Hope you all had a very merry Christmas, happy Hanukkah, or whatever you
celebrated! Also, best wishes for the New Year, which will be... in
around two and a quarter hours in my neck of the woods :)
It's been a while since I posted anything related to DiscFerret. Rest
assured, I have not been resting on my laurels (Balrog and Lord
Nightmare have made certain of that!). In fact, I've just released a
shiny new toy for all you DiscFerret owners... Well, two actually!
Microcode Release 0026 and C-API 1.3!
New in these releases...:
- Added a clock divider to the Data Acquisition core. Now you can
specify how much timing resolution you need -- 80ns (12.5MHz), 40ns
(25MHz), 20ns (50MHz) or the full 10ns (100MHz). When set to 40ns, the
DiscFerret matches the Kryoflux for read speed (84 tracks double-sided
in one minute and 45 seconds). At full resolution, it still only takes
three minutes and 25 seconds to image the same disc.
- Completely rewrote the data sync-word detector. All the ripple
clocks and clock-domain crossings are gone, and the data separator is
FAR more reliable. The capture and lock range is about 20% of the
nominal data rate (!), which is more than adequate for most disc drives.
The sync word may be up to 16 bits long, and can also include "don't
- Miscellaneous fixes to the data separator configuration (it was
set for a 16MHz clock, but provided with a 20MHz clock. Despite this, it
still worked fine!)
- C/C++ API
- Support added for the new clock divider register.
Files are all downloadable from the usual place --
(or more specifically:)
And you can, as always, browse the source code here --
On the cards for the New Year --
- Work has started on a new, simplified API. This will make its grand
d?but some time in the new year.
- I'm working on improving the accuracy of the INDEX pulse storage
logic. When finished, this will improve the accuracy of INDEX timing
measurements to match the data timing measurements! (This is a minimum
of a factor of 8 improvement over the KryoFlux analyser, and a factor of
128 improvement over the current microcode release!)
Special thanks for this release are due to:
... and anyone else I've forgotten!
classiccmp at philpem.me.uk
Like the Sanyo just yesterday, I have a Compaq SLT/286 portable computer
taking up space. Very nice condition, with power unit, dock, and bag. Any
interest CHEAP? I am located in New York, zip 10512.
Unlike the Sanyo, if there is no interest, I suppose I will just chop this
I am desperately trying to clear out a bedroom to work on it - the bedroom
that ends up being the junk overflow containment chamber. It would
actually be nice to sleep in it sometime.
aw288 at osfn.org
I have a PDP 11/03 that used to be part of the startup for an 11/780 at
the University of Arkansas at Fayettville. The 780 has long ago been
So, the 11/03 has the following boards:
M8017-AA : DLV11-E/EC Single-line async control module (Replaces
M8017,M8017-YB) Renamed DLVE1
M7940 : DLV11 Serial Line Unit (SLU, Async)
M7944 : MSV11-B 4-Kword 16-bit MOS RAM
M7946 : RXV11 RX01 8" floppy disk controller
M9400-YE : Bootstrap terminator
I also have the RX01 drive. So, other than media, what other options do
I need to get this running as an 11/03? Where is the best place to get
some basic media images? Is it possible to create boot media on the 8"
drives I have connected to my PC using IMAGEDISK, 22DISK or the
I know a lot of these questions are answered out there, but I've not
seen (yet) a simple step by step to get one of these running.
I have the opportunity to get a couple of memory boards also:
M8044-DB 32K, 16-BIT RAM for LSI-11
M8044-DE 32K, 16-BIT RAM for LSI-11
So, will these work with this 11/03? It seems they will, but I was
looking for verification.
Thanks for any help, and of course the associated "have you tried
I wouldn't mind moving a few more copies out of this stack of 100 freshly printed books! So I'm knocking $3 off and it's shipped free in the US ($3 off international shipping).
David Greelish, Computer Historian
- Author, "The Complete Historically Brewed"
- Founder, Atlanta Historical Computing Society
- "Classic Computing Show" podcast
- "Stan Veit's History of the Personal Computer" audiobook podcast
- "Retro Computing Roundtable" podcast
ClassicComputing.com | atlhcs.org
Does anyone have the O/S, Applications, and Diagnostice disks for this
ancient IEEE 488 bus controller (Fluke 1720A)? It used a TI 9900
processor if I remember correctly. The operating system was called FDOS-
a custom effort too I think, distributed on three 5 1/4" floppies. This
is no longer available from anywhere or anyone, including Fluke.
Thanks for any help and/or leads.
I have been fortunate to acquire a Kaypro system that appears to be in
great condition and looks to work.
It looks exactly like this:
Thus, it says Kaypro 1 on the artwork
Still, the sticker on the rear says Kaypro 2, so I'm confused.
In any event, I have no system disks for it (There is a slight
possibility they are part of the stash with which the Kaypro was
bundled, but it's 100 sq ft of stuff). Thus, I'm wondering if there is
a kind soul who might be able to ship me a set of disks. (I'll pay
shipping, of course).
I also am the proud owner of 2 Obsorne machines (one works, the other
seems to have drive issues. They are the redesigned units, but (as I
suspected) the systems disks won't work on the Kaypro.
Jim Brain, Brain Innovations (X)
brain at jbrain.com
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
A while back, I mentioned that I'd found and potentially fixed the "bricking" problem with the CQD-220.
To recap, for those that werent following, the problem lies in the code for the on-board 8086 when you set the number of both disks and tapes to zero. The 8086, during its routine to load the values from the EEPROM, loads the total number of disks and tapes and executes a loop with a counter predecrement; if the counter is loaded as 0, it effectively runs through the loop 256 times instead of 7 (the max), which spins out of control and blows away some RAM somewhere before crashing.
Fortunately, through a compiler bug or some such, there are 5 bytes available from a totally redundant instruction (loading a value into a register where the same value is already loaded) in just the right place to test the total number of devices and jump to the "uninitialized device table in EEPROM" section of the routine if it is zero. With one byte to spare! (good thing NOP is only a byte in 8086)
This applies to the A7A revision of the ROM, anyway; I haven't gotten to the A8 version yet, though I know it exhibits the same bug. Hopefully it also has the same redundant instruction. In any case, I should be able to find and fix it quickly once I have the time, because I know where to look.
So, here's the thing; I've finally gotten the time to test the fixed ROM image (was temporarily short of 27256 chips, but that's been resolved) and I'd like to get the fixed images somewhere they'll be easy to find if anyone else runs into the same problem (this took me over a year of sporadic attention to fix). Does anyone know where I should post this? There's my own website, which is really not a thing anymore, but there are probably lots of places Google is more likely to find.
Also, are there copyright implications to consider? I know CMD is long gone, but I still worry about these things.
Last thing: does anyone know the difference between the A7A ROM and the A8? I've not found anything different; I assume it's probably an obscure bugfix.
The images are only 64K total, so I shouldn't imagine they'll be bandwidth intensive.
It's running! Telnet to 188.8.131.52 to take a look and help me test it.
You can use the standard Windows telnet program, Putty, Linux, or
whatever you have handy.
Around 10 users can be on at the same time. When you sign on (no
password required) there will be a little menu to help you waste some
time. Some things you can do are see who else is on the server, view the
machine type, ROM BIOS date and DOS version, check the TCP/IP statistics
to see how much traffic it is handling, etc.
There are some upgrades since the last time I ran this test (in Dec 2007):
- The TCP/IP stack is much better
- I'm doing 'telnet' negotiation to figure out the terminal type, turn
echoing on, etc
- Crude line editing has been added
Right now it is running on my PCjr using a Xircom PE3 10BT. I plan to
leave it up as long as it runs, or three days, whichever comes first. It
is a PCjr so if there is a momentary delay, don't panic - it's probably
just doing disk I/O.
Backspace is a little dodgy .. it really wants ASCII 8 and a lot of
terminals and emulators do ASCII 127 instead. Try variations with the
shift and control keys if it doesn't work.