Upon reading http://www.breezer.demon.co.uk/spec/tech/ay-3-8912.html,
I encountered the following: ---
The AY-3-8910/8912 (and derivatives) has found its way into a variety of home
computers and games consoles including the following:
Sinclair ZX Spectrum 128/+2/+3
Amstrad CPC 464/664/6128
Mattel Intellivision
BBC Micro
Atari ST
Sega Master System
---
Well, it's true WRT the Speccy, the Ammy (I suppose you can't say that =) and
the ST, but didn't we establish a while back that the BBC and Master System
chip, the SN76489, while superficially similar, was a different construction.
And as for the Intellivision, perhaps is it just due to the limited system in
general, lack of space, or perhaps a slow driving clock, but with the sub-
mediocre sound of the INTV, it seems like such a waste to employ a more
adanced sound generator such as the AY,
--
En ligne avec Thor 2.6a.
Thank you everybody for the suggestions. Here is how things
finally shook out.
The Pentium machine had a real, 360KB drive in it borrowed from
a PCjr. (I had stated that in the original note.) Formatting
issues between 1.2MB drives and 360KB drives were not part of the
equation.
I tried formating the diskettes (double density, double sided) in
both the 360KB drive on the Pentium and the 360KB drive in the
PCjr. This did not seem to make a difference.
Diskettes formatted and written by the Pentium machine were
usually unreadable in the PCjr. In a few tests they were also
unreadable in a second PCjr. Sometimes I could get a directory
or copy a file, but usually I was getting the familiar
"Abort, Retry, Ignore." A diskette "refresh" utility was reporting
lots of read errors on sectors, some recoverable and some not.
Diskettes written by the Jr were readable on the Pentium.
Old diskettes written years ago were readable everywhere. (These
were written by yet a different drive.)
I deduced that since the Pentium 360KB drive was writing the
diskettes and two PCjrs couldn't read them, that it must be the
Pentium 360KB drive causing the problems. So I swapped it out
and put a 1.2MB drive in it's place. I know about the head width
problems, but would you believe that one of the Jrs was able to
read diskettes created on the 1.2MB drive?
To make a long story short, the 360KB drive in the Pentium was ok,
the 1.2MB drive can write 360KB diskettes that are readable on
the PCjr, and one of the PCjr drives is flakey.
I think I was unlucky in my early testing when both Jrs balked
at the diskettes created on the Pentium. One of the Jrs drives is
know known to be bad, one is confirmed good, and the 360KB drive on
the Pentium is good, yet a diskette created on the Pentium caused
read errors on both Jrs, which led me to suspect the wrong drive.
I've not been able to reproduce that error again.
Now for the bad drive ... If I clean the rails with alcohol and
lube them with silicone spray, it does a slightly better job of
reading foreign (i.e.: not its own) diskettes. Based on this,
methinks that the head is not being positioned exactly where
it should be. However, those rails are pretty clean now and
the problems persist. It's an old Qume drive, 1/2 height.
I'm saving the drive for now, but a flakey 5.25 inch drive isn't
of much use.
And I've also learned that DOS 2.1 does NOT tolerate diskette
errors during the boot process. :-)
Pick up in south-central PA or at VCF East.
IBM 5363 II
In very nice condition and working when decomissioned; it spent all its
life in the server room. I'm pretty certain it hasn't been opened or
changed by anybody, so its probably original specs, but I don't have the
time or interest to power it up and check. It has a 5.25" drive and a
tape drive.
IBM 9331 012 5.25" drive. It appears to have all the cables with it.
two IBM 4869 5.25" drives. These appear to have all the cables with them.
two IBM 5394-01B units. I'm not sure what these are, but they have built
in 3.5" drives.
two IBM terminals, P/N 83X7939. They have DB25 connectors and no
keyboards; I'm not sure I have the cables to hook them up. If these are
incorrect or more pieces are needed, I _might_ be able to get the proper
terminals.
Two Universal Data Systems V.32 modems with very impressive cables.
Two cards that appear new in box, labeled P/N 7363223, in IBM labeld
boxes. They almost look like PCI cards. I haven't the foggiest what
they are or what they go to.
The tape I offered free earlier this week and which nobody claimed fits
in the IBM's tape drive, so it's included, too.
I'd like to get rid of the stuff as one lot, but I'll sell just
peripherals provided there's somebody interested in the 5363. Cash
preferred, but I'll consider a trade. I have no idea what a 5363 II is
worth, so go ahead and make an offer.
Stuff I'd be willing to trade for:
Apple & Mac clones
Interesting Apple stuff
PERQ/Alto/Star
Canon Cat/Swyft
Nutek One/Duet
NeXT cube
Apple II (plain II)
LEGO stuff (be it electronic or just bricks)
Note that "interesting Apple stuff" is an awfully broad category. Neat
Apple II cards are good.
Tom
Applefritter
www.applefritter.com
Unfortunately, there's a guy here in Chicago who took a bullet through his
skull last night: he was standing on his back porch while some people down
the alley were celebrating by firing off guns and fireworks. He's not dead
(yet), but definitely not in good shape.
-----Original Message-----
From: Mike Ford [mailto:mikeford@socal.rr.com]
Sent: Wednesday, July 04, 2001 7:38 PM
To: classiccmp(a)classiccmp.org
Subject: RE: 4th of July Hypocricy (was: OT Celebration)
<snip> Everybody
with a gun would fire off a few patriotic rounds too.
<snip>
I hate to put this on the list but I am unable to get Sridhar Ayengar (Vance
Dereksen) concerning some books he wanted. I need to hear from him in the
next few days or another buyer/recipient/etc will be found.
Peace...and write me...
Hi,
I was wondering if there are any Olivetti collectors around. Since I have
quite a few manuals in the well known Olivetti plastic boxes double I'd
like to swap for anything else.
Also I have like 6 crates full of parts that came out of Olivetti machines
that were made in the '70's.
Let me know if you are interested.
cya,
Stefan.
http://www.oldcomputercollection.com
On July 4, Carlos Murillo wrote:
> > Yes, fighting Darwin all the way. I HATE that. Protect and coddle
> >the stupid so they can annoy the hell out of the rest of us, and
> >dilute the GOOD genes in the process. ARGH!
>
> C'mon, Dave, I am sure that you realize that Darwin's idea of evolution
> has not been valid for our species for several millenia now...
I can hope, can't I?
-Dave McGuire
Hello,
I've got some time off from work, so I am trying to clean up and sort
through stuff. I know I already owe a few of you some boards.... I'll
be getting to them shortly.
Please respond directly to me at fernande(a)internet1.net ....this is
going to two groups!
Here's the new list:
-2400bps external Supra Modem
-Microchannel IDE adapter (Arco Electronics)
-STB video card, Tseng based, ISA MVP2X, dual head
-SMC Arcnet card, Microchannel
-Winchester drive controller.. RLL I think, 16-bit ISA
-MiniScribe RLL hard disks, Model 8425 ...2 of them
-Applesoft ][ Basic Programming Reference manual
-10 3M 8" floppy disks, I don't know if they are soft of hard sectored,
they are marked SS, SD, R ...they are in a plstic case and are new. I
bought them several years ago, as a novelty from a store going out of
business.
-uSpeed Fast 88, "Made in the USA and we are proud of it", I don't even
know what it is... it is on a piece of angled aluminum with a small PCB,
and has 4 chips along with some resistors and 4 clock crystal looking
dealies. Is connects to an XT usinf a 20 connductor ribbon cable that
goes to a dip socket on the MB.... wierd huh? If you what it is....
PLEASE tell me :-)
-Adaptec 2742W EISA Wide SCSI card WITHOUT the slot cover.... I don't
know why someone would remove it, but they did :-( I bought a generic
one, but it isn't in the right postion :-(
-2 Microchannel game port cards by Suncom, I bought them on Ebay, but
they don't seem to work with my Reply planer. They are odd, in that the
machine doen't ask for an ADF, and there is none provided.
-IBM Model 9577, Bermuda Planer, nice condition, both 3.5" and 5.25"
floppies, memory is probably around 24megs, has a 4xxmeg HD, has an XGA2
card
-the dumb TI PC (Texas Instruments Professional Computer) that I keep on
trying to give away, no keyboard or OS, and they are custom.
Well, thats all for now :-)
Chad Fernandez
Michigan, USA
I'm getting close to my wits end ...
I embarked on a project to catalog and archive all of the 5.25
inch floppies that I used on my PCjr. For archiving floppies
I decided to use savedskf and loaddskf (IBM utils), which run
under DOS and OS/2. I used a Pentium class machine with a
true 360KB diskette drive in the machine. I specified to
savedskf that I wanted raw, uncompressed binary images of
the diskettes. (The raw binary images are exactly size of the
diskettes (360KB), and are exactly the same as images created
using Linux's 'dd' command, so I know that they are really
raw binary images.)
All of the diskettes (150+) read fine, and are now sitting
as files on my hard drive. I decided to do some spot checking
of the diskette images, so I created new diskettes from the
images.
First problem: loaddskf will NOT write my 360KB images to
a real 360KB diskette drive. It complains about an unsupported
drive type. If I let savedskf write it's meta data and do
compression, then loaddskf will work. However, I want raw
binary images for compatibility with Linux 'dd. I can get
around it; there are lots of programs that can write the raw
diskette images. (fdwrite, fdimage, rawrite) However, I
am completely annoyed.
Second problem: I have two PCjrs for testing, and neither of
the two can read the diskettes created on my big machine. The
diskettes are being created using a real 360KB diskette drive,
yet they are barely readable in the two PCjrs. (They are
usually completely unreadable.)
I'm going to swap the 360KB diskette drive out of the Pentium
class machine and put another one there. Hopefully that drive
is out of alignment or the belts are loose, and that is why
the other two PCjrs can't read diskettes created on it.
Question 1: What the heck is up with loaddskf? Has anybody
run into problems with it when dealing with raw binary images?
It's supposed to work ... :-)
Question 2: Is there diagnostic software for determing the
alignment and RPMs of a diskette drive? I vagely remember
CopyIIPC telling me the rotational speed of the diskette
drive as it copied ... is there a diagnostic program that
can do this?
Question 3: What can I do to improve the chances of these
diskettes being interchangeable between systems? I've cleaned
the drive heads with a Q-Tip and isopropyl alcohol. I've also
cleaned the drive rails to ensure that the head can move
smoothly. Neither have helped.
Thanks,
Mike
A recent dumpster dive yielded a HP2748A papertape reader. Does anyone have
the interface spec's for this device handy ?
Left in the dumpster were : a Facit 4070 punch, a hp(8900?) diskdrive with
power supply.
The disk, vintage early to mid seventies, really should be saved but since I
do not have a fitting computer....
(Location Zurich , Switzerland )
Jos Dreesen
