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Parker Bros card with different banks scheme? A2600


cetics

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I borrowed this card to try to fix it. (always with black screen). I remade all welds and tracks, tested the circuits with my logic circuit tester (TOP3000) and they were all shown to be good. But the sign keeps giving black screen.

I checked eprom 27128 (which came without a protective sticker) and read its contents (in the attached file) Analyzing the hex files it seemed to be two games (popeye and montezuma). But through my file analyzer realize that the files were different from the roms downloaded from the net for the same games (few bytes were different). The games copied from eprom (and divided into 2) did not work on the stella emulator even though choosing the parker bros bank. It seemed to me that the files were corrupted by the exposure of the eprom. I recorded a new eprom with ROMs (Parker bros 8k) from the internet but the card still doesn't work. Is this a different card? or is it a parker bros with original layout and am i missing something here?
* The card came with loose wires and as they were connected to the highest address of the eprom I thought they were for the game exchange key, but it had no effect when placing it.

Could anyone check the position of the diodes? I received the plate I don't know if anyone tried to repair the plate before ... the two diodes came with the mark down.

Following is a file with the ROMs and more pictures of the circuits removed.

 

Board circuits:
74LS173 x3
74LS00 x1
Diodes x2
Ceramic capacitors x3
Resistors x3
Original Eprom: 27128 Intel

 

Thanks to everyone and thanks to "ODIN Games" for providing me with the test board.

inicial.jpg

Parker bros.zip

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  • 3 weeks later...
Congratulations, I liked the images and files of this cartridge.
Please What is the value of the Capacitors, take a picture with the clear values.

I'll give some tips

1- Connect the orange wire together with a 1K resistor and the other end on the GND or VCC.

2- Change the CIS 74ls173 and 74ls00, it may be damaged.

3- Clean the terminals with rubber.

I'll try to reverse engineer and create a copy to test your Bin file
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All capacitors are: (102).
I had connected the orange wire directly to the VCC (without result)
... then I connected directly to the GND (also without result).
I will try with the resistor.

I replaced the 74LS00 with a new one (with no result).
The 74ls133 I have no others to exchange.
But my eprom recorder tests circuits and shows everyone how good.


I also remade the welds and tracks and cleaned the contacts.
(no result yet).

Thank you for the tips.

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Just now, cetics said:

Todos os capacitores são: (102).
Eu tinha conectado o fio laranja diretamente ao VCC (sem resultado)
... então eu liguei diretamente ao GND (também sem resultado).
Vou tentar com o resistor.

Troquei o 74LS00 por um novo (sem resultado).
Os 74ls133 não tenho outros para trocar.
Mas meu gravador eprom testa circuitos e mostra todos como é bom.


Também refiz como vendido e como trilhas e limpei os contatos.
(nenhum resultado ainda).

Obrigado pelas dicas.

 

 

 

Try this:

1 - Pin 26 of the Eprom 27C128 put 1 resistor 1K connected GND or VCC

2 - Pin 6 CI 74ls00 must be at 0 Volts

3 - Test continuity between the terminals of the board with those of the CI. Note: Do you have a cartridge box with the cover? Your file is fine, it has been modified to work on that circuit on this board.

 

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Liguei o resistor, mas se efeito (nada no gnd ou no vcc) o
pino 6 do 74ls00 está conectado ao 22 do eprom.

Liguei o cartucho e durante a operação o pino 6 do 74ls00 sobe para 1 volt e permanece assim.
(ponta preta do multímetro em GND e ponta vermelha no pino 6 dos 74ls00.

 

I don't have a cartridge box, I received the card like that and with the wires loose.

 

res 1k.jpg

Edited by cetics
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Just now, cetics said:

Estou redesenhando o cartão. esse é o lado de trás (se eu não fiz nada de errado).
depois de terminar tudo eu vou subir os gerbers

REDESENHO BACK.jpg

 

Good evening. The drawing is getting very good, congratulations.

Please send the schematic files, I want to help with this project.

I found something strange.

CI 74ls00 pin 14, I believe it must be connected to the VCC.

The strangest thing is the eprom 27c128 Pin 26 is connected to the VCC, so the Bank 8K hangs Then Pin 12 should change the Bank of 8K, Montezumba or Popeye Please send the Top drawing and the Button of your plate.

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Attempts to connect Pin 2 of Eprom 27C128, connect the 1K resistor and at the other end connect GND There is a solder on the track connecting the pin 2 of the eprom 27c128, together with the 74ls173 Pin 4 removes this solder, preventing the VCC from connecting pin 2 of the eprom. 8K banK exchange can happen

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Are you referring to this weld shown on the arrow? This solder did not exist previously. I cut the trail for a test, and then I fixed it.


Pin 14 of the 74ls00 is connected to the VCC. In my drawing it didn't show because I was still completing it.


From the information I have, the 27128 would have 16K. Pin 26 would be the highest address (A13), and its change between VCC and GND would change the two halves of eprom (for the two 8k games).


Parker bros sistens should divide the rom into 8 slices of 1K according to this document:(http://www94.pair.com/jsoper/2600_pb_bs.html)

 

As for pin 12, it appears to me as D2.

 

SOLDA.jpg

Edited by cetics
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I'm out of materials to manufacture a board at home, but as soon as possible, I'll order one from JLCPCB.

Thanks for drawing. In my drawing I tried to represent it as close as possible to the original in order to get the best scheme. But you improved the scheme, congratulations.

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  • 7 months later...
  • 8 months later...

Desculpe a demora em responder.
 

Eu não tenho o esquema. Eu fui olhando para a placa e desenhando. Fiz diretamente o desenho no Diptrace, sem fazer o esquema antes.

Sorry for the delay in responding.

I don't have the schema. I was looking at the board and drawing. I made the drawing directly in Diptrace, without doing the schematic first.

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  • 6 months later...
On 7/15/2021 at 4:11 PM, cetics said:

Desculpe a demora em responder.
 

Eu não tenho o esquema. Eu fui olhando para a placa e desenhando. Fiz diretamente o desenho no Diptrace, sem fazer o esquema antes.

Sorry for the delay in responding.

I don't have the schema. I was looking at the board and drawing. I made the drawing directly in Diptrace, without doing the schematic first.

I need your drawings but not in gerber format, I want to print the 2 sides of the circuit separately to make my own pcb of this board.

Edited by Pilot99
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  • 2 months later...
On 3/22/2020 at 5:43 AM, cetics said:

The games copied from eprom (and divided into 2) did not work on the stella emulator even though choosing the parker bros bank. It seemed to me that the files were corrupted by the exposure of the eprom. I recorded a new eprom with ROMs (Parker bros 8k) from the internet but the card still doesn't work. Is this a different card? or is it a parker bros with original layout and am i missing something here?

Late to the party, sorry.

 

It seems that this cart uses different (yet unknown to Stella) bankswitching hotspots. Parker uses hotspots in the ROM address range at 0xffe0..fff8. Here the addresses are outside the ROM address range (e.g. 0x03b2, 0x03d1, 0x03e3) and do not map 1:1 to the original hotspots (e.g. 0xffe3 -> 0x03e3,  0xffe9 -> 0x03d1, 0xfff2 -> 0x03b2).

 

The mapping is:

0xFFE0..7 -> 0x03E0..7 (1st 1K slice)
0xFFE8..F -> 0x03D0..7 (2nd 1K slice)
0xFFF0..7 -> 0x03B0..7 (3rd 1K slice)

Another cool find from Brazil! :thumbsup:

 

@alex_79 What do you think about this one?

Edited by Thomas Jentzsch
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I totally missed this thread.

 

I had a look, using the pcb files in post #19 and this is how I understand it:

There are 3 74LS173 ICs to act as registers for the bank that must appear in one of the 3 lower 1k segments in cart space:

 

Segment #0 ($f000-$f3ff):

Address mask:     $1397
hotspots:     $380-$387    (to select bank 0-7)

 

Segment #1 ($f400-$f7ff):
Address mask:     $13a7
hotspots:     $380-$387    

 

Segment #3 ($f800-$fbff):
Address mask:     $13c7
hotspots:     $380-$387    

 

Segment #4 ($fc00-$ffff):
always points to bank 7 (because of the 3 pullup resistors on EPROM addresses A10,A11,A12)


The address accessed before the hotpsot must be in cart space (A12 high). That's because the inverted A12 is used as the clock input for the 74LS173, and the clock must be on a positive transition for the IC to load a new value. So a "LDA $3e[0..7]" executed from zero page ram will NOT change the bank in segment #0!

 

Also note that the hotspots addresses overlap, so it is possible to cause the same bank to appear in multiple segments by accessing a single address!

A4=0 loads the bank number for segment #0

A5=0 loads the bank number for segment #1

A6=0 loads the bank number for segment #2

If more than one of those address bits are 0, then the specified bank will be set for each associated segment.

 

 

Edited by alex_79
corrected IC part number
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