[Jul/31/96]

PISCES - A conversion for Galaxian.
-----------------------------------

The bad(ish) news is that this Galaxians board isn't a Midway one as the original Midway piggyback board seems to have been incoroprated into the main circuit board, with an extra LS138 added, and then a "new" larger piggyback board has been added. I think I've managed to sort it out...

VIDEO MODS
----------

2532 in location L1 with pin 18 lifted.
2532 in location J1 with pin 18 lifted.

J1 (2532) pin 18 -> L1 (2532) pin 18 -> M9 (74259) pin 6
(this seems to make COIN LOCKOUT into a bank select pin. This "non-Midway" board did not implement the COIN LOCKOUT)


CPU RAM MODS
------------

2114 piggybacked onto P7 with pin 8 lifted.
2114 piggybacked onto N7 with pin 8 lifted.

Additional 74LS139 bolted onto one of the chips but taking only power and ground from it. Desiganted AUX.

P7 (2114) upper pin 8 -> N7 (2114) upper pin 8 -> AUX (LS139) pin 5
AUX (LS139) pin 1 -> GND
AUX (LS139) pin 2 -> D7 (LS367) pin 13
AUX (LS139) pin 3 -> N2 (LS08) lifted pin 6
AUX (LS139) pin 4 -> N7 (2114) lower pin 8

All other AUX pins n/c.

(NOTE: Sean says that this extra RAM on my board is not required for Pisces).


CPU ROM MODS
------------

6 EPROMS in total, all TMS2516. Unpopulated space available for two more EPROMS and another TTL chip.

Additional LS138 added with designation C2.

EPROMS designated A1, A2, B2, C1, D1, E2.

(piggy) C2 (LS138) pin 1 -> (main) D7 (LS367) pin 3
(piggy) C2 (LS138) pin 2 -> (main) D7 (LS367) pin 5
(piggy) C2 (LS138) pins 3,4,5 -> GND
(piggy) C2 (LS138) pin 6 -> VCC

(piggy) B1 (main H1) pin 20 -> A1 (2516) pin 20 -> A2 (2516) pin 20 -> B2 (2516) pin 20 -> C1 (2516) pin 20
(piggy) E1 (main L1) pin 20 -> D1 (2516) pin 20 -> E2 (2516) pin 20
(piggy) A1 (2516) pin 18 -> (piggy) C2 (LS138) pin 15
(piggy) C1 (2516) pin 18 -> (piggy) C2 (LS138) pin 12
(piggy) D1 (2516) pin 18 -> (piggy) C2 (LS138) pin 15
(piggy) A2 (2516) pin 18 -> (piggy) C2 (LS138) pin 14
(piggy) B2 (2516) pin 18 -> (piggy) C2 (LS138) pin 13
(piggy) E2 (2516) pin 18 -> (piggy) C2 (LS138) pin 14

I presume it should map to a contiguous block. I have omited the EPROM address and data connections as they are connected as usual.



[05/12/96]

        PISCES   CHIP PLACEMENT

CHIP #  POSITION  TYPE
----------------------
PIS1     1A       2716   DAUGHTER BOARD
PIS2     2A        "       "
PIS3     2B        "       "
PIS4     1C        "       "
PIS5     1D        "       "
PIS6     2E        "       "
PIS      KL       2732   MAIN BOARD
PIS      HJ       2732     "



[Mar/16/2002]

This is the set of roms from a Subelectro Pisces board

G09,G10,G11 and G12 are graphics roms (2716)
P1,P2,P3,P4 and P5 are program roms (2716)
COLOUR.BIN is an 82S123

Standard Galaxian PCB with additional wire for graphics bank select


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[Jan/31/97]

This is an unkown game from 1981 by Irem. It was a conversion applied to a
pirate Galaxians board and appears similar to Pisces (both in game play and
conversion).

2K files were MB8516 (read as 2716)
32 byte prom was a MB7051 (read as an 82S123)

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