"Bob Armstrong" <bob at jfcl.com> skrev:
>
>> Sridhar Ayengar (ploopster at gmail.com) wrote:
>
>> Or if you're willing to write an MSCP layer into your controller firmware.
>
> I actually think this is the "right" way to solve the problem in the case
> of the PDP-11 and VAX, but then controller is no longer a simple device.
I'd say it would definitely be the right way.
What people seem to forget (or ignore) is that unless you decide to emulate an
existing DEC device, you not only need to write a device driver for the OS,
which sure is some work, but doable.
But you also need to write some bootstrap code, which needs to be placed in a
rom. That will quickly get a bit more ugly...
There is a big difference to a PDP-8, which this has been compared to up until
now. The PDP-8 is really simple in design, and so is booting one, usually.
A PDP-11 is way more complex to boot. Not only do you need the initial boot
code, in the boot ROM. You then also need the bootstrap for the OS, which
resides on disk. I don't know about RT-11, but for RSX, this is a separate piece
of a driver which in no way is related to the device driver that you use once
the system is booted. And this piece is tightly integrated with the OS and is
embedded deep inside stuff.
So, unless you want a disk that you can't boot from, you have a big chunk of
work to get it working.
So doing an emulation of an existing device makes much more sense.
And of all the existing devices, MSCP is by far the best choice when picking
something to map to modern hardware.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On 2 Mar, 2008, at 14:41, cctalk-request at classiccmp.org wrote:
> Message: 12
> Date: Sat, 01 Mar 2008 23:19:43 -0800
> From: "Chuck Guzis" <cclist at sydex.com>
>
> Well, if I were debugging hardware, I'll take a logic analyzer and a
> scope, thank you. I'm not sure how broad the range of hardware
> faults is that a bunch of blinking LEDs will indicate.
I find that about half of all CPU faults on my 1301 can be found from
the front panel, but then it is a remarkable front panel. I can slow
the clock rate down to three pulses per second and watch the
individual steps in each instruction, watch data shifting through the
registers, watch the carry bits in the mill, watch the instructions
shifting through the registers etc. I can even run it at one pulse
per button press and change the data in the registers and create
parity errors and write them to core and read them back and watch the
parity checker do its stuff.
Not so useful with peripherals though, I find a storage scope is
invaluable for them, the more traces the better, so I suppose a logic
analyser would be useful, but does one exists for MINUS 6.3 volt
logic? I always presumed they were only invented after silicon
replaced germanium and so only work with positive logic voltages.
Probably out of my price range anyway for home use.
> Date: Mon, 03 Mar 2008 20:50:43 -0800
> From: Josh Dersch <derschjo at msu.edu>
> Anyone got one they're looking to get rid of/sell/trade? My venerable
> IIfx's RAM has gone bad and rather than pay stupid prices for 64-pin
> simms (which are just going to be harder and harder to find) I'd like to
> get something that takes standard stuff. And while I'm doing that I
> might as well get something large and heavy :).
>
> Thanks!
> Josh
30 pin SIMMs in the 16 MB capacity aren't exactly falling off of trees
these days, either. :-) Of course, if you're happy with the smaller
capacities, then they almost are. And the Q9xx does have 16 SIMM
sockets...
I've been making 16MB SIMMs for the IIfx, so one could argue that they are
not getting more rare, unless they are being lost by the population faster
than I am making them. However, the prices may be stupid. I mainly sold
them on Ebay and the prices for a set of four ranged from under $30 to
over $250 with somewhere in the $120 - $150 range being typical.
Right now I have components for several more sets, but have been
overwhelmed with other priorities and have not assembled any more sets.
Jeff Walther
Re:
> I a have a lot of mag tape/cartridge tape that I would like to analyze.
I may have misinterpreted your post.
Are you trying to analyze the data currently on the tapes,
or analyze the quality of the tape (trashing any data currently
on the tape)?
For the latter, I've got one (TAPECHK) for the HP 3000 which I'd be happy
to send you ... but it's not readily portable to other platforms,
unfortunately. (I originally called it TapeAnal, for "tape analyzer",
until I re-read that name one day :)
Stan
--
Stan Sieler
sieler at allegro.comwww.allegro.com/sieler/wanted/index.html
Re:
> I a have a lot of mag tape/cartridge tape that I would like to analyze.
>
> I there a program that would write the whole tape then read it back,
> logging the retries and the errors.
Eric Smith has "tapecopy", which copies tapes to disk in a simple format.
I think a number of people use that ... but I don't recall it logging
error information.
I've got my own TAPEDISK, which does something similar. My format
allows me to record which records had errors or retries, where setmarks
are (for DDS), and optionally internally compress the data (using open
source zlib). If anyone's interested in my format, I'd be glad to
open it up. At present, I use it mostly to read/save tapes on HP 3000s
(where tape blocks can exceed 64 KB).
Stan
--
Stan Sieler
sieler at allegro.comwww.allegro.com/sieler/wanted/index.html
When I was at the VCF in Mountain View this past fall, someone in the
concessions area had an HP 87 computer/calculator for sale. Does
anyone remember who that was? I find I'm getting interested in the HP
8x series.
Thanks!
David Betz
At 22:32 -0600 3/3/08, "Merch" wrote:
>Now you've given me one heckuva reason to spark up the latest Vcc (that's
>not +5v, it's the latest virtual CoCo[1] from David Keil) & try it on OS-9.
>
>[1] http://vcc6809.bravehost.com/
Dang it! Somebody needs to donate a Mac or linux box to David Keil,
because I really like CoCo3's but I really don't ...
<flame-bait deleted>
--
- Mark, 210-379-4635
-----------------------------------------------------------------------
Large Asteroids headed toward planets
inhabited by beings that don't have
technology adequate to stop them:
Think of it as Evolution in Fast-Forward.
Anyone got one they're looking to get rid of/sell/trade? My venerable
IIfx's RAM has gone bad and rather than pay stupid prices for 64-pin
simms (which are just going to be harder and harder to find) I'd like to
get something that takes standard stuff. And while I'm doing that I
might as well get something large and heavy :).
Thanks!
Josh
Since Pat F. is holding VCF Midwest early this year, we decided to balance
things out by holding VCF East later this year. So, VCF East 5.0 will be
the weekend of September 13-14. Same place as the last two years -- InfoAge
Science Center in Wall, New Jersey. This year there's no special theme, but
there will be a special event -- the beta opening of our computer museum.
We're going from the current 12x10-foot "preview" room into 800 sq. ft.!
Details to be announced later.
- Evan
