> http://mysite.verizon.net/rtellason/pa020085.jpg
> I haven't seen the inside of one for a while, but this may be for a
> Fortune-32
> JAM or someone with a machine handy (Eric?) could confirm it.
Al - we have one of those machines here at the Personal Computer Museum
(pcmuseum.ca) - if you can give me a couple of days, I can confirm this if
nobody else has one handy.
I tend to look for the simpler explanations first.
If your keyboard was previously working,
the first place I would check is the MMJ
on the back of the terminal.
I've seen everything from malformed pins,
to corrosion, to spider webs, to dead bugs
inside RJ12 / RJ45 connectors.
Another point of failure is the?MMJ on the keyboard cable;
you can try removing that, and re-crimping it.
T
________________________________
Yo, Tony here (Sharkonwheels on VC)
Got any boards left? CPU board, ECB backplane, and (if ready) FDD/IDE board.
Tony
[snip]
-----REPLY-----
Hi Tony!
Thanks! Yes, I have several PCBs left. I have N8VEM SBCs, ECB backplanes,
and ECB bus monitor PCBs. I just received the ECB bus monitor PCBs and
haven't finished building mine yet. Some of the other builders are helping
out by taking the lead on the first ECB bus monitor for build and test phase
while I continue work on the Disk IO board.
The ECB backplanes are going fast which rather surprises me. I have only a
few left and am going to have to reorder. The builders who have ECB
backplanes seem to like them though.
The Disk IO prototype is working fine so I am writing up the schematic and
doing the PCB layout right now. I'll be posting the schematic and PCB
layout for some much appreciated peer review in the next few days. I am
still doing quality checking on them to make sure they are right. The IDE
portion looks OK but the FDC portion is complex and has me concerned. The
big difference between the prototype and the manufactured PCB will be
several option jumpers and a "feature" connector to help builders who want
8" drive support.
Thanks and have a nice day! Please contact me offline if you'd like some
PCBs. They are still $20 each plus shipping.
Andrew Lynch
Would anyone have a service manual for the Hazeltine 1410 terminal ?
I have a peculiar problem where several keys output a different
character. I found there's a pattern to this chaos. From looking at the
ascii data, bits 5 and 6 become swapped only for characters between 40h
and 5Fh. instead of an 'A' it displays a '!" and it continues like
this. I'm afraid the i8243 chip might be bad but I'm not completely
sure. I found the i8243 datasheet and currently trying to trace the
connections. I hear this chip is hard to come by. I only found one
supplier so far which I'm waiting to hear back on the rfq.
thanks
=Dan
--
[ Pittsburgh 250th --- http://www2.applegate.org/~ragooman/ ]
2nd request
_____
Subject: cashtrac.exe ???
Dear sirs
I have been using cash Trac for a long long long time but my disk got
mutilated and would like to use this program again
Please advise how can I download this again for free
Look forward to your prompt reply
Eric
Hi Joe,
I found a really old post that you put up many years ago.
I am trying to get hold of an old Wicat 150ws or similar and was wondering if you knew of of anybody who has one and would like to sell it. Any info would be much appreciated.
Kind Regards,
Ben Christie
_________________________________________________________________
Z80 home brew with FDC
Eric Smith eric at brouhaha.com
<mailto:cctalk%40classiccmp.org?Subject=Z80%20home%20brew%20with%20FDC&In-Re
ply-To=200809220822.16872.thrashbarg%40kaput.homeunix.org>
Sun Sep 21 20:02:25 CDT 2008
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________________________________
Alexis wrote:
> The FDC-1 uses a FD179x controller and it appears it uses the same
> data clock and raw data inputs as the 765.
Not quite. I don't recall the details of the difference, but I think it
may have just been the polarity of one of the signals. The 9229 and
9239 had a configuration input to select between 179x and 765 modes.
The 9216 would directly connect to one, and needed a small amount of
logic (maybe just an inverter) for the other.
> The decoder is made up of a 74LS197 (clock divider), a dual 74LS74
flip-flop,
> both used, a 74LS163 counter and an inverter. There are also some open
> collector NAND gates to select the clock rate for either 8" or 5.25"
drives.
> It'll use more individual IC packages, but they're *much* easier to find.
Sure, but it doesn't sound like it's a very good data separator. The
good ones have a PLL (either analog or digital), because it is necessary
to track speed variations, not just of the drive that you're using to
read a disk, but also of the drive that wrote it. Non-PLL data
separators work OK when the disk is both written and read under optimal
conditions, but are unreliable otherwise.
The 9216, 9229 or 9239 are *highly* recommended, as they have a good
digital data separator. The 9229 and 9239 also contain write precomp
logic. The 9239 uses higher resolution timing for its PLL, so it may
perform better.
------REPLY------
Hi,
Eric is right about the FDC9229 being mode selectable between 179x and 765
modes. It makes a difference in a number of output frequencies, etc. Check
the datasheet. It is at the bitsavers.org URL I posted previously.
I can't speak to the PLL issue but Eric is consistent with what I have read
and heard previously. You can make data separator replacements from TTL but
the FDC9229 data separators are really good and provide more than just data
separation. They do a whole host of functions such as FDC clock, data
window, variable write precompensation, etc. I recommend them and they are
fairly easy to work with. They are not easy to find but they are available
if you look enough.
Is anyone interested in adding a 765 based FDC to their Z80 home brew
computer? This design is mostly done and just needs some road testing and
another set of eyes to check it out. The software is kind of crude but
working. There are only a couple of modifications left on the hardware.
First is to attach the FDC9229 write precompensation pins to the latch and
second is to connect the remaining two latch pins to FDC interface pin 2 and
34. The hardware will probably get finished this week some time. The
software will probably take a while though.
Tonight I read and wrote sectors on the IBM PC 360K 5.25" floppy disk. On
the same disk, I formatted some tracks so these functions seem to be working
in both DD and HD mode. Also verified with Catweasel that the 1.4M 3.5"
floppy disk is generating correct tracks. All the sector header information
is checking out right it seems.
BTW, when working on this FDC project, I cannot say enough good things about
the Catweasel. It is like have having x-ray vision into what is being
written to the disk and shows all sorts of hidden stuff. Very helpful when
you can check independently what the i8272 is doing compared to what it will
tell you it is doing.
Thanks!
Andrew Lynch
In going through my stuff I've come across some boards that may be of
interest. I've uploaded some pictures here:
http://mysite.verizon.net/rtellason/pa020085.jpg
I'm not sure what this is. The big ceramic cased device is an 8x300 series
part, maybe 8x305? I can double-check that if anyone's interested. The
rest of the board is generic TTL mostly.
http://mysite.verizon.net/rtellason/pa020086.jpg
http//mysite.verizon.net/rtellason/pa020087.jpg
This one I have no idea about, most of the 14/16-pin parts are generic
4000-series CMOS and the 8-pin parts appear to be linear chips, op amps and
such. The second pic is the panel on the left side of the first pic.
Then there's this one:
http://mysite.verizon.net/rtellason/pa020088.jpg
...a PMMI modem! I remember seeing that referenced a whole lot when I was
hacking away at CP/M comm programs, that seemed to be included in a bunch of
them.
Anybody interested in taking any of this stuff off my hands, feel free to
contact me offlist. On that last one in particular, I'd like to get
somewhat more than shipping costs. :-)
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Hi, All,
Since one of the first computers I ever got my hands on as a kid (Quest
Elf) happened to have TIL311 HEX displays, I've long been fascinated with
display technology of that vintage. I was poking around for images of
some of the related displays to the TIL311 and ran across a couple of
links with pictures and some history...
http://www.decodesystems.com/old-displays.htmlhttp://www.decadecounter.com/vta/tubepage.php?item=33
In particular, I notice that one of the displays I have one of is a
TIL305 or MAN2 (no logo on mine). I was also looking at the TIL306
or TIL308, but don't happen to have any of those.
I do have a reasonable quantity of TIL311s for my various Elf and Elf2000
machines and even a set that came with an INS8073 SBC. I would love to
find a couple more TIL305s so I can round out an old project, plus I had
an idea for a project that would be interesting to use TIL306s or TIL308s
(don't care about where the decimal point is, so either is acceptable),
but ISTR some discussion on the list a while back about those in particular,
possibly as replacements to some HP counter, and how difficult and
expensive they are to obtain.
TIL311s are frequently found on eBay for various prices; I've gotten
them myself for as little as $2.50 each in small quantities. I doubt
that TIL306s and TIL308s are anywhere near that inexpensive, no matter
what the quantity, but I thought I'd ask if anyone has recently found
any place selling them. I'm not trying to repair a bit of vintage kit,
so I'm not willing to pay "any" price for them - if they are too expensive
(as I suspect they are), then I will find some other display.
Yes, non-driven LEDs are inexpensive to free and modern microcontrollers
can drive wads of LEDs easily and cheaply, but what I'm going for is a
1970s look with 1970s components (i.e., popcorn-logic driven, not micro-
processor-driven). The advantage of the TIL306s and TIL308s is now what
it was then - a high level of integration reducing the overall wiring
complexity and parts count. The disadvantage now as then is that the
displays are more expensive than the entire rest of the device.
They still look cool, though, and that's the real point.
-ethan
--
Ethan Dicks, A-333-S Current South Pole Weather at 29-Sep-2008 at 22:20 Z
South Pole Station
PSC 468 Box 400 Temp -71.3 F (-57.4 C) Windchill -102.3 F (-74.6 C)
APO AP 96598 Wind 7.6 kts Grid 72 Barometer 683.5 mb (10496 ft)
Ethan.Dicks at usap.govhttp://penguincentral.com/penguincentral.html
