4 Jan
2011
4 Jan
'11
5:23 p.m.
I picked up an interesting bit of hardware on ebay. It's one of these
without components:
http://www.amiga-hardware.com/showhardware.cgi?HARDID=1360
Does anyone have a way of getting at a component list for this?
brian
4 Jan
4 Jan
6:59 p.m.
In article <AANLkTikv8B8XSBquZF2Yt89izaETQTk9iLab1=6_rKzL at mail.gmail.com>,
Brian Lanning <brianlanning at gmail.com> writes:
I picked up an interesting bit of hardware on ebay.
It's one of these
without components:
http://www.amiga-hardware.com/showhardware.cgi?HARDID=1360
Does anyone have a way of getting at a component list for this?
I would ask on Amiga forums for someone who already has one of these
to make you a parts list.
FWIW, on the terminator board I'm guessing that the upper left 7
components are pull-up resistor packs to bring bus lines high and the
capacitors are decoupling capacitors for some of the signal lines.
Power and ground, maybe?
The chips on the main board are another matter, but I would guess
either slot address decode logic or bus drivers.
Maybe you can infer what needs to go there by the tracing the metal
runs on the board and referring to a schematic for the Amiga bus.
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7:28 p.m.
In article <B5DCF3FC045C4B1190BE725BBD10F60C at portajara>,
"Alexandre Souza - Listas" <pu1bzz.listas at gmail.com> writes:
Probably address decode. This is a really simple board and shouldn't
defy reverse engineering.
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Does anyone
have a way of getting at a component list for this?
Bad news Brian, seems there are three programable ICs on the big
board...see the bottom (leftmost on the picture) chips, looks like PALs :(
8:23 p.m.
On Tue, Jan 4, 2011 at 9:15 PM, Alexandre Souza - Listas
<pu1bzz.listas at gmail.com> wrote:
How can you tell? It's practically impossible to read the numbers.
Does anyone
have a way of getting at a component list for this?
? Bad news Brian, seems there are three programable ICs on the big
board...see the bottom (leftmost on the picture) chips, looks like PALs :(
6 Jan
6 Jan
2:54 p.m.
On Tue, Jan 4, 2011 at 10:55 PM, Alexandre Souza - Listas
<pu1bzz.listas at gmail.com> wrote:
I talked to someone who used to be involved with bill's board. He
pointed me to this:
http://olson-ndt.com/AMIGA/BusExpander/
Looks like there's schematics, information about trace errors on the
board, and some experimental equations for the PALs, but apparently
the originals are lost.
brian
How can you
tell? ?It's practically impossible to read the numbers.
? The logo of the manufacturer :)
5:38 p.m.
In article <AANLkTimdYquuPUptUu0xZs5U1iTkUPkXDv36ONkxAEMy at mail.gmail.com>,
Brian Lanning <brianlanning at gmail.com> writes:
Looks like there's schematics, information about
trace errors on the
board, and some experimental equations for the PALs, but apparently
the originals are lost.
PALs are simple two-level programmable logic. It shouldn't be hard to
create a truth table from the real PALs by adapting them to a PROM
reader. From there you can recreate PAL equations from the truth
table.
--
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5:43 p.m.
On 1/6/11 8:38 PM, Richard wrote:
It's a bit tougher when they're registered and can maintain
(relatively) complex state, though. Many (most?) PALs are registered.
-Dave
--
Dave McGuire
Port Charlotte, FL
Looks like
there's schematics, information about trace errors on the
board, and some experimental equations for the PALs, but apparently
the originals are lost.
PALs are simple two-level programmable logic. It shouldn't be hard to
create a truth table from the real PALs by adapting them to a PROM
reader. From there you can recreate PAL equations from the truth
table. 
8:22 p.m.
On Thu, Jan 6, 2011 at 8:43 PM, Dave McGuire <mcguire at neurotica.com> wrote:
?It's a bit tougher when they're registered
and can maintain (relatively)
complex state, though. ?Many (most?) PALs are registered.
When I used to work with real MMI PALs in the 1980s, we used *lots* of
"H" and "L" parts with only about 5% "R" (Registered) parts
(10H8,
14L2...) Could have been a cost thing. Could have been a designer
prejudice thing.
GALs, though, are a different story, since AFAIK, for all intents and
purposes, all outputs are registered (but the flip-flop can be
bypassed if the logic terms don't "activate" it). I haven't fully
explored GAL complexity, but my understanding is that for the same
size of package, one GAL can assume the function of any of the PALs
its size (i.e., a 16V8 can be programmed as a drop-in replacement for
a 10H8 or 16L2 or 12R6, etc).
Then there's the security bit. I don't think we ever set it on ours,
but companies paranoid about knockoffs did.
-ethan
7 Jan
7 Jan
12:21 p.m.
size of package, one GAL can assume the function of
any of the PALs
its size (i.e., a 16V8 can be programmed as a drop-in replacement for
a 10H8 or 16L2 or 12R6, etc).
Almost, but not quite. The GAL cna replace _most_ of the PALs, but it
doesn't have XOR terms, so it won;'t replae thigns liek a 16X4. Yes, i
have seen those used.
Then there's the security bit. I don't think
we ever set it on ours,
but companies paranoid about knockoffs did.
A lot of companies, particularly in the early days relied on what one of
the 'Art of Electronics' books called 'Secrity though solder'. They
didn't blow the security fuise, but they soldered the PAL to the PCB. If
you were able to remove it without damage, you could get the equations.
But then there were HALs (Hard Array Logic), which were essentially mask
programmed PALs. Similar part numbers (a HAL10L8 is the mask-programemd
PAL10L8, etc. AFAIK there was no way to read the fuse map out of these
devices they were effective all secured.
-tony
1:51 p.m.
New subject: IBM 026 on EPAY
item no 190487994052
IBM 026 punch in Manassas, VA offered by a recycler outfit
$500 BIN or offer
s2
1:56 p.m.
New subject: IBM 026 on EPAY
On Fri, 7 Jan 2011, steve shumaker wrote:
item no 190487994052
IBM 026 punch in Manassas, VA offered by a recycler outfit
$500 BIN or offer
Yuck - major rust and corrosion. Much as I'd like to find one, it
looks like too much work.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
8 Jan
8 Jan
6:59 p.m.
It's a bit tougher when they're registered
and can maintain (relatively)
complex state, though. Many (most?) PALs are registered.
I still think it is easier to look at the circuit, understanding how it
works and recreating the equations...
(ha ha ha, I have a logic analyser, I can do anything up to 400MHz, la
la la, I'm the greatest hacker of the world, la la la) :oD
9 Jan
9 Jan
10:28 a.m.
It's a bit tougher when they're
registered and can maintain (relatively)
complex state, though. Many (most?) PALs are registered.
I still think it is easier to look at the circuit, understanding how it
works and recreating the equations... (ha ha ha, I have a logic analyser, I can do
anything up to 400MHz, la
la la, I'm the greatest hacker of the world, la la la) :oD
Good for you...
-tony
7 Jan
7 Jan
11:28 a.m.
PALs are simple two-level programmable logic. It
shouldn't be hard to
create a truth table from the real PALs by adapting them to a PROM
reader. From there you can recreate PAL equations from the truth
table.
The rpoblem comes when the PAL is not simple combinatorial logic, but
implements sequiential functions too.
There are 2 main ways this can happen. Firslty, there are registered PALs
(often with an 'R' in the part number) which hae intenral D-tpye
flip-flops. The D inputs come from the programmable logic, the Q outputs
are availabe on external pins _and are fed back to the logic internally_.
So you can make state machines, etc.
The second way is that some 'normal' PALs have feedback terms. That is
the outputs of the progamamble logic array not only goes ot output pins
but also back into the logic array. You can make SR flip-flops vry easily
this way.
Wth sequential logic, you can't just try all the inputs, record the
outputs nad reduce the logic equations...
Iunderstnd there are some early-vrsion PAL equations for this device
avaialble. Has anyone looked at them to see what htey do? Is it purely
combinatorial (e.g. address decoers), or are there sequential functions too?
-tony
4878
days inactive
4882
days old
15 comments
8 participants
participants (8)
-
ard＠p850ug1.demon.co.uk -
brianlanning＠gmail.com -
ethan.dicks＠gmail.com -
legalize＠xmission.com -
mcguire＠neurotica.com -
mloewen＠cpumagic.scol.pa.us -
pu1bzz.listas＠gmail.com -
shumaker＠att.net