I'm working on supporting GPIB tablet support for PERQemu (right now it
only supports the 3-button Kriz tablet). Anyone have documentation for
the protocol used by the GPIB variant of the Summagraphics Bit Pad One?
I've found documentation covering the Bit Pad Two
(http://www.calcomp.com/files/Bit%20Pad%202%20Tech%20Ref.pdf) , which
appears to be RS-232 only. I'm sure the protocols are similar, anyone
know for sure?
On 11/25/09, allison <ajp166 at verizon.net> wrote:
>> I should probably make a post there about my new-to-me VT78. It
>> checks out so far, but I don't have a copy of OS/78 to do anything
>> "fun" on it yet. I was hoping someone here would respond to my query
>> about what's out there for the MR78
> The MR78 was only used for the booter.
Right. It's just a bunch of ROMs and clock chips pretending to be a
PR8E-like papertape reader.
> I believe there were at least two booters, RX01, RX02.
I've found reference for those as well as a mention of a diagnostic
ROM set. I would like to be able to put together a box with 4x or 8x
the normal ROM, use modern ROMs and burn all known booters rather than
hack on my one-and-only MR78. Fortunately, it hangs off of a DB25, so
it should be trivial to redesign and build in the same space.
> OS/78 you need to find it on the net, then copy to RX01
> formatted 8" floppy.
I've seen OS/278 from the DECUS collection. I must not be looking
into the right places for OS/78. Writing the RX01 floppy is no big
deal - with what I have sitting around the house, the shortest path is
probably to throw an RXV11 or RXV12 into a Qbus box and use vtserver
to move the disk image. The second shortest path would be to get
around to assembling a 34-to-50-pin cable and using an old PC to write
the image. Fortunately, I have multiple 8" drives and several boxes
of still-in-the-shrinkwrap 8" disks, most (but not all) already
formatted in IBM 3740 format.
Machine is in Croydon, Surrey, England, FWIW.
From: queenofcroydon <queenofcroydon at yahoo.co.uk>
Date: Fri, Nov 27, 2009 at 1:19 PM
Subject: [Croydon-Freecycle] Offer: OLD Apple Mac, CR0
To: Croydon-Freecycle at yahoogroups.com
I have a Macintosh Performa 600 Series with CD-ROM
Complete with Monitor, Keyboard, Mouse and external zip drive.
I found a picture on "PC-Museum"
I know that this machine is from the technical perspective kind of if medieval.
But maybe there is a MAC-fan out there somewhere, who likes this one.
It is fully functional, comes with most of the manuals.
Please let me know if you would like to have it - will just go as a bundle!
Liam Proven ? Profile: http://www.linkedin.com/in/liamproven
Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com
Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419
AOL/AIM/iChat/Yahoo/Skype: liamproven ? LiveJournal/Twitter: lproven
MSN: lproven at hotmail.com ? ICQ: 73187508
Several months ago, someone was looking for an image of the 23-018E2
character generator ROM for a VT100. A generous reader has given me an
image, which I've uploaded to my website at
Better late than never, I hope!
Pete Peter Turnbull
University of York
On Tue, Nov 24, 2009 at 8:15 AM, Zane H. Healy <healyzh at aracnet.com> wrote:
> IBM had one or two *INTERESTING* PC desktop designs I've seen that would be
> nearing 10 years old. A few others have as well, but I'm honestly not sure
> anything that was built to run MS Windows will really ever be on-topic, that
> would include modern Macs.
So it sounds to me like the rule is, "anything that doesn't run windows,
either because of insufficient power or design."
Although some of the 486 or greater single board computer/passive backplane
thingies could easily run windows. So maybe we need an exemption for
anything that has a design that isn't a classic PC.
And if we exclude modern macs, does that exclusion include the Cube and Mac
Mini? I want both of those machines eventually. What about that goofy mac
that looks like a half-dome with an LCD monitor sticking out? That's
certainly interesting. Was that one intel or did it slip out before the
And which version of windows was it that ran on the dec alpha?
> Message: 26
> Date: Wed, 25 Nov 2009 21:18:13 +0000 (GMT)
> From: ard at p850ug1.demon.co.uk (Tony Duell)
> Subject: Re: Cleaning packs
> To: cctalk at classiccmp.org
> Message-ID: <m1NDPFl-000J3yC at p850ug1>
> Content-Type: text/plain
> > On Nov 24, 2009, at 1:08 PM, geoffrey oltmans wrote:
> > > Dumb question (perhaps), but do the relative positions of the disk
> > > platters in the pack matter on these systems? I suppose it might for
> > > interleaving purposes for data already recorded.
> > I would suspect yes but never having cleaned multi-platter packs, I'd
> > only do that on packs that I don't care about the data (ie I'm going
> > to format the pack as soon as it's "clean"). If I care about the data
> > that *might* be on them I probably wouldn't disassemble (ie de-stack)
> > the pack.
> I would be very careful about dismantling the pack for another reason.
> Often there is no automatic centring of the platters. If you seprate
> them, you will have to centre them up. On the (crashed) 5-platter pack I
> dismantled about 25 years ago (for interest), there were holes throuch
> the top and bottom hparts of the hub through which you put long rods to
> keep the platters and spacers _approximately_ cententerd. But then, I
> think, you have to put the hu on the drive spindle (or a similar spindle
> in a test rig) nd use a dial gauge to position the platters so there's
> no run-out when you rotate the stack by hand. Given that moving one
> platter is likely to slightly move all the others, this is a long and
> tedious job.
I would not clean any pack that had a lubricated disk surface. The good
news is I am pretty sure that lubrication was introduced with the IBM 3340
(Winchester) so the 2315, 2316, 3336, 3336-11, SMD and their DEC equivalents
(RP0x, etc) were not lubricated. I don't know anything about the later
uniquely DEC packs but I expect they used high load heads and were not
As I recall we cleaned non-lubricated disk packs with a tongue depressor, a
non shedding wipe (Kim Wipe) and isopropyl alcohol (medical grade). You
want to make sure there is no residue!
If you don't care about the data you can disassemble and reassemble disk
packs that do not use a track following servo systems, that is 2316 and
2x2316 types. You do not have to center them up!
If you are real careful you can disassemble and reassemble a servo type disk
pack so long as you are very, very careful not to move (or replace) the disk
containing the servo pattern! This applies to the 3330 and SMD type of disk
packs. A while ago, I was surprised to find out that several "recovery"
houses were doing this routinely and claiming to recover data on the
original disks still in the pack!. If you do move the servo disk, as
witnessed by repeatable runout in the servo system, I am told that some
skilled folks can actually center them up by careful instrumentation,
measurement and gentle tapping of the servo disk in a not fully tightened