> Anyway, I'd really like to know more about your experience if
> you can remember any details.
Well, it was a looong time ago. It was a short card with two RCA (phono)
jacks as I recall. I had it installed in a Hyundai (yes, same as the car
maker) 386/DX20. I seem to recall I'd get somewhere in the middle of the
tape during a restore and it would fail. I don't remember the nature of
the failure. I also seem to recall it corrupting restored files on my
disk.
There is a small chance that I still have it hiding in a box somewhere.
It would be in the corner of the basement that I'm working my way toward
cleaning. Perhaps I'll find it this spring. I'm not known for throwing
stuff out ;-)
Over the years I've learned to never trust tape of any kind. I expect a
backup system to be completely trustworthy and until recently I haven't
found any I'd trust that much. Maybe I shouldn't now, either - but I
haven't been burned lately.
I know it's not a crucial new announcement or anything, just an
update...
Just fyi, I've reorged my Nova 4 website (http://wps.com/NOVA4/) a
bit. Took some of photos of internals, such as the disk drive
(when I re-cleaned the heads after 20 hours of operation --
utterly spotless, whew!) last week.
Changed are mainly organization, plus added photos, and a tiny bit
of software, including classic (sic) MORE.
I've been an idiot about this Kermit program, I'm workign on it
now.
Ethan Dicks <ethan.dicks at gmail.com> wrote:
> in the case of Qbus and Unibus boards, since the
> fingers are gold, it has to be due to oxide build up on the backplane
> pins.
Aren't the backplane contacts also gold-plated?
MS
>From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk>
>
>On Mon, 2005-03-14 at 11:55 -0800, Dwight K. Elvey wrote:
>> >From: "woodelf" <bfranchuk at jetnet.ab.ca>
>> >Look what you are doing is building a generic floppy disk controler.
>> >The only high speed device what you use to sync the data/clock pulses
>> >to the system cpu clock. The rest is software. I'd sooner use a CPLD
>> >designed for generic bit sampling but a PIC would also work with
>> >a digital data/clock seperator. Now would getting the people who do
>> >cat-weasel create a USB version be a better goal?
>> >Ben alias woodelf
>> >PS. What about hard-sectored floppy disks, that too may need reading
>> >too?
>>
>> Hi
>> I think you are missing what I am saying. The SPI is just
>> a shift register that takes an external clock. It can be programmed
>> to automatically DMA transfer into memory. It is the perfect zero
>> additional logic circuit to use. You don't need to build a
>> data/clock separator or anything. Just sample the data.
>> One could even make the output SPI provide write data. These
>> chips are designed to load their programs from a single
>> flash or EPROM so the entire hardware requirement is almost
>> nothing.
>> I see others on comp.os.cpm talk about using a 50MHz variant
>> of a Z80. I think most miss the point. These DSP's are 30 MIPS+
>> not just 50 MHz clocks. They have enormous capabilities in
>> a relatively small package. It was like they were designed for
>> this project. You don't need to create a CPLD since the hardware
>> part is already done for you.
>
>What about cost? (irrespective of how the device physically connects to
>the host machine)
>
>I forsee four goals to make it useful:
>
> o Cheap
Hi
When one considers how much hardware one saves over a PIC solution,
the DSP is cheap. They are in the $10 range.
> o Simple to build by anyone with a few electronics skills.
A little tough here. 50 mil spaces surface mount. Some soldering
skills required.
> o Open 'source' (all schematics etc. available)
No issue here.
> o Easy / quick connectivity
Although, most computers come with a parallel port, using
the port on a newer XP for other than normal purposes may be a pain.
>
>Catweasel seems to lose out on 1, 3, and 4 - and 2 isn't relevant in its
>case. Can't comment on how nice its software API is as I haven't looked
>at it yet, but doubtless a bunch of us on this list could come up with
>something that'd cater for all tastes (plus the really low-level
>software would all be open source anyway!)
>
>Personally I'm not a fan of a USB version though; I'd rather have
>parallel as pretty much any machine has a parallel port - USB limits me
>to newer PCs and Macs (plus software interfacing *might* be harder).
>
>Priorities seem to me to be (highest first):
>
> o Reading disks
Should be easy.
> o Writing back a disk image
I see only minor issues here ( pre-comp )
> o Decoding disk data on host machine
Just requires some one to do it.
> o Modifying disk data on host machine, re-encoding back to floppy
If one can do the above, this one comes along, almost
for free.
Later
Dwight
>
>Happily, that's probably order of complexity too, easiest first :) (I am
>coming at this from a preservation point of view, rather than being able
>to create disk images for use with emulators, say)
>
>cheers
>
>Jules
>
>
NPR interview with Donald Knuth at http://tinyurl.com/5zs35 and community
efforts to save abandonware at http://tinyurl.com/5xk9p.
- Evan
Evan's personal homepage: www.snarc.net
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I am currently really enjoying "Fire in the Valley", and was reliving
the days when IMSAI reigned....
I learnt about the VDP-80 and how poor management chose to released
the not-fully-debugged VDP-80 into the public...
So anybody as a VDP-80? Until I read about it I've never head of it...
/wai-sun
Guess I might as well weigh in too. The first computer I worked with was a CDC 1604-A which uses the octal numbering scheme. I will be 102 in 5 days, the 19th of March.
Bill
Hi
I thought I should note here that all of the floppies
that I originally created years ago have been readable.
The only issues I've had with these is that the glue
used on some envelopes inner linings seeps through
the lining onto the disk or the envelope has been
pinch in a stack so long that the disk doesn't turn.
I've heard that the surfaces will begin to break down
but so far, none of my disk have shown that to be true.
My floppies go back to when ever the H89 first came
out ( within a year after anyway ).
I'd hoped that CDROMs could at least hold up that long.
It looks like I'll be disappointed soon.
Dwight
>From: "Vintage Computer Festival" <vcf at siconic.com>
>
>
>In case anyone cares, I ended up getting working that Videotrax card I
>wrote about a day ago. What might be useful to know is that I followed
>Dwight's advice and re-seated the only socketed chip on the board (that
>customy Motorola chip). After doing this everything seems to be working
>peachy. I'm more than halfway through dumping another 10 megabytes of
>data from one of the VHS data tapes I have; so far so good.
>
>New maxim: when all else fails, re-seat.
>
>--
>
>Sellam Ismail Vintage Computer Festival
>
Hi
Good to hear.
Dwight
>I believe you want something like the following (my notes aren't handy at
>the moment).
>SET DU0: UNIT=0,PART=0
>SET DU1: UNIT=0,PART=1
>SET DU2: UNIT=0,PART=2
>SET DU3: UNIT=1,PART=0
Although these will work, I have found that for purposes of simplicity,
and maximizing the ability to boot a given disk on multiple
configurations, it is best to use the lower DU unit numbers for physical
drives, and the higher ones for logical mappings.
So, for example, I would have
SET DU0 UNIT=0 PART=0
SET DU1 UNIT=1 PART=0
SET DU2 UNIT=2 PART=0
SET DU3 UNIT=3 PART=0
SET DU4 UNIT=0 PART=1
SET DU5 UNIT=0 PART=2
(when you use the 64-unit version of the driver, you're on your own...:-)
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL,ST| email: mbg at world.std.com |
| Member of Technical Staff | megan at savaje.com |
| SavaJe Technologies, Inc. | (s/ at /@/) |
| 100 Apollo Drive | URL: http://world.std.com/~mbg/ |
| Chelmsford, MA 01824 | "pdp-11 programmer - some assembler |
| (978) 256 6521 (DEC '77-'98) | required." - mbg KB1FCA |
+--------------------------------+-------------------------------------+
