27 Oct
2005
27 Oct
'05
6:28 a.m.
The FPGA/Xilinx swearing around here reminds me...
Many years ago (OK, decades, actually a good chunk of a
century now) the tools for doing embedded software development from
the manufacturers were:
1. Distributed as source code
2. Widely portable
3. Well-documented in terms of file formats
Examples are the Intel 8008 PL/M compiler they released in Fortran
and the original PALASM (Monolithic Memories?) in Fortran.
(IIRC the PALASM source appeared in printed form in one of
the manuals).
Even for commercial tools, the three "good things" enumerated
above were often true. The reason for this
openness was because user's didn't all
have identical development platforms, often they had access
to a timesharing system or a departmental minicomputer that
they used for cross-compilation etc.
Since then of course the tools have become MSDOS/Windows-only,
distributed only as binaries, and sometimes the file formats/
programming process are trade secrets (often reverse-engineered
by those using them!) I can see why this happened: supposedly
everybody had a PC-clone running Microsoft software, so you
could just give away or sell binaries instead of source code.
Of course, freeware embedded tools (e.g. GNU and others) today reflect
a backlash against the Windows-ization of embedded development
tools.
A similar thing has happened to SPICE (most users are not
using the open-source Berkeley code but instead proprietary
versions which lock them in to a specific vendor and that vendor's
component models). And there's
the backlash to this in the open-source community (SPICE3
with ngspice/gEDA and some GUI's layered on top of it.)
But in my experience, outside the hobbyist community the
freeware embedded tools don't have much traction. I'd be glad to
be proven wrong! Actually I do know of a couple of
small commercial projects that used gcc for StrongARM and
have heard of a couple that use gcc for MSP430.
I myself use gputils (GNU PIC utilities) and gpsim occasionally
and am occasionally forced to plunge into hell with commercial
embedded development tools (which mostly suck) under
Windows.
OK, that's my pontification for this morning.
Tim.
27 Oct
27 Oct
8:40 a.m.
Tim Shoppa wrote:
But in my experience, outside the hobbyist community
the
freeware embedded tools don't have much traction. I'd be glad to
be proven wrong! Actually I do know of a couple of
small commercial projects that used gcc for StrongARM and
have heard of a couple that use gcc for MSP430.
Just spend some time and look, how many of the "commercial" vendors
are actually selling just front-end (GUI !) to tools from the GNU Chain.
This is at least true for a lot of the 32-bit developement packages.
And, even the big players are selling you those for big bucks.
I myself use gputils (GNU PIC utilities) and gpsim
occasionally
and am occasionally forced to plunge into hell with commercial
embedded development tools (which mostly suck) under
Windows.
Yes, and then you notice again, how easy it actually was, to make your
compiles with make, it was portable, and easy to understand what is
happening behind the scripts.
PFUI !
;-)
9:29 a.m.
Tim Shoppa wrote:
The FPGA/Xilinx swearing around here reminds me...
Many years ago (OK, decades, actually a good chunk of a
century now) the tools for doing embedded software development from
the manufacturers were:
1. Distributed as source code
2. Widely portable
3. Well-documented in terms of file formats
Examples are the Intel 8008 PL/M compiler they released in Fortran
and the original PALASM (Monolithic Memories?) in Fortran.
But then they changed Fortran compilers. $#!%
You can still get the source, just you can't compile on new machines easy.
9:56 a.m.
New subject: IBM 5155 Power supply schematics or info
I'm repairing an IBM 5155 with defective power supply. I've try some
components replacement (electrolitc capacitors) with no results. The
rectified main voltage is present, but it never start up.
Anyone know if there are schematics of this power supply available on the
net ?
Any experencies with this power supply ?
Thanks
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
1:36 p.m.
New subject: IBM 5155 Power supply schematics or info
I'm repairing an IBM 5155 with defective power supply. I've try some
components replacement (electrolitc capacitors) with no results. The
rectified main voltage is present, but it never start up.
I hav ereverse-engineered this unit (there is no official schematic in
any of the manuals).
Anyone know if there are schematics of this power
supply available on the
net ?
Alas I have no scanner, so as yet there are no schematics in eelctronic
form. But I will see if something can be done.
Any experencies with this power supply ?
I've never had to repair one, but from what I remember it is a fairly
conventional design.
-tony
2:19 p.m.
New subject: IBM 5155 Power supply schematics or info
I hav ereverse-engineered this unit (there is no
official schematic in
any of the manuals).
Great! I have plan to do the same, in nobody has already done :)
Alas I have no scanner, so as yet there are no
schematics in eelctronic
form. But I will see if something can be done.
Thanks, thanks and more thanks !
I've never had to repair one, but from what I
remember it is a fairly
conventional design.
In the past I've repaired two, but with very simple damage, one with the
output capacitors die and another with the auxiliary little transformer with
primary coil interrupted.
The circuit work around an old pwm controller, SG3524 of SGS Thomson.
Thanks
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
3:48 p.m.
New subject: IBM 5155 Power supply schematics or info
I hav ereverse-engineered this unit (there is no
official schematic in
any of the manuals).
Great! I have plan to do the same, in nobody has already done :) Alas I have no scanner, so as yet there are no
schematics in eelctronic
form. But I will see if something can be done.
Thanks, thanks and more thanks ! I've never had to repair one, but from what I
remember it is a fairly
conventional design.
In the past I've repaired two, but with very simple damage, one with the
output capacitors die and another with the auxiliary little transformer with
primary coil interrupted.
The circuit work around an old pwm controller, SG3524 of SGS Thomson.
28 Oct
28 Oct
10:40 a.m.
New subject: IBM 5155 Power supply schematics or info
I traced out scheamtics of the PSUs in all my IBMs...
Great work ! Normally I trace out schematics only when I need to repaire its
and I cannot find any schematics on the net.
How quickly do you need this? I am wondering if
handing a copy to a
friend at an HPCC meeting in a couple of weeks time would be soon enough.
No problem for the time, it's a hobby (great but hobby) non work :)
Yes, and the control chip is on the 'output'
side of the PSU, the drive
to the bases of the chopper transistors is transformer-coupled. There are
3 little daughterboards in there.
I have take a look at the circuit. It' similar to some off line converters
and other supplies, with control on the secondary side and not in the "live"
part of the switch mode.
One is an inrush limiter and contains a
relay that shorts out a power resistor once the smoothing capacitors have
charged.
This work, I've tested. The 4 ohm resistor is shorted correctly by the relay
Another contains the overcurrent protection circuit,
and, IIRC,
a 12V regulator. The last contains the overvoltage protection circuit
(the chips on that board are LM339 quad comparators).
I'm thinking about some protection circuit, because the switching try to
startup, for a time less then half second, and then stop. Now I can try to
check il any protection become active during startup.
The SG3524 il correctly powered and try to fire up the switching
transistors, via the pulse transformer, but only for a short time.
Thanks
Alberto.
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
27 Oct
27 Oct
6:44 p.m.
New subject: IBM 5155 Power supply schematics or info
I traced out scheamtics of the PSUs in all my
IBMs...
Great work ! Normally I trace out schematics only when I need to repaire its
and I cannot find any schematics on the net. How quickly do you need this? I am wondering if
handing a copy to a
friend at an HPCC meeting in a couple of weeks time would be soon enough.
No problem for the time, it's a hobby (great but hobby) non work :) Yes, and the control chip is on the
'output' side of the PSU, the drive
to the bases of the chopper transistors is transformer-coupled. There are
3 little daughterboards in there.
I have take a look at the circuit. It' similar to some off line converters
and other supplies, with control on the secondary side and not in the "live"
part of the switch mode. One is an inrush limiter and contains a
relay that shorts out a power resistor once the smoothing capacitors have
charged.
This work, I've tested. The 4 ohm resistor is shorted correctly by the relay Another contains the overcurrent protection
circuit, and, IIRC,
a 12V regulator. The last contains the overvoltage protection circuit
(the chips on that board are LM339 quad comparators).
I'm thinking about some protection circuit, because the switching try to
startup, for a time less then half second, and then stop. Now I can try to check il any protection become active during startup.
The SG3524 il correctly powered and try to fire up the switching
transistors, via the pulse transformer, but only for a short time.
Do you get any voltage appearing on any of the outputs? Even for that
half-second?
-tony
6 Nov
6 Nov
8:43 a.m.
New subject: IBM 5155 Power supply schematics or info
There are 2 protection circuits. One is a current
sensor, there's a
current transformer in series with the chopper transformer primary
winding. The other is a set of voltage sensors.
Whatever you do, don't disable any of the trips. If there really is
something wrong, the results would be spectacular!.
Do you get any voltage appearing on any of the outputs? Even for that
half-second?
Today I have dedicated another time to this power supply :)
The SG3524 is correctly powered, it receive about 8V to its power pin and
give 5V on the reference output.
The sawtooth signal is present and good, like the oscillator output.
The inhibit pin is not active.
When I switch on the power supply, voltages on the outputs make a little
pulse, but of less then one second.
I'm workingo on :)
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
3:03 p.m.
New subject: IBM 5155 Power supply schematics or info
There are 2 protection circuits. One is a current
sensor, there's a
current transformer in series with the chopper transformer primary
winding. The other is a set of voltage sensors.
Whatever you do, don't disable any of the trips. If there really is
something wrong, the results would be spectacular!.
Do you get any voltage appearing on any of the outputs? Even for that
half-second?
Today I have dedicated another time to this power supply :)
The SG3524 is correctly powered, it receive about 8V to its power pin and
give 5V on the reference output.
The sawtooth signal is present and good, like the oscillator output.
The inhibit pin is not active.
7 Nov
7 Nov
7:06 a.m.
New subject: IBM 5155 Power supply schematics or info
2) It's shut down. The shutdown pin is driven from
the SCR CR11 on the
1144-01E PCB. That takes inputs from the current sense circuit and the
overvoltage shutdown. Since you say that the shutdown pin is not asserted
(do check this at the 'other' side of R11, 6k8), I think this is not the
problem weeither.
I was in error, the 3524 is shutdowned (lessical correct? :))
After a short time (during this outputs are available) the signal on R11
goes high, blocking 3524
Now I try to understand if is current overload or voltage protection circuit
that become active.
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
4:47 p.m.
New subject: IBM 5155 Power supply schematics or info
2) It's shut down. The shutdown pin is driven
from the SCR CR11 on the
1144-01E PCB. That takes inputs from the current sense circuit and the
overvoltage shutdown. Since you say that the shutdown pin is not asserted
(do check this at the 'other' side of R11, 6k8), I think this is not the
problem weeither.
I was in error, the 3524 is shutdowned (lessical correct? :))
After a short time (during this outputs are available) the signal on R11
goes high, blocking 3524
Now I try to understand if is current overload or voltage protection circuit
that become active.
8 Nov
8 Nov
12:57 p.m.
New subject: IBM 5155 Power supply schematics or info
I think I would check C3001, in case it's shutting
the PSU down before
it's properly started. Then look at the collectors of Q3002 to see if the
thing is detecting an overvoltage.
The under voltage protection is always active :(
When power is applied, the collector of Q3001 goes high (about 4.5V)
immediatly, after about 0.5 seconds, the SCR is fired and the power supply
enter in protection mode.
During the short time of outputs presents, I have check the value (with
scope, multimeter in not enough fast) but they are of the correct value (+5,
+12, -5, -12) but I ignore the tolerance of the under voltage protection.
Maybe IC3001 or IC3002 defective ?
Thanks a lot !
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
1:53 p.m.
New subject: IBM 5155 Power supply schematics or info
I think I would check C3001, in case it's
shutting the PSU down before
it's properly started. Then look at the collectors of Q3002 to see if the
thing is detecting an overvoltage.
The under voltage protection is always active :( When power is applied, the collector of Q3001 goes
high (about 4.5V)
Well, it shoud be until the PSU gets going :-).
immediatly, after about 0.5 seconds, the SCR is fired
and the power supply
enter in protection mode.
I presume that delay is that 47uF capacitor charging up. So that's probably
not defective.
During the short time of outputs presents, I have
check the value (with
scope, multimeter in not enough fast) but they are of the correct value (+5,
+12, -5, -12) but I ignore the tolerance of the under voltage protection.
Maybe IC3001 or IC3002 defective ?
Or the transistor is open-circuit?
Still, you're now down to one simple-ish stage that presumably you can
debug.
Incidentally, I should get a copy of the schematics to Dave at the
weekend for scanning.
-tony
2:29 p.m.
New subject: IBM 5155 Power supply schematics or info
Well, it shoud be until the PSU gets going :-).
Right
I presume that delay is that 47uF capacitor charging
up. So
that's probably
not defective.
Yes, is this delay. I have change the capacitor with a new one, to be sure
of this delay ... but with no effect
Maybe IC3001
or IC3002 defective ?
Or the transistor is open-circuit? Still, you're now down to one simple-ish stage
that presumably you can
debug.
Yes , the only question is : what is the tolerance of these protections ?
Incidentally, I should get a copy of the schematics to
Dave at the
weekend for scanning.
They are good ! very good.
I'm writing a little page with information on how to repaire this power
supply, and can complete.
Thanks
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
3:12 p.m.
New subject: IBM 5155 Power supply schematics or info
Maybe IC3001 or IC3002 defective ?
Or the transistor is open-circuit? Still, you're now down to one simple-ish
stage that presumably you can
debug.
Yes , the only question is : what is the tolerance of these protections ?
9 Nov
9 Nov
3:41 p.m.
New subject: IBM 5155 Power supply schematics or info
I think what I might do next is get a spare
comparactor chip of the same
type (LM339) and connect the power and ground pins to the power and
ground pins of the chip on the board (I am not _sure_ they both have the
same power and ground connections, check this!). Then link the inputs --
right way round -- to each of the 4 comparators in the undervoltage
circuit in turn. Put a suitable pull-up resistor (to the comparator power
connection on the output).
I have found the voltage under threshold isolating one by one the output of
the four comparator (desoldering the pin) and there is two voltage out of
range : +12V is 11V and -12V is 10V. In fact the two comparator of the two
voltage, if connected, shut down the power supply.
I have test the power supply without the two comparator output connected,
and it work , with load ... but I have tested it for a short time, no more
than 20-30 sec, I'm afraid of dangerous effect :)
Tomorrow I try to undestand how these voltages are low.
Alberto.
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
5:01 p.m.
New subject: IBM 5155 Power supply schematics or info
I have found the voltage under threshold isolating one
by one the output of
the four comparator (desoldering the pin) and there is two voltage out of
range : +12V is 11V and -12V is 10V. In fact the two comparator of the two
voltage, if connected, shut down the power supply.
Do you have anough load on the _+5V_ supply? Remember, these supplies
regulate the 5V output (that's the one that's fed back to the error
amplifier on the 3524 chip), and the other outputs follow along. If you
don't give the 5V supply enough load, the supply doesn't have to 'work
very hard', and the other outputs tend to be low.
Alos check the output capacitors. A dried up one will cause all sorts of
problems.
-tony
11 Nov
11 Nov
4:03 p.m.
New subject: IBM 5155 Power supply schematics or info
Do you have anough load on the _+5V_ supply? Remember,
these supplies
regulate the 5V output (that's the one that's fed back to the error
amplifier on the 3524 chip), and the other outputs follow along. If you
don't give the 5V supply enough load, the supply doesn't have to 'work
very hard', and the other outputs tend to be low.
I have loaded all the outputs : on +5 the load is about 3A.
I have try to increase the load, but no effect.
Alos check the output capacitors. A dried up one will
cause all sorts of
problems.
All the electrolitic capatitors were replaced, was the first thing I do.
Without undervoltage protection for +12 and -12 the power supply work, with
load, I've tested it.
But isn't a solution bypass the protection :((( I don't want .
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
15 Nov
15 Nov
1:34 p.m.
New subject: IBM 5155 Power supply schematics or info
Alos check the output capacitors. A dried up one will
cause all sorts of
problems.
All the capacitors of this power supply were replaced, all semiconductor
tested, various control done ....
but the problem remain the same : the outputs are a few low , sufficent to
trigger under voltage protection.
With under voltage protection disabled, it work without problem with a hard
load.
Now: it's correct to adjust the trimmer R18 to obtain correct outputs ?
I'm not able to understand what i changed in this supply, maybe the sign of
the time :)
Alberto.
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
10:44 a.m.
New subject: IBM 5155 Power supply schematics or info
Alos check the output capacitors. A dried up one
will cause all sorts of
problems.
All the capacitors of this power supply were replaced, all semiconductor
tested, various control done ....
but the problem remain the same : the outputs are a few low , sufficent to
trigger under voltage protection.
With under voltage protection disabled, it work without problem with a hard
load.
Now: it's correct to adjust the trimmer R18 to obtain correct outputs ?
16 Nov
16 Nov
3:43 p.m.
New subject: IBM 5155 Power supply schematics or info
I think that would be OK. While it's a bad idea to
randomly make
adjustments, you are not doing that. You have a fairly clear idea of
what's going on, and what that trimmer adjusts.
As soon as I touched the trimmer, I discover the problem !! The cursor was
instable !!
The outputs voltages changes only posing the screwdriver on the trimmer.
Now, with a new trimmer (a good Beckman) the voltage in full adjustable in
the range.
I have tested this power supply with various load and the regulation on 5V
and 12V is good.
I'm writing a web page with all your notes, my experience, photo, schematic
and data sheets.
Thanks a lot !
Alberto
------------------------------------------------------
Alberto Rubinelli Mail : alberto at a2sistemi.it
A2 SISTEMI Web : www.a2sistemi.it
Via Costantino Perazzi 22 Tel 0321 640149
28100 NOVARA (NO) - ITALY Fax 0321 391769
Il mio museo di vecchi computers/My old computers museum
http://www.retrocomputing.net
ICQ : 49872318 Skype : albertorubinelli
------------------------------------------------------
4:21 p.m.
New subject: IBM 5155 Power supply schematics or info
On 11/17/2005 at 12:43 AM Alberto Rubinelli - A2 Sistemi wrote:
As soon as I touched the trimmer, I discover the
problem !! The cursor was
instable !!
Congratulations!
One of life's hard-learned lessons: On old equipment, pots, switches,
sockets and connectors are not your friends.
Cheers,
Chuck
17 Nov
17 Nov
4:34 a.m.
New subject: IBM 5155 Power supply schematics or info
On Wed, 2005-11-16 at 16:21 -0800, Chuck Guzis wrote:
On 11/17/2005 at 12:43 AM Alberto Rubinelli - A2
Sistemi wrote:
pots normally seem to be OK though *until you touch them*, as the wiper
still has good contact until it's moved onto a corroded spot. Personally
I've found it unusual to find one that's failed without even being
touched.
(sockets and connectors seem much more prone to vibration or heat-
related movement, and of course switches always live with some of their
contacts exposed to corrosion anyway)
cheers
Jules
As soon as I touched the trimmer, I discover the
problem !! The cursor was
instable !!
Congratulations!
One of life's hard-learned lessons: On old equipment, pots, switches,
sockets and connectors are not your friends. 
16 Nov
16 Nov
11:51 p.m.
New subject: IBM 5155 Power supply schematics or info
At 12:34 PM 11/17/05 +0000, you wrote:
On Wed, 2005-11-16 at 16:21 -0800, Chuck Guzis wrote:
The monitors in the Intel MDS systems frequently have the exact same
problem. Move them slightly and the problem disappears!
Joe
On 11/17/2005 at 12:43 AM Alberto Rubinelli - A2
Sistemi wrote:
pots normally seem to be OK though *until you touch them*, as the wiper
still has good contact until it's moved onto a corroded spot. Personally
I've found it unusual to find one that's failed without even being
touched. As soon as I touched the trimmer, I discover the
problem !! The cursor was
instable !!
Congratulations!
One of life's hard-learned lessons: On old equipment, pots, switches,
sockets and connectors are not your friends.
(sockets and connectors seem much more prone to vibration or heat-
related movement, and of course switches always live with some of their
contacts exposed to corrosion anyway)
cheers
Jules
17 Nov
17 Nov
12:41 p.m.
New subject: How exactly do PAL chips get programmed?
As some of you might recall I was looking for drivers for my Tokamac II FX
PDS card on my mac IIfx. Well I found the drivers from the original company
founder. I read in Macworld (and had it confirmed from the company contact)
that you need a PAL chip on the IIfx reprogrammed (or replaced?) because
Apple screwed up BUS mastering on the IIfx and nobody caught on at the time
because those types of cards were rare.
Well I have found another person who has the same card AND the PAL chip
needed on his unit but is having other problems getting his setup to work.
What I want to know is are PAL chips somewhat like eprons in getting
programmed or is there some other process involved? Does anybody know of a
way to get a pre programmed chip dumped so it can be duplicated or do you
need the original chip (or code) to do this? If I can be duplicated does
anybody here have equipment to do it?
I just want to get this card running being thats its rare and a cool upgrade
for a cool machine.
Does anybody here have any experience with a IIfx running a Tokamac II FX
upgrade processor?
1:45 p.m.
New subject: How exactly do PAL chips get programmed?
"Teo Zenios" wrote:
What I want to know is are PAL chips somewhat like eprons in getting
programmed or is there some other process involved?
depends. old original pals were fuse-link and hence OTP (one time
programmable). At some point "GALS" came along which could be erased
and reprogrammed (they are more like eeproms in their technology as I
recall).
In most cased you could replace a PAL with a GAL, as long as the speed
of the part was correct.
What's the part? if it's something like a 16L8 or a 22V10 then you
should have no problem.
It is possible to 'program' a pal such that it can't be read. If your
pal has had this done you are out of luck. If it hasn't you should have
not problem reading the contents.
Does anybody here have any experience with a IIfx
running a Tokamac II FX
upgrade processor?
I actually had one and did some things with it but it was such a long time
ago that I have no recollection, sorry. I do remember it ran a demo very
quickly (I think it did fractals on the screen).
I don't remember having to replace a pal, however. And I used it on a
IIfx.
-brad
2:20 p.m.
New subject: How exactly do PAL chips get programmed?
In most cased you could replace a PAL with a GAL, as
long as the speed
of the part was correct.
The main exception being the PALs with XOR terms (16X4, etc IIRC).
What's the part? if it's something like a 16L8 or a 22V10 then you
should have no problem.
It is possible to 'program' a pal such that it can't be read. If your
For the record, this applies to GALs too. I _think_ you can still 'bulk
erase' and re-use GAL that's been protected, but you can't read out the
programming pattern.
-tony
2:13 p.m.
New subject: How exactly do PAL chips get programmed?
As some of you might recall I was looking for drivers for my Tokamac II FX
PDS card on my mac IIfx. Well I found the drivers from the original company
founder. I read in Macworld (and had it confirmed from the company contact)
that you need a PAL chip on the IIfx reprogrammed (or replaced?) because
Apple screwed up BUS mastering on the IIfx and nobody caught on at the time
because those types of cards were rare.
Well I have found another person who has the same card AND the PAL chip
needed on his unit but is having other problems getting his setup to work.
What I want to know is are PAL chips somewhat like eprons in getting
programmed or is there some other process involved? Does anybody know of a
Well, physically, a true PAL (as opposed to a GAL or similar) is
programmed like a fusible link PROM. There are little 'fuses' on the chip
that you burn out when you program it.
However, there is one important difference between a programmable logic
device (PAL, GAL, CPLD, etc) and a memory (PROM. EPROM, Flash, etc). And
that is that when you read a memory, you are effectively reading out the
programmed pattern directly. When you use a logic device you are not
Therefore, PALs (etc) have a 'programming mode'. You get to it by,
normally, 'overvoltaging' one of the pins. In this mode, the other pins
on the chip select a particular fuse, and enable you to program or read
it. The exact method varies from device to device and manufacturer to
manufacturer, and often was not available without an NDA (although the
methods for the first PALs were published in the data sheets).
This, in general is the only way to read out the contects -- the
programming -- of the chip. In nromal mode, you can attempt to solve it
as an unknown logic circuit, but rememebr there might be feedback terms
or internal D-types (depending on the PAL) which will give sequential as
opposed to combinatiorial behaviour.
And there is some bad news. There is a 'security fuse' in most, if not
all, PALs. If that has been programmed, there is no (official) way to
read out the fusr map. You can only use the device in normal, not
programming, mode. It's a sort of copy-protection.
If you know the device type and manufactuer and have a programmer that
supposts that _exactly_, it won't hurt to try to read it out. But don't
be suprised if you get a file of all 0's or all 1's.
-tony
3 p.m.
New subject: How exactly do PAL chips get programmed?
So if I have the original code and know what chip it needs to be programmed
on I might be in luck, otherwise there is little hope?
Are PAL's or GALs expensive to get? Do people here have access to
programmers?
----- Original Message -----
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
To: <cctalk at classiccmp.org>
Sent: Thursday, November 17, 2005 5:13 PM
Subject: Re: How exactly do PAL chips get programmed?
>
> As some of you might recall I was looking for drivers for my Tokamac II
FX
> PDS card on my mac IIfx. Well I found the drivers
from the original
company
> founder. I read in Macworld (and had it confirmed
from the company
contact)
> that you need a PAL chip on the IIfx reprogrammed
(or replaced?) because
> Apple screwed up BUS mastering on the IIfx and nobody caught on at the
time
> because those types of cards were rare.
>
> Well I have found another person who has the same card AND the PAL chip
> needed on his unit but is having other problems getting his setup to
work.
>
> What I want to know is are PAL chips somewhat like eprons in getting
> programmed or is there some other process involved? Does anybody know of
a
Well, physically, a true PAL (as opposed to a GAL or similar) is
programmed like a fusible link PROM. There are little 'fuses' on the chip
that you burn out when you program it.
However, there is one important difference between a programmable logic
device (PAL, GAL, CPLD, etc) and a memory (PROM. EPROM, Flash, etc). And
that is that when you read a memory, you are effectively reading out the
programmed pattern directly. When you use a logic device you are not
Therefore, PALs (etc) have a 'programming mode'. You get to it by,
normally, 'overvoltaging' one of the pins. In this mode, the other pins
on the chip select a particular fuse, and enable you to program or read
it. The exact method varies from device to device and manufacturer to
manufacturer, and often was not available without an NDA (although the
methods for the first PALs were published in the data sheets).
This, in general is the only way to read out the contects -- the
programming -- of the chip. In nromal mode, you can attempt to solve it
as an unknown logic circuit, but rememebr there might be feedback terms
or internal D-types (depending on the PAL) which will give sequential as
opposed to combinatiorial behaviour.
And there is some bad news. There is a 'security fuse' in most, if not
all, PALs. If that has been programmed, there is no (official) way to
read out the fusr map. You can only use the device in normal, not
programming, mode. It's a sort of copy-protection.
If you know the device type and manufactuer and have a programmer that
supposts that _exactly_, it won't hurt to try to read it out. But don't
be suprised if you get a file of all 0's or all 1's.
-tony
3:14 p.m.
New subject: How exactly do PAL chips get programmed?
Rumor has it that Teo Zenios may have mentioned these words:
So if I have the original code and know what chip it
needs to be programmed
on I might be in luck, otherwise there is little hope?
Are PAL's or GALs expensive to get? Do people here have access to
programmers?
I have a programmer that can do older PALs and/or GALS -- not enough brains
to actually use it, tho.[1]
Older PALs/GALs/PEELs can be had pretty cheaply at www.bgmicro.com (It's a
US company, dunno what's available worldwide, tho they might ship
worldwide... you'd have to ask them) - maybe someday I'll actually be able
to figure out how to program some of those critters.
Hope this helps,
Roger "Merch" Merchberger
[1] I do know how to use my programmer for EPROMs, but I've never
programmed a PAL/GAL before.
--
Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers
_??_ zmerch at 30below.com
(?||?) If at first you don't succeed, nuclear warhead
_)(_ disarmament should *not* be your first career choice.
18 Nov
18 Nov
7:41 a.m.
New subject: How exactly do PAL chips get programmed?
Roger Merchberger wrote:
Rumor has it that Teo Zenios may have mentioned these
words:
They do ship worldwide, payable via credit card, but be aware that you
might have additional costs at your local customs. Interestingly, this
happened to me only once in four cases...
Holger
So if I have the original code and know what chip
it needs to be
programmed
on I might be in luck, otherwise there is little hope?
Are PAL's or GALs expensive to get? Do people here have access to
programmers?
I have a programmer that can do older PALs and/or GALS -- not enough
brains to actually use it, tho.[1]
Older PALs/GALs/PEELs can be had pretty cheaply at www.bgmicro.com
(It's a US company, dunno what's available worldwide, tho they might
ship worldwide... you'd have to ask them) - maybe someday I'll
actually be able to figure out how to program some of those critters.
17 Nov
17 Nov
3:25 p.m.
New subject: How exactly do PAL chips get programmed?
Teo Zenios wrote:
So if I have the original code and know what chip it
needs to be programmed
on I might be in luck, otherwise there is little hope?
Are PAL's or GALs expensive to get? Do people here have access to
programmers?
<excellent replies snipped>
If you have a chip which you doubt is functional, it may still read out
it's fuse map.
The fuse map of say a 22L10 or such may be perfectly readable even if
the device
is not playing in the circuit. One thing that went bad on them was the
capability to
fully drive the loads in circuit to ttl valid regions. IIRC this would
be < .7 for low,
or > 2.2 for high. (for the sake of argument). When you pull the part
and put it in
a programmer, the loading is much more friendly, and the programmer may well
pull a copy of the fuse map unless the security fuse(s) are blown as
mentioned
by tony D.
For historys sake, the PAL's were programmed originally with a tool
called PALASM,
and later by lots of other tools. The fact that the security fuse could
be blown
meant that you had to have a way to determine if your device was
functional. This
was supplied in a proper environment by supplying a "model" which would flip
the lines according to function of the device and test it, after the
device was
programmed, to show that it was good.
Most engineers I ever worked with, and in the organizations I saw, few
things were
ever done but to save the PALASM source, (or whatever source) and the
binary
fusemap. If the engineer ever bothered to use the model and simulation
features,
and specify that, I never saw it. They usually would blow a pal, test
it in the
circuit, and when it worked, save the source and ship the fusemap out as
the only
thing to manufacture by.
Anyway to connect back up, what is malfunctioning, and why do you think the
pal's are bad? I didnt see a reason why that is suspected, or how you could
have found that out. I must assume you have a schematic to have figured
that
out.
Jim
3:33 p.m.
New subject: How exactly do PAL chips get programmed?
So if I have the original code and know what chip it needs to be programmed
on I might be in luck, otherwise there is little hope?
If you have the original, working, chip, it's worth sticking it into a
programmer that supports that chip and manufacturer and trying to read
it.
Some manufactuerers did not copy-protect their PALs. For example, all the
PALs in the VAX 11/730 CPU are readable (for all they're the key to the
design). All PALs in every PERQ I've seen (including the AGW3300) are
readable. All PALs in the Torch XXX -- apart from those on the (3rd
party?) 68020 kludgeboard -- are readable. But then again, most PALs on
clone ISA boards are protected.
If the original chip is a HAL, you are out of luck. HAL == Hard Array
Logic, it's a mask-programmed equivalent to a PAL. I've never found one
that can be read out, I suspect the circuitry simply isn't there.
-tony
5:49 p.m.
New subject: How exactly do PAL chips get programmed?
Tony Duell wrote:
If you know the device type and manufactuer and have a
programmer that
supposts that _exactly_, it won't hurt to try to read it out.
Presumably there are all sorts of 'standard' formats for storing read-out PAL
information, so:
1) What's the most sensible format to use, and
2) Is it possible for a PAL to fail reading in such a way that the data you
get out is junk - but not *obviously* junk to the user? (if I go around
backing PALs up I'd like to know for sure that the backups are good - but
obviously testing them at backup time by writing a new device for every single
one isn't much of a solution! :)
cheers
Jules
18 Nov
18 Nov
3:20 a.m.
New subject: How exactly do PAL chips get programmed?
Jules Richardson wrote:
Tony Duell wrote:
1) What's the most sensible format to use, and
jedec files. it's a standard.
2) Is it possible for a PAL to fail reading in such a
way that the data you
get out is junk - but not *obviously* junk to the user? (if I go around
backing PALs up I'd like to know for sure that the backups are good - but
you'll know. I think it will read all ones.
And it's possible to back out some crude verilog automatically for
smaller pals. I think Icarus verilog has a tool to do this. I recall
doing it for a simple 16L8.
-brad
6:24 p.m.
New subject: How exactly do PAL chips get programmed?
Presumably there are all sorts of 'standard'
formats for storing read-out PAL
information, so:
1) What's the most sensible format to use, and
The most standard, which should be supported by any PAL programmer and/or
design software, is called 'Jedec'.
2) Is it possible for a PAL to fail reading in such a way that the data you
get out is junk - but not *obviously* junk to the user? (if I go around
Alas yes. A chip can fail in all sorts of 'interesting' ways.
backing PALs up I'd like to know for sure that the
backups are good - but
obviously testing them at backup time by writing a new device for every single
one isn't much of a solution! :)
The best way I've found is to turn the jedec file back into the equations
(there used to be a free (binary-only) MS-DOS program for this provided
by National Semiconductor which covered most PALs and GALs of the time, I
think it was called JED2EQN.EXE) and see if the equations make sense.
Obviously if you get terms with both an input and its inverse ANDed in,
you start to get suspicious. If you have a scheamtic of the device the
PAL comes out of, you could see if the equations made sense for the
signals that go into the PAL
-tony
17 Nov
17 Nov
1:04 p.m.
New subject: IBM 5155 Power supply schematics or info
On Wed, 2005-11-16 at 16:21 -0800, Chuck Guzis wrote:
I can't beleive you've never had a VT220 with horizontal hold problems.
If you get that fault, the cure for 99% of them is to pull the cover,
twiddle the horizontal hold preset back and forth a few times, re-set it
to the original position, and give it a try. Most of the time you'll get
a good picture again.
The fact hat the 'right point' is still at the original setting seems to
prove it's not something else drifting in the terminal. It's bad contacts
at that preset.
-tony
On 11/17/2005 at 12:43 AM Alberto Rubinelli - A2
Sistemi wrote:
pots normally seem to be OK though *until you touch them*, as the wiper
still has good contact until it's moved onto a corroded spot. Personally
I've found it unusual to find one that's failed without even being
touched. As soon as I touched the trimmer, I discover the
problem !! The cursor was
instable !!
Congratulations!
One of life's hard-learned lessons: On old equipment, pots, switches,
sockets and connectors are not your friends.
16 Nov
16 Nov
4:48 p.m.
New subject: IBM 5155 Power supply schematics or info
I think that would be OK. While it's a bad
idea to randomly make
adjustments, you are not doing that. You have a fairly clear idea of
what's going on, and what that trimmer adjusts.
As soon as I touched the trimmer, I discover the problem !! The cursor was
instable !!
The outputs voltages changes only posing the screwdriver on the trimmer. Now, with a new trimmer (a good Beckman) the voltage
in full adjustable in
the range.
I have tested this power supply with various load and the regulation on 5V
and 12V is good.
I'm writing a web page with all your notes, my experience, photo, schematic
and data sheets.
All I ask is that my name remains somehow associated with the schematics.
-tony
6756
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39 comments
13 participants
participants (13)
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alberto＠a2sistemi.it -
ard＠p850ug1.demon.co.uk -
bfranchuk＠jetnet.ab.ca -
brad＠heeltoe.com -
cclist＠sydex.com -
emu＠ecubics.com -
holger.veit＠ais.fraunhofer.de -
julesrichardsonuk＠yahoo.co.uk -
jwstephens＠msm.umr.edu -
rigdonj＠cfl.rr.com -
teoz＠neo.rr.com -
tshoppa＠wmata.com -
zmerch＠30below.com