--- On Thu, 7/2/09, Brent Hilpert <hilpert at cs.ubc.ca> wrote:
> Dave, on your web page you mention "Each board has an
> AY-3-1015D UART on board
> suggesting that the console serial port is built into the
> CPU". If you feel
> like tracing the interface connections from the UART
> (probably thru some 1488/9
> drivers), the datasheet for the 3-1015 is here:
> ? http://www.datasheets.org.uk/pdf/761571.pdf
Yes, I'll do that, partly because I'm curious about what sort of line drivers are on there. Didn't spot any of the usual suspects. Thanks for the link and the suggestion.
>
> It's a pin-config'd UART, so the config may also be
> discernible from examination.
>
There is a wealth of jumpers around the UART that I assumed were for setting the console line attributes but if I trace them back to the UART I can verify their purpose.
Regards,
-Dave
Hi! I recently had some S-100 prototyping boards made and I have some
extras.
If anyone would like to buy some please contact me by email.
Thanks and have a nice day!
Andrew Lynch
I'm just in the midst of rebuilding a PDP-8/M which has the H740 PSU in
it (also fitted to 5.25" PDP-11/05s).
I've cleaned the PSU up and reformed its capacitors, checked the
transformer is working fine. On replacing the switch mode circuit board
and powering up, I'm getting a blown fuse (F1 on circuit diagram) which
supplies the 5V and 15V rails. The -15V rail is working fine.
Does anyway have any suggestions as to the best approach to locating the
problem? I've been pondering whether it would be possible to isolate
either the 5V or 15V circuit so I can see which of them is causing the
problem, but I can't see any simple way to achieve this.
Also, is my practice of powering the PSU up without any load a foolish
one? I've not had any problems in the past using this approach but I
have seen people previously mention that running switch modes without a
load is a bad idea.
A circuit diagram of the H740 can be found here:
http://highgate.comm.sfu.ca/~djg/htdocs/cgi-bin/tifftopdf.cgi/h740.pdf?loc=…
Thanks,
Toby
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Will a Kaypro really play nice with a 3.5" floppy drive? It never
occurred to me to try it. I thought the floppy drivers under CP/M only
knew about DD drives, and the bios on the boot disk was different
between the various Kaypro models among other things to support the
different floppies they had (SS/SD, SS/DD, DS/DD).
Tom
FInally I could extract the information of the Altos 586 disks which I
mention some weeks ago. The fact was to convert the IMD files in BINARY
images. Then you can access them with the 'tar' command.
It works, but... the cobol set which was what I was searching comes only
with one disk, but they are TWO. You can note it when decompress the
existent disk with 'tar' in the Altos System in raw and noraw mode, and it
tell you:
"please, insert tape/disk number 2; then type 'y <return>' "
If you 'untar' the tar files in one pc and review the readme files you can
see too the fault of some important files as the COBOL compiler itself.
The question is: Some opportunity to obtain the lost second COBOL disk ?
Thanks
Regards
Sergio
--- On Thu, 7/2/09, Tobias Russell <toby at coreware.co.uk> wrote:
> I've cleaned the PSU up and reformed its capacitors,
> checked the
> transformer is working fine. On replacing the switch mode
> circuit board
This looks like a linear PSU to me.
> and powering up, I'm getting a blown fuse (F1 on circuit
> diagram) which
> supplies the 5V and 15V rails. The -15V rail is working
> fine.
> Does anyway have any suggestions as to the best approach to
> locating the
> problem? I've been pondering whether it would be possible
> to isolate
> either the 5V or 15V circuit so I can see which of them is
> causing the
> problem, but I can't see any simple way to achieve this.
Based on my limited experience:
Start by checking the bridge rectifier D14.
The +5V line has overvoltage protection via Q11 and D12. It may be crowbarring the 5V line causing F1 to blow.
Did you verify the condition of the big cap C7 with an ohmmeter ? Make sure it's discharged and then measure the resistance across it. It should start at zero and climb slowly and steadily upwards.
I'd also look around Q6 for a collector-emitter short, and Q7 for a short.
>
> Also, is my practice of powering the PSU up without any
> load a foolish
> one? I've not had any problems in the past using this
> approach but I
> have seen people previously mention that running switch
> modes without a
> load is a bad idea.
A dummy load may be useful as you get further into testing; you'll want to be sure that the outputs are functioning correctly under load.
Regards,
-Dave
--- On Thu, 7/2/09, Jim Brain <brain at jbrain.com> wrote:
> OK, for the record, I saw the app. But, I made an
> assumption that I
> need a PC drive.
>
PC's use standard Shugart-style interface floppy drives, just like most other computers of the era. You'll find that most machines have compatible disk drives - Kaypro, Osborne, TRS-80, IBM PC, TI-99/4A (in the expansion unit), etc, etc.
The "oddballs" like the C64, Apple II, Atari, and other micros are all different though.
The primary difference between other machines and PC's is the drive select line. PC's have all the disk drives jumpered as the second drive (drive 1), and use a cable with a twist in it to swap the select line around to turn a drive jumpered as drive one into drive zero. Most other machines just use the drive select jumpers on the drive itself.
As for a cable, you should only need a regular PC floppy cable, with the card edge style connectors as well. Find one of the long ones, Gateway full tower machines used to come with really long floppy cables. And the cables for older machines used to have both card edge and dual row pin type connectors for both 5 1/4" drives and 3 1/2" drives. You should be able to unplug the data cable from the Kaypro drive, and plug it into the PC cable. You can leave the drive in the Kaypro, and leave it connected to the Kaypro for power - and just hook the cable up to the PC. If you use drive zero, then plug it in with the non-twisted connector, and the PC should use it as Drive A. If you use drive one, plug it in with the twisted connector, and it'll be drive A.
-Ian
--- On Thu, 7/2/09, Dave Dunfield <dave09 at dunfield.com> wrote:
> > Hmm, the PCs with the 5.25" drives, they not so
> present around here... :-)
>
> Hmm... but you do have a PC I assume.... and 2 5.25" drives
> sitting there in
> the Kaypro --- there must be a way to do it, Hmm....
Hmm.... and if only there was some sort of really clever software that could write disk images out to real floppy disks. And perhaps then even a wonderfully useful archive of diskette images. If only...
<grin>
http://www.classiccmp.org/dunfield/img/
-Ian
--- On Wed, 7/1/09, ics65 at sbcglobal.net <ics65 at sbcglobal.net> wrote:
> I only have experience with the Nova
> 4 Jr. CPU and Nova 3, both without the Battery Backup,
> Memory Management or Multiple/Divide options. The Nova 4 Jr.
> CPU had 64k byte of memory in the front left corner of the
> CPU pcb. It does have the virtual terminal that connects to
> an external terminal. This replaced the paddle switch
> functions of the Nova 3.
George, thanks. If the Nova 4 Jr. CPU is marked 'DCG JR. CPU' in the front right-hand corner (and it's a pretty good bet), then that's probably what I have and I'll confirm by looking for those memory chips.
Am I right in thinking that the console terminal connection is made through pins on the backplane as there is apparently no socket on the board for this purpose ?
Regards,
-Dave?
--- On Thu, 7/2/09, George Wiegand <ics65 at sbcglobal.net> wrote:
> The console terminal connection maybe
> labeled directly on the backplane (a row of ~10 pins), only
> 3 pins for the RS232 are needed. I guess you don't have the
> info. to the pin outs?
I'll have to take a closer look tonight at what is on the backplanes. I had thought that both machines were the same but I'm realizing that they are slightly different; only one has the JR. cpu, the other one is marked DGC 12V0.
I don't have the wiring details for the backplane console pins but there's a good chance it's already wired on one of the chassis; there are two 25-way D type connectors on a bracket on the right hand side of the back of the chassis.
My experience with Novas began and ended with the 1200's and 1220's, and the UK Redifon Computer offshoots in the early eighties, so I'm completely unfamiliar with the console arrangements for the newer CPUs (actually I'm completely unfamiliar with the new CPUs, period).
> Dave, what part of the world are you located in?
> ,George
Eastern Pennsylvania, near the town of New Hope, right on the NJ border.
Regards,
-Dave
