5 Dec
2017
5 Dec
'17
7:59 p.m.
From: Charles Dickman <chd at chdickman.com>
Subject: PDP8 ALGOL
I have been looking at the available software for the PDP8,
particularly languages. I see there was an ALGOL. The source is
archived on Bitsavers and dbit.
There is some information here:
http://www.softwarepreservation.org/projects/ALGOL/algol60impl/
Has anyone played with this before? Is there any additional
information on how to use it?
-chuck
I have looked at the 4k ALGOL described here:
http://www.bitsavers.org/pdf/dec/decus/pdp8/8-213_4K_ALGOL.pdf
The paper tape images are here:
http://www.bitsavers.org/bits/DEC/pdp8/papertapeImages/set3/
The RICM also has an original set of the DECUS 8-213 ALGOL paper tapes, but
they are different from the ones on Bitsavers. I need to make images of
these tapes.
Students at the UMN are trying to get ALGOL to run on their PDP-12 so they
can run some benchmarking software.
We haven't been able to get DECUS 8-213 ALGOL working. Any help would be
appreciated.
--
Michael Thompson
6 Dec
6 Dec
1:03 p.m.
From: Michael Thompson via cctalk: Tuesday, December 05, 2017 4:59 PM
The paper tape images are here:
http://www.bitsavers.org/bits/DEC/pdp8/papertapeImages/set3/
The RICM also has an original set of the DECUS 8-213 ALGOL paper tapes, but
they are different from the ones on Bitsavers. I need to make images of
these tapes.
When you do, I can perhaps help with the differences, if they are not too
major.
Students at the UMN are trying to get ALGOL to run on
their PDP-12 so they
can run some benchmarking software.
We haven't been able to get DECUS 8-213 ALGOL working. Any help would be
appreciated.
I got to the "OPT-" prompt, but after I enter "R", the simulation
hangs,
repeatedly taking an un-serviced interrupt.
It would be helpful to know which of the seven images are re-initialization
or patches, and which are part of the compiler and which the runtime.
Vince
9 Dec
9 Dec
6:52 p.m.
New subject: Epson PX-8 specifically TF-10 problem...
I have several Epson PX-8s and i used them.. They work well with the
various wedges I have.
I also Have a PF-10 which is the portable 3.5" 40 track two side floppy.
The problem is it randomly does not turn the media unless I give it a
push to get it turning.
Things checked:
* Batteries, NEW fully charge (Both).
* internal Power supplies, current voltage and bridged with external
?? supplies does not help.
* media checked for binding, it does not.
?When it turns it reads and writes correctly and at the correct speed.
?It may do so without help for many tries then will stop required a
manual push.
At first glance I though there were motor bearing issues but have verified
this is not so.?? If I force motor on and restrain it I has good torque
and no
dead spots.? All signals in the motor control look good on the scope.
Any thoughts?
Allison
7:52 p.m.
New subject: Epson PX-8 specifically TF-10 problem...
On Sat, 9 Dec 2017, allison via cctalk wrote:
I have several Epson PX-8s and i used them.. They work
well with the
various wedges I have.
I also Have a PF-10 which is the portable 3.5" 40 track two side floppy.
The problem is it randomly does not turn the media unless I give it a
push to get it turning.
Things checked:
* Batteries, NEW fully charge (Both).
* internal Power supplies, current voltage and bridged with external
?? supplies does not help.
* media checked for binding, it does not.
?When it turns it reads and writes correctly and at the correct speed.
?It may do so without help for many tries then will stop required a
manual push.
At first glance I though there were motor bearing issues but have verified
this is not so.?? If I force motor on and restrain it I has good torque
and no
dead spots.? All signals in the motor control look good on the scope.
Any thoughts?
How does it detect the presence of a disk? and/or disk change?
Totally irrelevant to the matter at hand:
BTW, how close to "industry standard" is the interface to the drive
mechanism itself? Would it be practical to replace the mechanism with
one of the 80 track (and also 2 sided?) Epson drives? Either the whole
drive, if it is fairly "standard", or just the stepping mechanism if there
is another Epson drive similar enough?
Besides significant increase in capacity, it would simplify data
interchange a bit.
Although the track spacing is 67.5 tpi, instead of 135tpi, I wonder
whether the track width is similarly different.
--
Grumpy Ol' Fred cisin at xenosoft.com
9:06 p.m.
New subject: Epson PX-8 specifically TF-10 problem...
On 12/09/2017 07:52 PM, Fred Cisin via cctalk wrote:
On Sat, 9 Dec 2017, allison via cctalk wrote:
Functions normally save for the motor does not always turn on command
but will if manually pushed.? All other functions are normal.
I have several Epson PX-8s and i used them.. They
work well with the
various wedges I have.
I also Have a PF-10 which is the portable 3.5" 40 track two side floppy.
The problem is it randomly does not turn the media unless I give it a
push to get it turning.
Things checked:
* Batteries, NEW fully charge (Both).
* internal Power supplies, current voltage and bridged with external
?? supplies does not help.
* media checked for binding, it does not.
?When it turns it reads and writes correctly and at the correct speed.
?It may do so without help for many tries then will stop required a
manual push.
At first glance I though there were motor bearing issues but have
verified
this is not so.?? If I force motor on and restrain it I has good torque
and no
dead spots.? All signals in the motor control look good on the scope.
Any thoughts?
How does it detect the presence of a disk??? and/or disk change?
Totally irrelevant to the matter at hand:
BTW, how close to "industry standard" is the interface to the drive
mechanism itself??? Would it be practical to replace the mechanism
with one of the 80 track (and also 2 sided?) Epson drives?? Either the
whole drive, if it is fairly "standard", or just the stepping
mechanism if there is another Epson drive similar enough?
No its an oddball.? The read-wirite electronics are part of the
intelligent mainboard that communicates
with the pX-8 serially.? The only board that is part of the drive is the
motor control.
Its of the early 80s.?? It would be nice to build a replacement with
more storage but the basic design
is a 68B03, 2732 and 765 with read/write amps and filter on that
board.??? It would be easier to start
from scratch with an 8085 and a 37c65 but then that
would require
figuring out the protocol and
patching the OS (CP/M-80 in Eprom) to accept the larger result.? If I
were to do that I'd do a solidstate
disk using CF or SD.? Its easier to do that using the PX-8 system bus
(parallel data, address and Z80 controls).
Besides significant increase in capacity, it would
simplify data
interchange a bit.
Although the track spacing is 67.5 tpi, instead of 135tpi, I wonder
whether the track width is similarly different.
Its not unlike the 5.25" situation with track width as in the the higher
density drives
have narrower heads.? Not unlike Sa450 and FD33GFR.? I can read the
media with
a standard drive by double stepping but to create media I have to first
bulk
erase and then write only every other track or it has a poor error rate.
Allison
9:14 p.m.
New subject: Epson PX-8 specifically TF-10 problem...
On 2017-Dec-09, at 6:06 PM, allison via cctalk wrote:
On 12/09/2017 07:52 PM, Fred Cisin via cctalk wrote:
How about a problem with the current supply to the motor, such as low gain in the driver.
A progressive failure may be just on the edge of supplying enough current to keep it
rotating, but not enough for startup torque.
On Sat, 9 Dec 2017, allison via cctalk wrote:
Functions normally save for the motor does not always turn on command
but will if manually pushed. All other functions are normal. I have several Epson PX-8s and i used them.. They
work well with the
various wedges I have.
I also Have a PF-10 which is the portable 3.5" 40 track two side floppy.
The problem is it randomly does not turn the media unless I give it a
push to get it turning.
Things checked:
* Batteries, NEW fully charge (Both).
* internal Power supplies, current voltage and bridged with external
supplies does not help.
* media checked for binding, it does not.
When it turns it reads and writes correctly and at the correct speed.
It may do so without help for many tries then will stop required a
manual push.
At first glance I though there were motor bearing issues but have
verified
this is not so. If I force motor on and restrain it I has good torque
and no
dead spots. All signals in the motor control look good on the scope.
Any thoughts?
How does it detect the presence of a disk? and/or disk change?
10 Dec
10 Dec
7:26 a.m.
New subject: Epson PX-8 specifically TF-10 problem...
On 12/09/2017 09:14 PM, Brent Hilpert via cctalk wrote:
On 2017-Dec-09, at 6:06 PM, allison via cctalk wrote:
That was my thought and I checked, not the problem.? I suspect that the
magnets in the rotor
have gotten really weak.
Allison
On 12/09/2017 07:52 PM, Fred Cisin via cctalk
wrote:
How about a problem
with the current supply to the motor, such as low gain in the driver.
A progressive failure may be just on the edge of supplying enough current to keep it
rotating, but not enough for startup torque. On Sat, 9 Dec 2017, allison via cctalk wrote:
Functions normally save for the motor does not always turn on command
but will if manually pushed. All other functions are normal. I have several Epson PX-8s and i used them.. They
work well with the
various wedges I have.
I also Have a PF-10 which is the portable 3.5" 40 track two side floppy.
The problem is it randomly does not turn the media unless I give it a
push to get it turning.
Things checked:
* Batteries, NEW fully charge (Both).
* internal Power supplies, current voltage and bridged with external
supplies does not help.
* media checked for binding, it does not.
When it turns it reads and writes correctly and at the correct speed.
It may do so without help for many tries then will stop required a
manual push.
At first glance I though there were motor bearing issues but have
verified
this is not so. If I force motor on and restrain it I has good torque
and no
dead spots. All signals in the motor control look good on the scope.
Any thoughts?
How does it detect the presence of a disk? and/or disk change?
9:27 a.m.
New subject: Epson PX-8 specifically TF-10 problem...
If it were a 5.25, I'd say it was the floppy sticking in the jacket.
Dwight
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of allison via cctalk
<cctalk at classiccmp.org>
Sent: Sunday, December 10, 2017 4:26:24 AM
To: Brent Hilpert via cctalk
Subject: Re: Epson PX-8 specifically TF-10 problem...
On 12/09/2017 09:14 PM, Brent Hilpert via cctalk wrote:
On 2017-Dec-09, at 6:06 PM, allison via cctalk wrote:
That was my thought and I checked, not the problem. I suspect that the
magnets in the rotor
have gotten really weak.
Allison
On 12/09/2017 07:52 PM, Fred Cisin via cctalk
wrote:
How about a problem
with the current supply to the motor, such as low gain in the driver.
A progressive failure may be just on the edge of supplying enough current to keep it
rotating, but not enough for startup torque. On Sat, 9 Dec 2017, allison via cctalk wrote:
Functions normally save for the motor does not always turn on command
but will if manually pushed. All other functions are normal. I have several Epson PX-8s and i used them.. They
work well with the
various wedges I have.
I also Have a PF-10 which is the portable 3.5" 40 track two side floppy.
The problem is it randomly does not turn the media unless I give it a
push to get it turning.
Things checked:
* Batteries, NEW fully charge (Both).
* internal Power supplies, current voltage and bridged with external
supplies does not help.
* media checked for binding, it does not.
When it turns it reads and writes correctly and at the correct speed.
It may do so without help for many tries then will stop required a
manual push.
At first glance I though there were motor bearing issues but have
verified
this is not so. If I force motor on and restrain it I has good torque
and no
dead spots. All signals in the motor control look good on the scope.
Any thoughts?
How does it detect the presence of a disk? and/or disk change?
1:26 a.m.
New subject: Epson PX-8 specifically TF-10 problem...
On Sun, Dec 10, 2017 at 2:06 AM, allison via cctalk
<cctalk at classiccmp.org> wrote:
Assuming it's the same as the one I worked on some years ago...
Functions normally save for the motor does not always turn on command
but will if manually pushed. All other functions are normal.
Assuming it's the same motor as the one I worked on :
What is the voltage on the collector of Q18 (== emitters of
Q15...Q17) when the motor should run but doesn't? If it's
close to the supply rail then the problem is in the motor or
commutation circuitry, if it is low then the problem is in the
speed control or the motor is not being told to run.
With the motor running, look at the waveforms on :
Collectors of Q15...Q17 (drives to the motor windings)
Pin 1,15,16 of IC13 (TA7745) (drives to those transistors)
Pins 2...7 of IC13 (outputs of the hall sensorts that detect
the motor position).
In each case the 3 (or 6) signals should look much the same,
if one is different or missing then the problem is in the motor
commutation circuit.
-tony
> How does it detect the presence of a disk?
and/or disk change?
It's a mechanical switch on the motor PCB. A similar switch detects
the write-protect hole.
Totally irrelevant to the matter at hand:
BTW, how close to "industry standard" is the interface to the drive
mechanism itself? Would it be practical to replace the mechanism
with one of the 80 track (and also 2 sided?) Epson drives? Either the
whole drive, if it is fairly "standard", or just the stepping
mechanism if there is another Epson drive similar enough?
No its an oddball. The read-wirite electronics are part of the
intelligent mainboard that communicates
with the pX-8 serially. The only board that is part of the drive is the
motor control.
2416
days inactive
2420
days old
8 comments
7 participants
participants (7)
-
allisonportable＠gmail.com -
ard.p850ug1＠gmail.com -
bhilpert＠shaw.ca -
cisin＠xenosoft.com -
dkelvey＠hotmail.com -
michael.99.thompson＠gmail.com -
v.slyngstad＠frontier.com