Tim Shoppa wrote:
>Some real-time operating systems can be pressed into service as
>general-purpose multi-user OS's. For example, RSX-11M. Others
>make quite nice single-user development platforms - for example RT-11.
>
Did something fall into place here for me?
Does the "RT" in RT-11 happen to stand for Real Time?
Hans Olminkhof
See my one comment embedded below, plz.
Dick
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, April 18, 1999 2:08 PM
Subject: Re: z80 timing... 6502 timing
>>
>> I want to distance myself from the majority of this nonsense. Building a
>> simple computer with a processor, a ROM, a full compliment of RAM, and a
>> serial console interface is a 10-minute design and a 90-minute
fabrication
>
>Less than that, actually. There's nothing to 'design' IMHO - just stick
>the chips on a piece of wire-wrap board and wire-wrap the address and
>data buses. While you're doing that, design the address decoder with the
>other half of your brain.
>
>I built a 6809 SBC years ago, and the chip count was pretty minimal.
>IIRC:
>6809 CPU + 4MHz crystal as the clock
>2 off 6264 RAMs (16K RAM total)
>2764 EPROM and space for a second one
>6551 + MAX232 serial port
>9914+75160+75162 GPIB port (that was in the spec, obviously not needed
>for a general-purpose machine).
>2 off 74LS138 address decoders (one to divide the memory map up into 8K
>blocks, the other to subdivide one block for the I/O chips). These days
>I'd use a GAL.
>A couple of TTL latches and buffers for I/O ports (cofig switches, status
>LEDs, etc).
>
>That was it. Obviously a 6502 could be used with much the same hardware.
>A Z80 wouldn't be any worse either.
Rockwell made a 65C102 available in the same speed grades as the 65C02.
This used a quadrature clock just like the 6809 and worked pretty much like
it as well, at least insofar as the timing circuit was concerned.
>> Now I can't imagine why a graphics display, or anything so inane as that
>> could creep into the consciousness of an otherwise perfectly sane person
>> wishing to deal with one of life's fundamental mysteries, i.e. "which is
>> really faster, the XXXX or the YYYY?"
>
>Oh, Sam was suggesting all sorts of complex features and I was pointing
>out that most of them weren't that hard to add if you really wanted them.
>You don't want them for this challenge IMHO.
>
>-tony
>
That's what y ou have to do when you start with nothing. It's not a new
concept.
Dick
-----Original Message-----
From: Mike Ford <mikeford(a)netwiz.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, April 18, 1999 2:10 PM
Subject: Re: z80 timing... 6502 timing
>>Sure! Let's have a driving contest to see who can drive the fastest, but
>>first we all have to build our own cars. THAT MAKES AN AMAZING AMOUNT OF
>>SENSE!
>
>Shsssh! We're building a race track first.
>
>
please see the embedded comments below.
Dick
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, April 18, 1999 2:05 PM
Subject: Re: z80 timing... 6502 timing
>>
>> If one were going to put an FDC in place, the easiest probably would be
the
>> WD3765, since it has built in cable-drivers and receivers as well as
>
>Sure. Or one of the similar, but incompatibly pinned-out UMC disk
>controller chips.
>
>Heck, it wouldn't be hard to add one of the multi-I/O chips from a PC I/O
>card and have FDC, 2 serial ports and a printer port. Most of them only
>need an 8-bit data bus for those functions.
>
>> clock/data processing hardware. You connect it directly to the cable, as
I
>> recall. It otherwise behaves as a uPD765 (i8272).
>
>Absolutely. The point I was making (not very clearly) is that WD FDC
>chips are getting hard to find, but there's no reason not to use an 8272
>(or one of the later chips based on this, but with more things integrated
>into the device).
>
>But if you insist on 'classic' hardware (meaning all the chips you use
>were in production at least 10 years ago), you probably won't be allowed
>to use some of these more integrated devices.
That's exactly the reason I'd prefer to use the WD1002 boards I have around.
They handle both the FDC and HDC functions with a minimum of extraneous
hardware and would, at least in the case of the Z-80 lead to a productive
OS. That's not as likely in the case of the 6502, since there wasn't much
of use around for it. Nonetheless, a nonvolatile storage medium of some
sort would be convenient, and if I make the board in question home to both
processors there'll be no doubt about whether one or the other has more or
better resources. I got these boards in 1982. When they were brand new
products and, in the case of the 1002's, before they were released
commecially.
>-tony
At 09:18 PM 4/18/99 -0700, you wrote:
>
>In case anyone's wondering what everything is in the pictures Mr. Willing
>took at Paxton's auction, I've identified as many things as I can so that
>if anyone ever spots one of these in their travels and wonders if its
>worth their while to pick up, they'll at least have an idea what they're
>looking at.
<snippage>
> P023.JPG 17-Apr-1999 22:02 64k
>
>Damn it! Damn it all to hell! That's the HP 9000/520 Unix workstation
>I've been lusting for!! Frank McConnell has the only one I've ever seen.
Well then, you're gonna hate me! It followed me home! (or at least, will
as soon as I get back to pick it up!)
> P024.JPG 17-Apr-1999 22:02 73k
>
>Tektronix 4001 (or 4002?) storage scope.
Well... I thot it was a 4002 as well... It is a 4006-1. It followed me
home too!
> P044.JPG 17-Apr-1999 22:03 79k
>
>Is this the HP1000F? I thought you said it was an empty chassis.
No, I said I got the CPUs only (as opposed to a complete system). P044.JPG
is the rear of the unit, P045.JPG is the front. B^}
-jim
---
jimw(a)computergarage.org
The Computer Garage - http://www.computergarage.org
Computer Garage Fax - (503) 646-0174
At the risk of boring the Regulars (please forgive) I would like
to take some bandwidth to extend an invitation to any Classiccmpers
who will be in the Southern California area this coming weekend, the
24th of April, 99.....
The TRW Ham Radio and Electronics swapmeet will be held at the TRW
facility in El Segundo, Ca, from 7:30am until 11:30am local time.
>I need some help identifing some of the boards that I pulled out of Paxtons
>yesterday:
>
> M7904 - Not listed in the Field Guide
> Hex-Height
> 40-pin ribbon cable sticking out the side
This is one of the five boards (M7900-M7904) in the RK06 system
unit. This particular board contains the drivers for the actual
drive interface.
> NDLV-11
> netcom products, inc.
> copyright jan. 1979
--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote:
> > > Which pins are used on the 50 pin connector? Could it be pinned out as a
> > > SCSI port. Or is it possibly some custom host interface?
> >
> > It could be a custom host interface. Among other anomalies, I don't see
> > any terminating resistors.
>
> Doesn't sound like SCSI/SASI, then...
>
> > Can you scan that data sheet or send me a photocopy? I'd pay for
> > copying/mailing.
>
> Sure, but from what others have said, I don't think it'll be a lot of use
> to you.
Well... does anyone need this? I happen to have the enclosure that goes
with it too. It says "Davong" on the outside and has a one-piece lid with
broad, rounded corners, not boxy.
> > > 20MHz/4 = 5MHz = standard ST506 data rate.
> >
> > Right. It's the right rate for an 8" disk.
>
> Is it? I thought the 8" winchesters had a 4.34MHz data rate.
To repeat myself, that's a typo. I meant to say "...not the right rate...".
Mea culpa.
If anyone can put this to use, let me know. I can't imagine anything I'll
own in the near future that needs it.
-ethan
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
On Apr 18, 11:58, Sellam Ismail wrote:
> Can you scan this card and the Xebec interfaces you have and post a
> picture of them somewhere? I then might be able to tell you if you've
got
> a winning combination.
Sadly, that's one of the projects that's "less than complete" at the
moment.
> Ok, I just took stock of the hardware in my next room. I have a First
> Class Peripherals Sider ][ hard drive (actually two) and for the first
> time ever noticed that they have a Xebec label on the bottom, which I
> guess means these are actually Xebec hard drives and First Class was the
> name they sold hard drives under? Whatever.
I didn't know Xebec made drives, but it's perfectly possible. They used to
describe themselves as the "Zero Defect" company, so that would fit.
> Ok, so then I opened one up and noticed a Xebec PCB that is the same size
> as a 5.25" drive, that contains among many other things a Z80, an 8502
and
> a ROM with a Xebec label. The connector is 50 pins.
Sounds just like mine.
> I then opened the Apple //e hood and the Xebec controller card also has
50
> pins.
Ah. Well, I didn't really expect you'd have a setup that was quite the
same. Thanks very much for taking the trouble to check, though.
> So I'm not familiar with the card you have at only 26 pins.
>
> > Was there a standard pinout on Apple SCSI/SASI boards? Perhaps it's
the
> > same as the Mac 25-pin SCSI?
>
> If you consider Xebec to be the standard then yes. I've never seen a
hard
> drive controller made by any company other than Xebec.
Hmm... I've seen lots, notably Adaptec and Xylogics... but perhaps you mean
in an Apple environment -- in which case the only other name that comes to
mind is Corvus, and I've no idea what they used. Not SCSI, I think.
Still, I've got a few ideas, so tomorrow I'll go and dig out the Mac
manuals and look at their 25-pin interface, and check some of the traces on
the Apple board to see if there's a plausible match.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I need some help identifing some of the boards that I pulled out of Paxtons
yesterday:
M7904 - Not listed in the Field Guide
Hex-Height
40-pin ribbon cable sticking out the side
NDLV-11
netcom products, inc.
copyright jan. 1979
MSI-11 (c)1978
Andromeda Systems Inc
faded sticker on handle says 'MUX1' and 'MUX3' the rest is to
faded to read
A two board set from Plessey Peripheral Systems connected via a 50-pin
ribbon cable. The top board (P/N 703580) has 8 LEDs and a 10-pin
connector. The bottom board (P/N 703570) has 4 26-pin connectors and a
roughly 66-pin connector (not sure its exact size). The only thing I can
think of is some kind of drive controller.
Zane
| Zane H. Healy | UNIX Systems Adminstrator |
| healyzh(a)aracnet.com (primary) | Linux Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| and Zane's Computer Museum. |
| http://www.dragonfire.net/~healyzh/ |
