Hi folks,
I’m working on a vt220 debug/repair and have gotten to the point where I need to trace firmware execution at boot. I’ve managed to dump the proms (close to but slightly different from the versions in Lars’ GitHub) and the 8051 internal rom, and can load and disassemble these with the s51 simulator. I also have an HP 1660 logic analyzer successfully configured and clipped up to capture instruction traces.
I’m about to dive in to commenting the disassembly listings, but figured I’d ping here to see if anybody might have done this already in case I wouldn’t have to start from scratch?
thanks much,
—FritzM.
Note to those people too lazy to update their subject line... it is
REALLY getting tiresome looking for information about the SoCal VCF and
finding not one post giving any information about it let alone the
multitude of posts seemingly with the subject line "VCF SoCal"!!!
Sheesh!!! Kind of makes search totally (almost) useless.
I'm still not sure of the date(s) or location except that it is in
February somewhere in southern Orange County, CA USA.
I recently acquired a stash of 5.25” Northstar-related floppy disks. About half are soft sector for the Northstar Dimension, the other half are 10 sector for the Advantage 8/16.
There are, however, about a dozen 10 sector floppies all modified in the same curious way: they have had a write protect sticker stuck over the index hole. Some with the sticker on top, some on bottom; can’t think of any reason that would matter as blocked is blocked. But I’ll mention it.
They seem to have something to do with the Dimension, maybe, as a couple of them are marked with NetWare 1.1.1 related labels (all handwritten). There is a set of what appears to be WordPerfect install floppies (though they don’t say WordPerfect specifically) . A couple also mention the odd term “smutched”. One is actually labeled “smutch.exe”.
Tim Mann’s Catweasel tool (cw2dmk) was unable to find any valid sectors on them, using the option to ignore the index pulse. I am aware that some drives won’t enable data if the pulse is missing entirely but I used a drive that doesn’t care (Teac FD-55BR - I have used it to read unpunched “flippy” disks) and still got nothing.
Does the Dimension really not need the index pulse, despite otherwise using an apparently standard WD-style format? Is something else going on? Does any of this ring any bells with the collected wisdom of the list? What am I likely dealing with here, if I want to recover the contents of these disks?
Thanks.
ok
bear.
>
>The drive works perfectly for double sided disks (using the
>appropriate index hole).
Yea, 8" drives are a bit funny like that.
You know this, because context. Some future google-ologist might not.
So. 8" drives have a different index position for SS and DS.
In your case I suspect either the emitter LED or the receiver
phototransistor ro maybe the wiring or what ever conditioning on the
PCB is b0rken for the SS sensor.
Assuming of course your drive has two sensors -- I have not yet owned
an 8" drive like that, the ones I have had were dedicated SS or DS.
W
USA here, anyone have a Sharp x68000 keyboard and mouse to sell?
The one that I've repaired and am trying to complete is the desktop
version, black, mini-din connector.
--
: Ethan O'Toole
>I have found that computers are much like motorcycles: many of the
>most interesting were never available in the US.
Computers are much like motorcycles: many of the most interesting
ones were TERRIBLE!
W
On 1/31/2024 8:30 PM, mark audacity romberg via cctalk wrote:
> I suppose I should’ve specified “of the versions of BASIC I’ve ever heard anyone talk about still using this century.” :P
Basic09 is probably still in use on OS9000.
VAX BASIC is still in use on VMS ALPHA and Itanium and is about
to be released for the recent port of VMS to x86-64. I personally
know of a number of rather large production systems in VMS BASIC.
RSTS/E is harder to say. There are still a large number of PDP-11
sites running using both real hardware and commercial emulator
systems but which OSes they are using I can't say. Could be all
RT-11 and RSX-11. But then, BASIC-PLUS and BASIC-PLUS2 both run
on RSX-11 as well. I just don't have much experience with RSX-11
as I never really liked it.
And none of this takes into account hobbyists like me who use
all of them.
bill
I don't even have an APC anymore. But since this thing is eyeing me menacingly I figured I'd put the request out. Butler Flats Associates dual external 5 1/4" accoutrement, has it's own controller card (based on wd1771/1772 iirc). Contact me off list if you have these. Much appreciated.
Sent with [Proton Mail](https://proton.me/) secure email.
A quick note on ADM3a screen rot... my vintage collection resides in a cool
(60-72 degrees F) dry basement. My "pride and joy" ADM3a (I have several)
was just starting to show a few bubbles at the corners last September. I
was pulling out some parts units on Friday and noticed that one had a much
better screen than I remembered. Thinking that I might swap screens, I took
a close look at "PnJ" and discovered to my horror that most of the lower
half of the screen had "melted". "PnJ" was on a shelf, below eye level,
nowhere near a vent or other source of heat. I was so annoyed that I
immediately started cleaning/repair without taking any pictures (sorry).
Fortunately, there does not appear to be any corrosion from the "goo". I
completely desoldered and removed the keyboard assembly to get all of the
crud out of (and out from under) it. The mainboard is a fully socketed
example and the crud is down in several of the sockets. I'm still working
on that. Anyway, the take away is don't assume (like I did) that the ruined
ADM3as you see are the result of temperature extremes. It can happen
anywhere. Keep a close eye on yours if you have one.
Bill S.
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
