requiring a ROM, and allows you to boot into Lisa
Office System. If you've felt limited by only having a single
emulated Profile hard drive because you didn't have the Dual Parallel
ROM, the new version also emulates these, without requiring a ROM.
All you need is Lisa Office System and LisaEm.
As this is the first release of this feature, don't be surprised if you
encounter bugs. Please report any unexpected behavior so that I can fix
it. :-)
Additionally, I've added two movies that show how to install Lisa Office
System and MacWorks. (MacWorks still doesn't work properly on LisaEm
however.)
------------------------------------------------------------------------------
Lisa Emulator Change History
http://lisaem.sunder.net/
------------------------------------------------------------------------------
2007.09.19 - fixed romless floppy boot to always boot from floppy and not
switch to Profile.
2007.09.15 - debugging ROMless boot.
new bug: when trying to boot from floppy, if a profile exists
and is bootable, LOS starts up from the Profile instead of the
floppy.
2007.09.09 - David Cecchin's XPM icon in unix
2007.09.07 - added Save/Load PRAM to Preferences
- Quit now closes any open Preference window as well
2007.08.29 - libdc42 macbinii encoded dart to dc42 conversion bugfix
2007.08.16 - added LOS error codes to ROMless error handler
- fix raw screenshot crash
2007.08.13 - got both ROMless boot and ROMless dual parallel card to work
2007.08.06 - individual profile power controls + create new profile inside
a new menu named profile.
2007.07.28 - replaced all exit() and EXIT() calls with messages before
quitting emulator so at least we know what crashed.
2007.07.27 - ROMless works with both profile and floppy now.
- Fixed a bug with configuration saving.
2007.07.26 - Tracelog checkmark correction
2007.07.25 - added Zap PRAM button in main Preferences panel
2007.07.23 - ROMLess booting - floppy works
2007.07.19 - ROMLess booting start
2007.07.12 - RESET opcode supervisor mode bug fix.
2007.07.10 - CPU core tests
If you'd like to support this project, you can do so by sending me
something from my Amazon wish list. (Used books and DVD's are
perfectly fine with me.) The trains are for my kid. :)
http://www.amazon.com/gp/registry/wishlist/14EOBF86ARMDT/ref=wl_web/
Well, I've made lots of progress on the eternal task
of cleaning, sorting and organizing. I can now see my
entire workbench! I found half a dozen #2 Phillips
screwdrivers I hadn't seen in a while, and while
vacuuming, I probably picked up a couple pounds of
screws, wire insulation bits and solder drops.
So, now I think I need to actually, finally organize
my parts. You see, I started to do this a long time
ago, and I have a lot of those little plastic drawers.
I got about as far as the basic parts, and half way
through the electrolytics. Everything else is
semi-sorted into drawers, albiet with rather vauge
categories "Transistors... Diodes..." or completely
unsorted (Salsa jars, butter tubs, shoe boxes, coffee
cans and Altoids tins). So now, I need to sit down,
for a good long day, and sort parts into drawers.
And herein lies my question - how do you manage a
large parts collection? I mean, the phrase "junkbox"
generally referrs to a somewhat organized system of
finding parts, not just a copier paper box full of
parts. Otherwise, you'll spend two hours just trying
to find that 330 ohm current limiting resistor you
need.
So - how do other electronic hobbyists sort parts? How
far do you organize them? A drawer for each value of
resistor? Drawer for a range of values? What works
well, to minimize the time spend searching for
components? Also, another thing I have been wondering
about - how bad is it to store IC's in those clear
plastic parts drawers? Any problem with static? I've
never noticed any, but then again, so far I've only
got a handfull of basic TTL logic sorted out. The rest
are still in tubes and boxes. What about CMOS chips?
So, I'd be interested to hear what other people have
to say on the subject - and Jay, I hope this is
on-topic enough. I mean, these are all parts used for
repairing and maintaining on-topic hardware, so I
think it counts. All of us that fix this stuff need to
keep track of parts. The next time I need a 1488 to
repair a terminal that won't transmit, I don't want to
spend four hours trying to find it.
-Ian
------------Original Message:
Date: Thu, 13 Dec 2007 06:12:19 -0800 (PST)
From: Mr Ian Primus <ian_primus at yahoo.com>
Subject: Semi-OT:Storing electronic parts
Well, I've made lots of progress on the eternal task
of cleaning, sorting and organizing. I can now see my
entire workbench! I found half a dozen #2 Phillips
screwdrivers I hadn't seen in a while, and while
vacuuming, I probably picked up a couple pounds of
screws, wire insulation bits and solder drops.
So, now I think I need to actually, finally organize
my parts. You see, I started to do this a long time
ago, and I have a lot of those little plastic drawers.
I got about as far as the basic parts, and half way
through the electrolytics. Everything else is
semi-sorted into drawers, albiet with rather vauge
categories "Transistors... Diodes..." or completely
unsorted (Salsa jars, butter tubs, shoe boxes, coffee
cans and Altoids tins). So now, I need to sit down,
for a good long day, and sort parts into drawers.
And herein lies my question - how do you manage a
large parts collection? I mean, the phrase "junkbox"
generally referrs to a somewhat organized system of
finding parts, not just a copier paper box full of
parts. Otherwise, you'll spend two hours just trying
to find that 330 ohm current limiting resistor you
need.
-Ian
------------Reply:
Boy, does that sound familiar!
For resistors, I was lucky enough to have a lot of small plastic
boxes that Sprague used to put their caps into; they're stacked
up in a couple of small partitioned cardboard parts bins.
Things like tantalum caps, fuses, hardware etc. I keep in those
small partitioned clear plastic craft boxes.
Diodes and small transistors are in individual small paper
bag/envelopes, which in turn are in small cardboard boxes,
file folder style. You could use the same for resistors & caps.
Bigger parts go into the same partitioned cardboard parts bins
use for the resistor boxes.
ICs I keep loose in drawers, unless I have a lot of one type which I keep
in tubes; a few special MOS ones I kept in foam, but have had a
few go bad with pin rot from a certain type of foam. Just keep the
humidity reasonable.
The problem with semi-inflexible systems like drawers is adding
new items; I finally started a spreadsheet cross-referencing IC
numbers to drawer/compartment so I don't have to worry about keeping
them in any sequence and can also double up, and it also gives me an
idea of what I've got (as long as I remember to keep it current ;-)
mike
The machine is available in Portland Or or preferably, up the gorge in
Goldendale Wa. which is located about 100 miles east of Portland.
The machine could be shipped, but it would require a pallet for the
case, foam for the monitor and separate packing for the drive and boards.
I'm not sure how much it's worth. I have had an offer for $370. So I
guess thats a start.
The system includes the mono hi-res graphics monitor, space cadet
keyboard, full document (user) set, but no hardware prints (sorry)
and a frame tosser board. I'll throw in a couple bus mice, but they will
need to be rewired. I'll fire it up and verify that it still boots. (it
did 6 months ago)
If you pick it up in goldendale, I'll let you dig around in my shed for
other goodies.
The machine is badged as a XL400 but boot reports a XL1200. I assume
it's the extra memory and possibly software upgrades.
It has been stored inside, in a clean dry environment since I picked it
up about 7 years ago.
Jim Davis.
