PAL16L8, PAL16R4, GAL16V8B replacement

[luiHS]

The same for U16. (GAL16V8 PDS ,JED, JDC).

Because of registered outputs, simple truth table can be inadequate.
So it have to be tested in oryginal board.

Regads
up8051 aka JarekC.DIY

Thank you I appreciate it.
Could you also do U15? It's the one missing for the three PALs on the board.

Regards

[up8051]

Yes.
But with U15 truth table is a problem:

Pin 18 - signal - /ROWDATA  in the truth table is always '1' but this line is used as clock for U27B.

Regards
up8051 aka JarekC.DIY

[luiHS]

Yes.
But with U15 truth table is a problem:

Pin 18 - signal - /ROWDATA  in the truth table is always '1' but this line is used as clock for U27B.

Regards
up8051 aka JarekC.DIY

Then the truth table is wrong ?


 

[pelule]

http://digsys.upc.es/ed/Programari/Programari.html
Windows 7 ? You need to test.

Expressso Source: https://wikivisually.com/wiki/Espresso_heuristic_logic_minimizer
/PeLuLe

[up8051]

Then the truth table is wrong ?

The same situation is with the BLANK signal.
The available truth table is insufficient to reverse engineering U15.


Regards,
up8051 aka JarekC.DIY

[luiHS]

.

Ok, thanks.
I will try with the ReGAL scripts, after capturing all the inputs / outputs with a Teensy programmed in C ++.

I have also seen this Chinese site, announce that they can apply reverse engineering to get the code of many chips, including PAL and GAL.

http://www.break-ic.com/index.asp

[up8051]

If you have oryginal chip U15 I think that Teensy and small program will be enough to reverse engineering.
You have to generate a little different set of test vectors (inputs) and read outputs.

Regards,
up8051 aka JarekC.DIY

[luiHS]

If you have oryginal chip U15 I think that Teensy and small program will be enough to reverse engineering.
You have to generate a little different set of test vectors (inputs) and read outputs.

Regards,
up8051 aka JarekC.DIY

Ok, thanks, I'll try to read the outputs  with all the input combinations to get the real truth table.

[luiHS]

If you have oryginal chip U15 I think that Teensy and small program will be enough to reverse engineering.
You have to generate a little different set of test vectors (inputs) and read outputs.

Regards,
up8051 aka JarekC.DIY

One more question, please.
Is there any way to know if a PAL / GAL is of registered outputs ?
If registered outputs, is it possible to apply reverse engineering with a truth table?

As soon as I assemble my board, I will verify it with the original GAL and with EEPLD ATF16v8 and its JEDEC for U26 and U16.  I understand then, that if the original GALs are registered outputs, your JEDEC files will not work. I'm right ?.

My last option, if all the reverse engineering fails, is to send the chips to "break-ic" chinese company, to get the code, although it is quite expensive, 350 USD per chip.

[up8051]

Hi,

My english is too bad to describe the whole process accurately
but shortly:

U15:
PAL16R4
pin1 - always Input, CLK function
Pin2-9 - always Input
Pin 11 - always Input, OE function
Pin 12,13,18,19 - Input or Combinatorial Output
Pin 14,15,16,17 - always Registered Output

The functions of pins 12,13,18,19 should be determined on the basis of the schematic.
In Dot Matrix controller this pins are Outputs (but can be feedback to logic matrix).

Three register cells are used as divider 2/4/8
Pin 15 (12 Mhz)
Pin 14 (N.C, but probably 6MHz)
Pin 17 (3MHz)
This signals are very likely  feedback to logic matrix, that is why it is necessary to expand number of input combinations.
You can treat the 3.6/12MHZ outputs as extra inputs.
You have test all input combinations for 8 combination of 3/6/12MHz outputs.

I can prepare list of required input combinations.

In GAL16V8 you can configure pins12..19 as input, combinatorial output or registered output, information about pin type is coded in JEDEC file.
GAL16V8 can replace PAL16L8, PAL16R4, PAL16R6,PAL16R8
JEDEC file for GAL16V8 is other ten for PAL16R4 even both do the same (different fuse maps).

We will do it without the help of chinese company

As a last resort, you can send me these chip to reverse engeenering.

Regards,
up8051 aka JarekC.DIY

[PCB.Wiz]

One more question, please.
Is there any way to know if a PAL / GAL is of registered outputs ?
If registered outputs, is it possible to apply reverse engineering with a truth table?

Yes, but as mentioned above, you need to expand the tests. You need to exercise the clock, and check output that change on clock, with possible conditional inputs.
You might also want to check for synthesised latch ?

Fortunately the 16V8 is simple, only one pin can be clock, and the circuit info guides what might be appearing on the pins to narrow down test possibilities.

[PCB.Wiz]

I have see that also TL866 chinese programmer can program some PAL/GAL, at least the last version, Plus II.

I contacted the TL866II Plus supplier and suggested they also add Test Vector support, and supplied an example JED file, that has appended vectors.
They can test Logic ICs so this should not be hard for them to add, and it would make this sort of task easier.

Meanwhile,  your custom teensy  can be used, and you could make that accept test vectors too... ?

[luiHS]

U15:
PAL16R4
pin1 - always Input, CLK function
Pin2-9 - always Input
Pin 11 - always Input, OE function
Pin 12,13,18,19 - Input or Combinatorial Output
Pin 14,15,16,17 - always Registered Output

The functions of pins 12,13,18,19 should be determined on the basis of the schematic.
In Dot Matrix controller this pins are Outputs (but can be feedback to logic matrix).

Three register cells are used as divider 2/4/8
Pin 15 (12 Mhz)
Pin 14 (N.C, but probably 6MHz)
Pin 17 (3MHz)
This signals are very likely  feedback to logic matrix, that is why it is necessary to expand number of input combinations.
You can treat the 3.6/12MHZ outputs as extra inputs.
You have test all input combinations for 8 combination of 3/6/12MHz outputs.

OK I understand now. Some pins are Output, and PAL also uses them internally to control other signals.
I see in the scheme, that in some pis puts I (input), other O (output), but in others it puts I/O (input/output) and Q (this can be an output of an internal flip/flop, and that also feedback to the PAL to control other signals?).

If so, they appear in the three PAL, pins I/O and Q that would be registered outputs with feedback to the PAL.

[luiHS]

One more question, please.
Is there any way to know if a PAL / GAL is of registered outputs ?
If registered outputs, is it possible to apply reverse engineering with a truth table?

Yes, but as mentioned above, you need to expand the tests. You need to exercise the clock, and check output that change on clock, with possible conditional inputs.
You might also want to check for synthesised latch ?

Fortunately the 16V8 is simple, only one pin can be clock, and the circuit info guides what might be appearing on the pins to narrow down test possibilities.

I understand, but it can be more complex if, as suggested by up8051, there are some outputs with feedback to the PAL, for example, outputs with 3Mhz, 12Mhz and others that in the scheme are indicated as I/O or Q.

[marcopolo]

For the TS68000 and HD6845SP, I contacted the Chinese, they have offered me very cheap prices, but I am not sure what they really offer me, I do not trust the Chinese sellers of vintage chips.

FYI, I have 16Mhz TS68000 DIP64 NOS available (Not chinese fakes or used, I bought the stock of an old retired electronic components reseller 12 years ago)
I also have a big stock of various PAL (20L8, 16R6, 20R6, 20R8, 20X10)

Marc

[luiHS]

For the TS68000 and HD6845SP, I contacted the Chinese, they have offered me very cheap prices, but I am not sure what they really offer me, I do not trust the Chinese sellers of vintage chips.

FYI, I have 16Mhz TS68000 DIP64 NOS available (Not chinese fakes or used, I bought the stock of an old retired electronic components reseller 12 years ago)
I also have a big stock of various PAL (20L8, 16R6, 20R6, 20R8, 20X10)

Marc

Hi.

Need PLCC68, DIP is not useful for my board. At any rate, tell me price and quantity available, may interest me if I modify my PCB to replace PLCC68 by DIP.

For PAL I prefer to use the current Atmel ATF16v8 to replace the old 16R4, 16L8 and GAL16v8.

[marcopolo]

I need to check my stock, but I think i have no more than 15-20 TS68000 16mhz

[tbrioux]

Hi all,
Sorry for digging this old thread, but does anyone finally have working jed files for U15 and U16 ?
I have a defect board and a good one, but I am not able to apply reverse engineering from myself...
Thank's
Thierry

[up8051]

Yes I did it.
I have jedec file for U15,U16 and U26

[tbrioux]

Hi,
up8051 told me he had files, but unfortunately for me no more response now since october 07...
Can someone else share files ?
Thank's
Thierry

[up8051]

Files are now available at Internet Pinball Database:
https://www.ipdb.org/machine.cgi?3593

Regards,
up8051 aka JarekC.DIY

[tbrioux]

Many thank's for that 
Thierry