[cctalk] Re: datapoint 2200 programming

[jos via cctalk]

On 12.10.22 22:54, Steve Lewis via cctalk wrote:

Does anyone know how the 1970/1971 original Datapoint 2200 was programmed?
It had tapes containing terminal programs to access different types of
systems.  And the instruction set was said to be similar what became the
8008.   But how were these terminal programs created and how were the tapes
written?Were they under emulators on larger systems, like a PDP-10?
  Were there any tapes that had something like a machine code editor and
tape-write routines?  I assume no kind of ROM was built into the system
(unless it had a built in machine code editor, and routines to write that
content to a tape?)   Was a version of BASIC ever built for the 8008 that
ran on a Datapoint 2200 or similar system?

-Steve


Look here to wat was available for this class of machines :

http://www.bitsavers.org/pdf/datapoint/software/6_Datapoint_Software_Catalog_Sep1982.pdf


So, yes, Basic, RPG, Cobol ( for 5500 upwards), Databus, Datashare, Dataform 
were available.

Programs development could be done standalone, even on a cassette-only system.

Keep in mind that Diablo 14" diskdrives were available for these system, 
allowing for quite a comfortable environment. For early 70's standards of course...

My DP2200 does have a bootrom, allowing for booting from floppy, or some 
simnple ad-hoc systems debugging. Look for the deocumented source code for this 
bootrom on Bitsavers.


Jos

[cctalk] Xerox 820II U07 Power Supply magic smoke....

[D. Resor via cctalk]

Where might I find a schematic diagram for the Xerox U07 8" FDD,HDD
expansion cabinet for the 820II, and/or the 105P80450 power supply?

The Xerox Professional Computer Technical Reference Manual I downloaded from
bitsavers.org doesn't seem to have those particular schematic diagrams.

For your enjoyment the part which smoked.

https://www.dropbox.com/s/al9kx3yw9ypwp89/Xerox105p80450.jpg?dl=0

I certainly am glad I have the lid off while testing.  Unfortunately these
capacitors which appear to be film type were hidden from view.  

The fuse didn't blow, but that .22uf 250v capacitor certainly stunk up the
house.  It smelled like burnt popcorn, plastic and the bottom of a coffee
pot which has boiled dry, yech!

I know that if I had pulled the power supply board first I might have seen
the physical cracks in these boxed capacitors.

Wasn't it Marc V. that said in one of his videos, you don't need to shotgun
them all! Oi, lol

It's when things like this happen that I most always worry about not going
over vintage equipment fine tooth comb.

Don Resor

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[Joshua Rice via cctalk]

You shouldn't need a schematic. These thin film caps are a common 
failure mode on a multitude of PSUs. Just replace like for like. Thin 
film X and X2 rated caps are easily found from your favorite electronics 
part retailer.


If it's gold and got RIFA on it, replace it, though. Just because it 
hasn't popped, doesn't mean it wont pop in the near future.


I've learned now, to always check every PSU or other mains-powered 
vintage equipment for these little stinkbombs. If they're present, i'll 
always replace.


Cheers, Josh

-- Original Message --
From: "D. Resor via cctalk" 
To: "Classic Computer Mailing List" 
Cc: "D. Resor" 
Sent: Thursday, 13 Oct, 2022 At 12:24
Subject: [cctalk] Xerox 820II U07 Power Supply magic smoke
Where might I find a schematic diagram for the Xerox U07 8" FDD,HDD
expansion cabinet for the 820II, and/or the 105P80450 power supply?
The Xerox Professional Computer Technical Reference Manual I downloaded 
from

bitsavers.org doesn't seem to have those particular schematic diagrams.
For your enjoyment the part which smoked.
https://www.dropbox.com/s/al9kx3yw9ypwp89/Xerox105p80450.jpg?dl=0 

I certainly am glad I have the lid off while testing.  Unfortunately 
these

capacitors which appear to be film type were hidden from view.
The fuse didn't blow, but that .22uf 250v capacitor certainly stunk up 
the
house.  It smelled like burnt popcorn, plastic and the bottom of a 
coffee

pot which has boiled dry, yech!
I know that if I had pulled the power supply board first I might have 
seen

the physical cracks in these boxed capacitors.
Wasn't it Marc V. that said in one of his videos, you don't need to 
shotgun

them all! Oi, lol
It's when things like this happen that I most always worry about not 
going

over vintage equipment fine tooth comb.
Don Resor

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[Jonathan Chapman via cctalk]

> If it's gold and got RIFA on it, replace it, though.

- snip -

> I've learned now, to always check every PSU or other mains-powered
> vintage equipment for these little stinkbombs. If they're present, i'll
> always replace.

Yup, always replace. These are not parts that can be rehabilitated. RIFAs are 
one of the few things we always bulk replace without any sort of testing.

Thanks,
Jonathan

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[D. Resor via cctalk]

I do understand that these are common film capacitor types.  There is one more 
smaller .10ufa RIFA branded capacitor hiding near the center of the PWB.  

A couple reasons I'd like to have a circuit diagram is to know what the RIFA 
capacitors purpose are.   The other is, a couple of the electrolytic capacitor 
are double covered with what appears to be rubbery heat shrink tubing, 
therefore I cannot read what their value are.  

One of these two electrolytic capacitor appears to have a dried substance 
around the top.  The over-pressure venting cuts in the top of these two 
capacitors are not split.  At this point I cannot tell if it is dried 
electrolyte, cement to hold the sleeve on, or possibly paper.

Looking at these two again, it definitely could be dried electrolyte.  I have 
seen it creep out and up into strange places.

https://www.dropbox.com/s/18hzfdqe96vmgsr/electrolytics.jpg?dl=0

Seems someone was in hurry on the day this PS was tested.  I cannot make out 
date, is it 1983?

https://www.dropbox.com/s/zlt2ocpqulil13j/pssticker.jpg?dl=0 

What type are the diodes, their rating etc.?  I seem to remember this type with 
a black band were rated at 3 amps, but that's all I remember.

The TO-3 transistor/regulator has no P/N silkscreened on it.

Having a circuit diagram helps to cover many bases.  Apparently it's an Astec 
AA12070.

Placed the PS board back in the garage to continue airing out! 😉

Don Resor





-Original Message-
From: Joshua Rice via cctalk  
Sent: Thursday, October 13, 2022 4:43 AM
To: General Discussion: On-Topic and Off-Topic Posts 
Cc: Joshua Rice 
Subject: [cctalk] Re: Xerox 820II U07 Power Supply magic smoke


You shouldn't need a schematic. These thin film caps are a common failure mode 
on a multitude of PSUs. Just replace like for like. Thin film X and X2 rated 
caps are easily found from your favorite electronics part retailer.

If it's gold and got RIFA on it, replace it, though. Just because it hasn't 
popped, doesn't mean it wont pop in the near future.

I've learned now, to always check every PSU or other mains-powered vintage 
equipment for these little stinkbombs. If they're present, i'll always replace.

Cheers, Josh

-- Original Message --
From: "D. Resor via cctalk" 
To: "Classic Computer Mailing List" 
Cc: "D. Resor" 
Sent: Thursday, 13 Oct, 2022 At 12:24
Subject: [cctalk] Xerox 820II U07 Power Supply magic smoke
Where might I find a schematic diagram for the Xerox U07 8" FDD,HDD expansion 
cabinet for the 820II, and/or the 105P80450 power supply?
The Xerox Professional Computer Technical Reference Manual I downloaded from 
bitsavers.org doesn't seem to have those particular schematic diagrams.
For your enjoyment the part which smoked.
https://www.dropbox.com/s/al9kx3yw9ypwp89/Xerox105p80450.jpg?dl=0

I certainly am glad I have the lid off while testing.  Unfortunately these 
capacitors which appear to be film type were hidden from view.
The fuse didn't blow, but that .22uf 250v capacitor certainly stunk up the 
house.  It smelled like burnt popcorn, plastic and the bottom of a coffee pot 
which has boiled dry, yech!
I know that if I had pulled the power supply board first I might have seen the 
physical cracks in these boxed capacitors.
Wasn't it Marc V. that said in one of his videos, you don't need to shotgun 
them all! Oi, lol It's when things like this happen that I most always worry 
about not going over vintage equipment fine tooth comb.
Don Resor

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[Jonathan Chapman via cctalk]

If the PSU requires too much hacking, you may just want to replace with a 
modern Mean-Well switcher or two. The Aztec supplies used in those Xerox 
enclosures are OK but nothing stellar. I recapped mine (it also showed signs of 
electrolytic leakage) and it did work so I kept it, but if it'd had issues I'd 
have junked it.

Thanks,
Jonathan




--- Original Message ---
On Thursday, October 13th, 2022 at 09:32, D. Resor via cctalk 
 wrote:


> 
> 
> I do understand that these are common film capacitor types. There is one more 
> smaller .10ufa RIFA branded capacitor hiding near the center of the PWB.
> 
> A couple reasons I'd like to have a circuit diagram is to know what the RIFA 
> capacitors purpose are. The other is, a couple of the electrolytic capacitor 
> are double covered with what appears to be rubbery heat shrink tubing, 
> therefore I cannot read what their value are.
> 
> One of these two electrolytic capacitor appears to have a dried substance 
> around the top. The over-pressure venting cuts in the top of these two 
> capacitors are not split. At this point I cannot tell if it is dried 
> electrolyte, cement to hold the sleeve on, or possibly paper.
> 
> Looking at these two again, it definitely could be dried electrolyte. I have 
> seen it creep out and up into strange places.
> 
> https://www.dropbox.com/s/18hzfdqe96vmgsr/electrolytics.jpg?dl=0
> 
> Seems someone was in hurry on the day this PS was tested. I cannot make out 
> date, is it 1983?
> 
> https://www.dropbox.com/s/zlt2ocpqulil13j/pssticker.jpg?dl=0
> 
> What type are the diodes, their rating etc.? I seem to remember this type 
> with a black band were rated at 3 amps, but that's all I remember.
> 
> The TO-3 transistor/regulator has no P/N silkscreened on it.
> 
> Having a circuit diagram helps to cover many bases. Apparently it's an Astec 
> AA12070.
> 
> Placed the PS board back in the garage to continue airing out! 😉
> 
> Don Resor
> 
> 
> 
> 
> 
> -Original Message-
> From: Joshua Rice via cctalk cctalk@classiccmp.org
> 
> Sent: Thursday, October 13, 2022 4:43 AM
> To: General Discussion: On-Topic and Off-Topic Posts cctalk@classiccmp.org
> 
> Cc: Joshua Rice ric...@btinternet.com
> 
> Subject: [cctalk] Re: Xerox 820II U07 Power Supply magic smoke
> 
> 
> You shouldn't need a schematic. These thin film caps are a common failure 
> mode on a multitude of PSUs. Just replace like for like. Thin film X and X2 
> rated caps are easily found from your favorite electronics part retailer.
> 
> If it's gold and got RIFA on it, replace it, though. Just because it hasn't 
> popped, doesn't mean it wont pop in the near future.
> 
> I've learned now, to always check every PSU or other mains-powered vintage 
> equipment for these little stinkbombs. If they're present, i'll always 
> replace.
> 
> Cheers, Josh
> 
> -- Original Message --
> From: "D. Resor via cctalk" cctalk@classiccmp.org
> 
> To: "Classic Computer Mailing List" cctalk@classiccmp.org
> 
> Cc: "D. Resor" organlis...@sonic.net
> 
> Sent: Thursday, 13 Oct, 2022 At 12:24
> Subject: [cctalk] Xerox 820II U07 Power Supply magic smoke
> Where might I find a schematic diagram for the Xerox U07 8" FDD,HDD expansion 
> cabinet for the 820II, and/or the 105P80450 power supply?
> The Xerox Professional Computer Technical Reference Manual I downloaded from 
> bitsavers.org doesn't seem to have those particular schematic diagrams.
> For your enjoyment the part which smoked.
> https://www.dropbox.com/s/al9kx3yw9ypwp89/Xerox105p80450.jpg?dl=0
> https://www.dropbox.com/s/al9kx3yw9ypwp89/Xerox105p80450.jpg?dl=0
> 
> I certainly am glad I have the lid off while testing. Unfortunately these 
> capacitors which appear to be film type were hidden from view.
> The fuse didn't blow, but that .22uf 250v capacitor certainly stunk up the 
> house. It smelled like burnt popcorn, plastic and the bottom of a coffee pot 
> which has boiled dry, yech!
> I know that if I had pulled the power supply board first I might have seen 
> the physical cracks in these boxed capacitors.
> Wasn't it Marc V. that said in one of his videos, you don't need to shotgun 
> them all! Oi, lol It's when things like this happen that I most always worry 
> about not going over vintage equipment fine tooth comb.
> Don Resor
> 
> 
>

[cctalk] Re: datapoint 2200 programming

[Dave Mitton via cctalk]

>   Date: Wed, 12 Oct 2022 15:54:33 -0500
>   From: Steve Lewis 
>   Subject: [cctalk] datapoint 2200 programming
>
>   Does anyone know how the 1970/1971 original Datapoint 2200 was 
> programmed?
>   It had tapes containing terminal programs to access different types of
>   systems.  And the instruction set was said to be similar what became the
>   8008.   But how were these terminal programs created and how were the 
> tapes
>   written?Were they under emulators on larger systems, like a PDP-10?
>Were there any tapes that had something like a machine code editor and
>   tape-write routines?  I assume no kind of ROM was built into the system
>   (unless it had a built in machine code editor, and routines to write 
> that
>   content to a tape?)   Was a version of BASIC ever built for the 8008 
> that
>   ran on a Datapoint 2200 or similar system?
>
>   -Steve

While in college, 1973 to 77, I had a part-time job where one of the things we 
did was use a Datapoint 1100 dual cassette model to act as a data entry 
terminal for a database system running on a Cascade 80 minicomputer.

I did the Datapoint programming, which was to query the db over an async line 
for a form template, allow the operator to fill in the form, then upon entry, 
send the data back.  The db would provide the next form to display.A 
rudimentary state machine at several levels.

The Datapoint came with a Cassette Tape operating system, called CTOS I 
believe.  You booted it up, and the second drive was your working drive.  The 
Programmer’s manual referenced shows you the commands.  There was an simple 
tape file system, Editor, Assembler, Debugger, and a library of subroutines for 
common access to the system’s I/O.

I remember very little about the details of working on it, but I had no 
problems getting the data entry system working.  You just sat down and started 
programming it.   The instruction set was the model for the 8008, but it 
preceded the popularity and availability of that chip.

My boss did some real inspired work on the Cascade Data side.   He managed to 
insert the database access code into high memory of the system, and hook into 
the native OS.  So we could use the system normally, but the database serviced 
the terminal in the background.  I did other Cascade programming in assembly, I 
wrote my own instruction card for the system.

In my senior year, the facility switched over to using IBM System 3 equipment, 
and I got to work with RPG, 8-inch diskettes, and 96-column cards.

Dave.

Sent from Mail for Windows

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[Jon Elson via cctalk]

On 10/13/22 08:32, D. Resor via cctalk wrote:

I do understand that these are common film capacitor types.  There is one more 
smaller .10ufa RIFA branded capacitor hiding near the center of the PWB.

A couple reasons I'd like to have a circuit diagram is to know what the RIFA 
capacitors purpose are.   The other is, a couple of the electrolytic capacitor 
are double covered with what appears to be rubbery heat shrink tubing, 
therefore I cannot read what their value are.


Cut the heat shrink with an X-acto knife and peel it off.  
it should leave the marking of the cap intact.  if there are 
2 layers, it may be the inner layer is the original factory 
marked wrapper for the cap.  So, you might try to not cut 
through the inner layer.  But,, maybe don't be too worried, 
as the caps definitely sound bad.


Jon

[cctalk] Re: Intel's i860, Cray-On-A-Chip

[Paul Koning via cctalk]

> On Oct 13, 2022, at 11:02 AM, emanuel stiebler  wrote:
> 
> On 9/28/2022 20:18, Paul Koning via cctalk wrote:
>> FWIW, I just tried building GCC 2.95.2 on my Linux system (Fedora Core 32, 
>> GCC 10.3.1.  It almost built, ran into an argument mismatch error message in 
>> something called "chill".  So if you want something that old it looks like 
>> you'll have to start by building a less ancient version, say 4.8 or so, and 
>> then use that to build the dinosaur.
> 
> Which switches/options did you use?
> Last weekend I spent some cycles to try ...

I cheated a bit.  My test was "can GCC V.old build at all".  So I tried a 
native build, not a cross-build.  Cross-builds have their own set of issues and 
it's been long enough that I no longer remember them well.  That's what I would 
suggest when dealing with old versions: first try a native (or i386 if you have 
x86_64) build to see what, if any, issues you need to handle just for the 
generic old GCC.  Given that you have that working, you can then do the 
cross-build.  For example, if you need a GCC V.medium to build the GCC 
V.ancient, discovering that first makes things easier.

Yes, you'd have to start by finding an old enough binutils that supports the 
target platform.  With that in place, you can then build gcc for that platform.

paul

> I can build the binutils around 2.32, emitting elf
> No luck at all, getting gcc to compile. Support for the i860 was removed very 
> early after 4.0, going back to 3.x versions fails as they can't compile on 64 
> bit systems. (and also never used ELF, but COFF?)
> 
> So stuck a little at the moment, I guess I have to install some linux 32 bit 
> version, and try again ...
> 

[cctalk] Re: Intel's i860, Cray-On-A-Chip

[emanuel stiebler via cctalk]

On 9/28/2022 20:18, Paul Koning via cctalk wrote:

FWIW, I just tried building GCC 2.95.2 on my Linux system (Fedora Core 32, GCC 10.3.1.  
It almost built, ran into an argument mismatch error message in something called 
"chill".  So if you want something that old it looks like you'll have to start 
by building a less ancient version, say 4.8 or so, and then use that to build the 
dinosaur.


Which switches/options did you use?
Last weekend I spent some cycles to try ...
I can build the binutils around 2.32, emitting elf
No luck at all, getting gcc to compile. Support for the i860 was removed 
very early after 4.0, going back to 3.x versions fails as they can't 
compile on 64 bit systems. (and also never used ELF, but COFF?)


So stuck a little at the moment, I guess I have to install some linux 32 
bit version, and try again ...

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[Chris Zach via cctalk]

Side thought: I had one of those blow up on a BA23 chassis a few months 
ago. When I opened the supply it was full of aluminum paper from the 
inside of the cap; glad it didn't short out any other components.


Remove and replace.

C


On 10/13/2022 11:01 AM, Jon Elson via cctalk wrote:

On 10/13/22 08:32, D. Resor via cctalk wrote:
I do understand that these are common film capacitor types.  There is 
one more smaller .10ufa RIFA branded capacitor hiding near the center 
of the PWB.


A couple reasons I'd like to have a circuit diagram is to know what 
the RIFA capacitors purpose are.   The other is, a couple of the 
electrolytic capacitor are double covered with what appears to be 
rubbery heat shrink tubing, therefore I cannot read what their value are.


Cut the heat shrink with an X-acto knife and peel it off. it should 
leave the marking of the cap intact.  if there are 2 layers, it may be 
the inner layer is the original factory marked wrapper for the cap.  So, 
you might try to not cut through the inner layer.  But,, maybe don't be 
too worried, as the caps definitely sound bad.


Jon

[cctalk] Re: 8" floppy diskettes themselves (was: 8" floppy diskette storage cases)

[Mike Stein via cctalk]

I've certainly got some for sale; mostly DS/DD but a few SS/SD as well. Can
your drive(s) handle DS/DD disks?

m

On Wed, Oct 12, 2022 at 11:12 PM Mike Begley via cctalk <
cctalk@classiccmp.org> wrote:

> With all the talk about 8" floppy diskette storage cases, I was wondering
> if anyone had any 8" floppy disks themselves they would be willing to sell?
>
> This winter I am hoping to start restoring an IMSAI 8080 I recently
> acquired, and while it came with one external 5.25" drive, it would be
> desirable to connect a "proper" 8" disk system to it as well.  However, the
> complete lack of the disks themselves makes that project more or less
> impractical even once I get hardware set up.  So before I even start that
> project, I'd love to pick up a collection of 8" media.  Years back I had an
> impressive collection of CP/M software on 8" floppies, but unfortunately,
> they were accidentally left behind in a move.  :-/
>
> -mike
>
>