Hi folks,
Norm Aleks and I have some big iron bits to give away, caveat is they
have to be picked up on or before Wednesday July 19. Location is
Oakland, CA. You'll need a truck w/liftgate (preferably), or we can
arrange for our storage facility's forklift to help move if you
can meet us on the morning of the 19th. Items are:
3 ea. IBM 3380-B4 DASD slave (must hook to -A4 to be used)
1 ea. IBM 3880-2 DASD controller
1 ea. IBM 3880-3 DASD controller
1 ea. IBM 3380-4 DASD controller
1 ea. IBM 3420-3 9-track tape drive, low density
2 ea. IBM 3420-8 9-track tape, high density
These are BIG and HEAVY and would look VERY COOL in your basement or
office. Or bedroom, if you're into that sort of thing. Some of the
3880 boxes are in the less common red color scheme. The DASD and
controllers can actually be put to practical use, by scrapping the
electronics and installing plywood shelves, wherein they become once
again useful storage devices. [Disclosures: Some of the cabinets are
in less than pristine physical condition. One of the 3420s is missing
its door].
Contact me off-list if interested. What's not picked up will go to
BDI for auction & most likely scrapping.
Regards
Brian
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
_| _| _| Brian Knittel
_| _| _| Quarterbyte Systems, Inc.
_| _| _| Tel: 1-510-559-7930
_| _| _| Fax: 1-510-525-6889
_| _| _| Email: brian at quarterbyte.com
_| _| _| http://www.quarterbyte.com
>
>Subject: Re: OMTI parallel port interface hack
> From: ard at p850ug1.demon.co.uk (Tony Duell)
> Date: Sun, 09 Jul 2006 21:20:12 +0100 (BST)
> To: cctalk at classiccmp.org
>
>>
>> The typical application of most 8255's, I'm going to guess is that they're
>> initialized at the start of an application or when the computer is booted
>> and the mode is never fiddled with thereafter.
>
>As I mentioned in my reply to Allison, it's worse than that.
>
>On reset, the line is an input, so a TTL input connected to it will treat
>it as high (it would be good practice to add a pull-up resistor, sure)
>
>On writing to the mode register, that TTL input will be forced low
>
>Then you might make it high again.
>
>Your external circuit has to be happy with this (it can't assume the line
>will stay high as the chip is initialised). The other parallel chips
>(e.g. 68721, 6522) don't have this problem, with those, you can write to
>the output port register and make outputs effectively 1 _before_ writing
>to the direction register. Then if you have an exetrnal pull-up, or
>assume a TTL input floats high (naughty!), you will not get a momentary
>low glitch on the line.
The 6522 is sometimes nice but hard to find. and for many the 68721 is
even harder to find.
As someone said, 8255s, the roads paved with them. Also how often do
you have to turn a port around? Apps where I needed that I found that
there were other approaches that worked better.
>>
>> Does the 8251 USART also have some sort of strange initialization problem?
>> It's been a long time since I've used one, but I seem to recall a gotcha.
>
>IIRC, it's impossible in gnneral to force it into a known state. If
>you're setting it up for synchronous operation and forget how many of the
>initialisation bytes you've sent it, there's no software way to force it
>into a known state from where you can start the initialisation again (a
>hardware reset will do it, of course).
Most sync mode chip setups are a PITA!
If you forget how many init bytes you sent, your software is broken
or Alzhimers. Also issuing a reset command after a data port read
works. The 8251/9551/2651 and related varients are all annoying
about that. In general I dislike chips that need to be pumped with a
string of bytes to one address for init. However most behave and it's
not that hard to sort out. However since most of the S100 crates I have
and many systems I've built 8251s are familiar and used as I still
have tubes of them. However it's not my first choice for Sync ops
though for async its fine.
Allison
>
>-tony
Speaking of Superbrains...
I saved 2 superbrains from extinction many years ago, and never had a
chance to diddle with them; but I must say the zoo where they're caged is
under disrepair. They powered up & asked for a boot disk last time I tried,
but that was prolly 5 years ago - they've been kept in an unheated garage
since. They've been out of the rain & all, but it's a dusty, dirty garage,
so they'll need some cleaning, TLC & whatnot...
IIRC (but don't trust my memory) one's a SBII, the other might be an SB QB,
each has at least one floppy, but I don't remember if either has 2. Other
than that, I never really knew much about 'em.
I'll be at VCF-MW 2.0, so delivery could be free to Indiana this weekend.
Thanks,
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger | "Profile, don't speculate."
SysAdmin, Iceberg Computers | Daniel J. Bernstein
zmerch at 30below.com |
I've been contacted by someone who has a whole pile of old teletype paper,
tape and related stuff that he needs to clear out.
"6 boxes (12ea) 8 7/16 white single roll; 50 black & 28 buff/canary rolls
teletype tape; 44 ink ribbon bobbins (empty) ; 2 boxes continuous flatfold
tabulating machine paper (single); 2 boxes tabulating paper 8 1/2 x11 (two
part) 2 boxes teletype ribbon (purple) 1 box teletype ribbon (black 1/2")
and a couple strays, and 8-9 boxes other ribbon (see photo)"
I'd like some of this stuff but there's no way I can ship or store all of
it. Would anyone else be interested in some?
As far as I can tell this is all NOS stuff. You can see some pictures at
http://www.vintage-computer.com/vcforum/showthread.php?p=23825#post23825
Please let me know if you're interested.
Erik Klein
www.vintage-computer.comwww.vintage-computer.com/vcforum
The Vintage Computer Forum
As I mentioned earlier, here is the rest of the list of things I will
have available at VCF/Midwest. Want one of these? Drop me an email
ahead of time and I'll hold an item for you, otherwise locate me at VCF.
Some of these are missing RAM or a hard drive, but should be runnable
with the missing bits installed (no toasty motherboards or anything
like that).
2x SPARCstation 5
1x SPARCstation 20
2x Javastation
1x HP 9000 715/64
1x HP 9000 300/345
1x HP 9000 C110
2x SGI Indigo2 (one XZ, one High Impact)
1x Macintosh IIci
1x Macintosh G3 (beige model)
3x NCD MCX
1x NCD MCX-L
1x Cisco IGS
2x ISA GPIB boards (one HP, one NI)
1x IdeaComm 5250/Remote
1x 3Com Wireless Bridge
1x Webpal
These are free for the taking, but if you've got some spare Alpha PWS
RAM, quiet 68-pin SCSI hard drives, or interesting RS/6000 gear, I would
be more than happy to help you "dispose" of it ;)
-Ryan
Seems like I am a couple 1.44 MB Mac 68k superdrives short for my machines (the old auto inject used in Mac II's and Quadras, not the black door manual inject variety), anybody have a couple they don't need? I recall somebody here had a stack a while back they were offering but I can't find the email in my archive.
Thanks,
TZ
> Anyone like to add their two cents?
Find an ISA board with an NCR 5380 scsi chip on it.
I'll run over to Weird Stuff tomorrow to look.
5380's are VERY simple minded, and will work with little programming on
older controllers like the Xebec 1403 in the picture.
