Seems pacbell don't like my mail server (funny, just about everyone else
does). Anyway, the questions Jim asked are probably ones that other folks want
to know the answers to, so I'll post them here instead...
Jim Battle wrote:
>> It would be nice to have a 50 pin interface as well, for 8" disks.
Well the idea is that you have the 40-pin connector, and make up an adapter
cable for whatever drive you want to handle, then tell the software that (say)
output 1 needs to be high when track_number > 46, or whatever you need.
>> One problem is that a handful of the signals are non-standard. Ideally
these signals would have a wirewrap header where one could wire them to +5,
gnd, or perhaps to I/O pins on the FPGA under software control.
Again, 50-pin cable to adapter board, which plugs into the FDR and converts
the signals to suit the drive.
>> Is this intended as a read-only interface, or read/write?
*points at subject line*
Read/write.
>> For writing hard sectored disks, one has to initiate a given sector write
>from the relevant sector hole -- you can't write the whole track starting from
sector 0. This would imply some means of counting the sector holes, or at
least a way in the data stream of saying: wait until sector 0, data, data,
..., data, wait until next sector marker, data, data, ..., data, etc, stop.
Would you believe I've thought of that? :)
The writing side of things is controlled by a small microsequencer (think
'special purpose CPU'). The instructions it can handle are:
- Timer Load N - wait N clock periods, then write a flux transition
- STOP - stop processing further instructions and halt the machine
- Set Write Gate State - enable/disable the write amplifier
- Wait for hard-sector index mark
- Wait for N index pulses
So typically you'd do this:
WAIT_TRACKMARK ; sector 0 - wait for track start marker
WRITE_GATE_ON
TIMER_LOAD 123
TIMER_LOAD 42
...
WRITE_GATE_OFF
WAIT_INDEX ; sector 1
WRITE_GATE_ON
.. more write commands ..
WRITE_GATE_OFF
STOP
Thanks,
--
Phil. | (\_/) This is Bunny. Copy and paste Bunny
classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain
http://www.philpem.me.uk/ | (")_(") world domination.
Howdy, folks.
I just acquired an Acorn Risc PC 610 from a chap in the UK. The PSU
in it is labelled as a 220V-only affair. I understand there was an
autoranging PSU revision, but this does not appear to be one of them.
Does anybody have information on modifying this unit to work with
110V mains? Or a lead on a replacement PSU that has a switchable or
autoranging input voltage?
ok
bear
Time to unload the last of my duplicates. Here's a handy list:
http://spreadsheets.google.com/pub?key=pwMUKqpaWv1cq2nnM-h0wRA
$2/issue for anything 1984 and before. Anything I can get for the
later ones :) Bulk purchases encouraged!
All costs + shipping by Media Mail rate (or faster if you prefer) from
60074. Of course local pickup is fine, too.
Help me clear out some space and save these from the recycler!
--
jht
I've got a QIC-150 tape (3M DC6150) with some backup on it, probably
>from RSX11. Table of contents (paper one) reads:
RSXCTDQ0
RSXCTDQ1
RSXSMDM0
CTDQKIT2
ALISAKIT2
ALISASM
I have no idea what it is, I have no experience with RSX11 and I need
that tape (physical medium) for other purpose. What's the best way
to preserve the contents, preferably using FreeBSD? Is repeated
'dd if=/dev/nsa0 of=output_file1', 'dd if=/dev/nsa0 of=output_file2'
until end-of-media enough?
Drive is Wangtek 5150ES.
--
If you cut off my head, what would I say? Me and my head, or me and my body?
Hi list,
The above need to find a new home within about a week or they get recycled.
Free, but you pay shipping. Will ship to anywhere in the world.
Please reply directly to me as list traffic is still a bit funny for me atm.
Thanks,
Ed.
At 10:43 AM 2/12/2008, you wrote:
>http://www.frappr.com/?a=constellation_map&mapid=137440346730
>
>How's that?
Easy enough! Strange that Frappr's address-to-location isn't as accurate
as Google Maps, though. It placed me in the wrong place twice and it's
still not right.
- John
A fellow I knew years ago just phoned me for some help rejuvenating some old
analog instrumentation chart recorders - he collects such stuff apparently. He
works as an operator at one of the oil depots in the region (downsized from a
refinery a couple of years ago) and is preparing displays for their 50th anniversary.
After the instrumentation stuff was discussed, and knowing where he worked, I
started telling him the story of the scrapped Foxboro processor at the old
refinery closer to me (I told that story on the list a couple of years ago),
kind of angling to find out what might be the state of the old computer control
system where he worked.
He said "Do you know 'Digital' computers? When the refinery was decomm'ed we
threw out an 11/70, it was spread across like 4 racks. Boy, I woulda called ya
if I knew you were into stuff like that, it was sad to see it scrapped."
ho hum.
(.. and just checked the 11/40 on ebay to see it hit over $1000.)
Hi
I made good progress today. I got the programmer working again.
I'm now doing 2716s on the PB-10 again.
I blew some more test code and also figured what the problem was
with the controller.
Previously, I'd gotten the frequencies change in the crystal and
PLL circuits. I got to the point that it appeared to be reading the
disk into the USART chip but not getting data into the dual ported
RAM. It was still erroring on the header. I wrote code to ignore
the header and tried that. It still seemed to be missing the header
data.
This is when the programmer decided to cause problems.
While waiting to get parts I realized what the problem
was with the controller.
I was running everything from the memory window in the
Poly88s monitor. Every time it updates a single byte,
it rereads a large block of memory to put into the display.
I was pointing to the RAM that was double ported and
this stole cycles from the controllers time. This caused
missed bytes from the USART.
I wrote some simple code in another area of memory and
used that to initiate the read command. It was then reading
the header and data without missing any of the header or
data.
I expect I'll soon make greater progress.
I need to delay some before reading the double ported RAM
or the controller will miss the first few bytes.
I need to write my serial transfer and finish the code for
reading the sectors.
Dwight
_________________________________________________________________
Shed those extra pounds with MSN and The Biggest Loser!
http://biggestloser.msn.com/
Urgh, apologies for any font issues. Had to copy and paste my reply
as Yahoo failed to deliver it to the classiccmp servers twice! Not sure if
bounced or not, but here's the error message:
Remote host said: 550 5.7.1 time travel between hops [BODY]
Classiccmp.org rejected it once, giving this error message:<cctalk at classiccmp.org>:
Remote host said: 553 5.3.0 Spam blocked see:
http://spamcop.net/bl.shtml?76.13.13.74 [MAIL_FROM]
This last (and 4th) attempt at replying, is being done from Outlook Express onmy laptop as opposed to Yahoo's webmail.
My reply:
Would it work with a Famicom (Japanese SNES) mouse? Since it was
compatible with MSX games it might work, but probably doesn't fall
into the
"easily obtainable" category :(
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
Syd Bolton <sbolton at bfree.on.ca> wrote: I see the pinouts online but
haven't checked to
> see if it's compatible with a standard Atari type joystick.
>Sure it is!
> Interesting how MSX devices are unknown here...They are so popular in
>Brazil!
That's just how it goes! OK second part of my question then: what about
the
mouse? What other more easily obtainable mouse would work on the MSX
machine? Commodore made mice with 9-pin connectors for the C64 but I
doubt
it would work or the Amiga one .... and of course, the "serial" mouse
from a
PC I would expect won't work as well.
Or....I guess more easily does anyone out there have an MSX compatible
mouse
they'd like to sell me for the museum? Thanks
This is a test email to see if it makes it through to the list. The last 3 attempts at replying to a message were bounced (twice by Yahoo and once by Classiccmp servers).
If this makes it through please ignore.
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk