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Author Topic: EPROM/Flash ROM/SRAM expansions (Read 56161 times)

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #60 on: 2014.February.06. 17:30:10 »
Okay, I fixed it easy,  now I have all the memory, but not working ExDOS. IF I put the ROM the EP checks the RAM and then goes to a black screen and freezes. Would I disconnect the extra pins to the 128k ROM?
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Vale, lo he solucionado fácilmente, pero EXDOS no funciona. Si coloco la ROM el EP hace el chequeo de Ram y después se va a una pantalla negra y se congela. Le desconecto los pins extra?

Offline Zozosoft

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #61 on: 2014.February.06. 18:18:22 »
Quote from: gflorez
Okay, I fixed it easy,  now I have all the memory, but not working ExDOS. IF I put the ROM the EP checks the RAM and then goes to a black screen and freezes. Would I disconnect the extra pins to the 128k ROM?
I think the problem are the EXDOS ROM now mirrored and four EXDOS ROMs make a conflict. I thinking what you can do easy...
« Last Edit: 2014.February.06. 18:35:28 by Zozosoft »

Offline Zozosoft

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #62 on: 2014.February.06. 18:54:04 »
Quote from: Zozosoft
I think the problem are the EXDOS ROM now mirrored and four EXDOS ROMs make a conflict.
No, if you use my quick test in the cartridge, it is handle the mirroring.

Another idea: for the modification do you cutted the VCC from the old sockets pin 28, and replaced with another signal?
After do this, do you recovered the WD1772 power line? Need to cut the IC 7 (original) Pin 28 to WD1772 Pin 15 line (this is at the bottom of PCB), and connect WD1772 Pin 15 to +5V.

If the EXDOS can't detect WD then it is frozen because waiting forever...

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #63 on: 2014.February.06. 20:00:14 »
Yes, the WD1772 is already powered, I've tested. On EPROM socket old pin 28, new 30, I've put line A17, in new 31 put WE and in new 29 put A14.

On SRAMS new 31 has A14, and in new 29 has WE.

May be I've interchanged two lines, and then the memory works the same, but I've tested and don't find the error.

Edit:Sorry not pin 27, it is 29
« Last Edit: 2014.February.06. 20:25:52 by gflorez »

Offline Zozosoft

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #64 on: 2014.February.06. 20:19:34 »
For the EPROM, later Flash ROM:
New 1 to A21 (currently don't used)
New 2 to A16
New 3 (Old 1) A15
New 29 (Old 27) A14
New 30 (Old 28) A17 (currently don't used)
New 31 WE (currently don't used)
New 32 +5V

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #65 on: 2014.February.06. 20:27:16 »
Mistake, where I say 27 is 29. Edited.

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #66 on: 2014.February.06. 20:42:40 »
Tomorrow more....

Offline Zozosoft

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #67 on: 2014.February.06. 21:21:45 »
Can you make photos of the modifications?
« Last Edit: 2014.February.06. 22:15:52 by szipucsu »

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #68 on: 2014.February.07. 10:40:42 »
To make the conversion easier I used two more sockets for SRAM, above of which are welded to the plate, so the socket you adapted for the Eprom is now one level below.

  Yesterday I extracted and inserted the chips about twenty times each, and one of them, when I didn't know why only worked half the SRAM, I realized I had displaced a pin the Eprom. 5vcc entering by WE...

Can I have fired the Eprom?



If so, the conversion could be correct and we only have to wait for the new Flash ROM.


Sorry for the bad quality of the pictures....



-------------------------


Para hacer la conversión mas facil utilicé otros dos zocalos para las SRAM, encima de los que están soldados a la placa, por lo que el zocalo que tú adaptaste para la Eprom queda un nivel por debajo.

 Ayer yo extraje e inserté los chips como unas veinte veces cada uno, cuando aun no sabía porqué solo funcionaba la mitad de la SRAM, y una de las veces me di cuenta de que había insertado la Eprom desplazada un pin hacia arriba. 5vcc entrando por WE...

¿Puedo haber quemado la Eprom?


Si así fuese, la conversión estaría correcta y solo nos quedaría esperar a tener la nueva Flash ROM.



Perdón por la mala calidad de las fotos....

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #69 on: 2014.February.07. 11:01:15 »
Without the EPROM:

Offline Zozosoft

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #70 on: 2014.February.07. 11:04:40 »
On the photos the EPROM inserted at wrong direction!!! Now i'm 99.999% sure it is dead :-(

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #71 on: 2014.February.07. 11:12:27 »
Oh no, I've killed it two times.....that's cruelty.

Don't let kids play with fire...

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #72 on: 2014.February.07. 11:21:44 »
It was dead before been "overkilled", it acts exactly the same: first a green screen then black....

Here we say, "dead king?, put new king", "a rey muerto rey puesto"....

Offline gflorez

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #73 on: 2014.February.08. 08:36:06 »
Reflexing about it, I just inserted the chip (backwards) for the photographs,  I extracted it immediately after, to do more testing to the wires and weldings.

Judge sorry, don`t condemn me,  I've only killed it once .....

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Pensándolo bien, justo inserté el chip (al revés) para hacer las fotografías, lo extraje inmediatamente para seguir comprobando los cables y soldaduras.

Perdóneme juez, no me condene, solo le maté una vez.....

Offline jltursan

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Re: EPROM/Flash ROM/SRAM expansions
« Reply #74 on: 2014.February.10. 20:38:59 »
Argh!, be careful with that poor EXDOS card! :shock:

Hope you can fix it simply replacing the damaged ICs ;-)

==========================================

¡Argh!, ¡ten cuidado con esa pobre controladora EXDOS! :shock:

Espero que puedas repararla reemplazando los CIs estropeados ;-)