9 Jan 2019

Sega 315-5298 GAL22V10 alternative (System 16B)



While working on the System 16B multi I soon discovered some romboards (171-5704/171-5521/171-5797) contained a PLS153 chip noted 315-5298 used for tiles banking. Unfortunately I own only one System 16B game (Shinobi) and it runs on 171-5358 romboard which is the simplest one and lacks the PLS153 chip (not needed as early games had less tiles). Fortunately collector lapsus sent me one for dumping (side note: PLS153 can't be read protected/locked).

Using MAME's tool jedutil I dumped equations (jedutil -view source.bin device, where device = PLS153):

Inputs:
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19
Outputs:
9 (Combinatorial, Output feedback output, Active high)
11 (Combinatorial, Output feedback output, Active high)
12 (Combinatorial, Output feedback output, Active low)
13 (Combinatorial, Output feedback output, Active low)
14 (Combinatorial, Output feedback output, Active high)
15 (Combinatorial, Output feedback output, Active high)
16 (Combinatorial, Output feedback output, Active high)
17 (Combinatorial, Output feedback output, Active high)
18 (Combinatorial, Output feedback output, Active high)
19 (Combinatorial, Output feedback output, Active high)
Equations:
o9 = /i4 & o14 +
     i4 & o17
o9.oe = vcc
o11 = /i4 & o15 +
      i4 & o18
o11.oe = vcc
/o12 = /i4 & o16 +
       i4 & o19
o12.oe = vcc
/o13 = /i4 & /o16 +
       i4 & /o19
o13.oe = vcc
o14 = i5 & o14 +
      i7 & o14 +
      i6 & o14 +
      i1 & /i5 & /i6 & /i7
o14.oe = vcc
o15 = i5 & o15 +
      i7 & o15 +
      i6 & o15 +
      i2 & /i5 & /i6 & /i7
o15.oe = vcc
o16 = i5 & o16 +
      i7 & o16 +
      i6 & o16 +
      i3 & /i5 & /i6 & /i7
o16.oe = vcc
o17 = /i5 & o17 +
      i7 & o17 +
      i6 & o17 +
      i1 & i5 & /i6 & /i7
o17.oe = vcc
o18 = /i5 & o18 +
      i7 & o18 +
      i6 & o18 +
      i2 & i5 & /i6 & /i7
o18.oe = vcc
o19 = /i5 & o19 +
      i7 & o19 +
      i6 & o19 +
      i3 & i5 & /i6 & /i7
o19.oe = vcc

Then I converted them for a GAL22V10 (thanks to lapsus again for probing the PLS153 pinout/signal names).
GAL16V8 is unfortunately 1 output short and I have no GAL18V10 in my parts stock (was it ever used on any arcade PCB?).

Name U153_V1;
Partno PAL_CE;
Revision 01;
Date 01/05/2018;
Designer Apocalypse;
Company None;
Location None;
Assembly None;
Device g22v10;
/****************************************************************/
/* */
/* General File Comments */
/* */
/****************************************************************/
/*
* Inputs: define inputs in this section
*/
Pin 1 = db0;
Pin 2 = db1;
Pin 3 = db2;
Pin 4 = ga15;
Pin 5 = ad1;
Pin 6 = rom2;
Pin 7 = lwr;
/*
* Outputs: define outputs as active HI levels in this section
*/
Pin 23 = o19;
Pin 22 = o18;
Pin 21 = o17;
Pin 20 = o16;
Pin 19 = o15;
Pin 18 = o14;
Pin 17 = ce1;
Pin 16 = ce2;
Pin 15 = a16;
Pin 14 = a15;
/*
* Logic: logic equations in this section
*/
a15 = !ga15 & o14 # ga15 & o17;
a16 = !ga15 & o15 # ga15 & o18;
!ce2 = !ga15 & o16 # ga15 & o19;
!ce1 = !ga15 & !o16 # ga15 & !o19;
o14 = o14 & (ad1 # rom2 # lwr) # db0 & !ad1 & !rom2 & !lwr;
o15 = o15 & (ad1 # rom2 # lwr) # db1 & !ad1 & !rom2 & !lwr;
o16 = o16 & (ad1 # rom2 # lwr) # db2 & !ad1 & !rom2 & !lwr;
o17 = o17 & (!ad1 # rom2 # lwr) # db0 & ad1 & !rom2 & !lwr;
o18 = o18 & (!ad1 # rom2 # lwr) # db1 & ad1 & !rom2 & !lwr;
o19 = o19 & (!ad1 # rom2 # lwr) # db2 & ad1 & !rom2 & !lwr;

It made perfect sense to me (data bits are latched to create higher address lines).
Testing on my custom multi romboard revealed it worked pefectly fine.
lapsus confirmed it to be working on OG hardware too by using a small adapter to reroute a couple of signals as the PLS153 is DIP20 and GAL22V10 is DIP24:
- ground by connecting pin 12 (GAL22V10) to 10 (PLS153 socket)
- generated a15 line from pin 14 (GAL22V10) to pin 9 (PLS153 socket)
GAL22V10 pin 1 has to be aligned to PLS153 socket pin 1, pins 11/12/13/14 stick out:

PLS153 GAL22V10
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 14
10 12
11 15
12 16
13 17
14 18
15 19
16 20
17 21
18 22
19 23
20 24

6 comments:

  1. http://www.jammarcade.net/new-pal-dumps-added/

    https://postimg.cc/JtBnDVFf

    http://www.jammarcade.net/files/pals/System16-315-5298.jed

    ReplyDelete
    Replies
    1. Hi Caius, glad to see you still read me.
      I didn't know you dumped that chip already.
      Anyway I was more interested in showing the method and providing the source files so people can see equations and adapt them to other devices if they like.

      Delete
    2. By the way I will also make an article about the security chip found on Sega's System 24 romboards as I have successfully reversed it.
      Done it before?

      Delete
    3. If you tell me the marking/label of this System24 security chip I can check but if it's not a PLD probably we never faced it.

      Delete
    4. Marking varies from game to game, it's an Altera EPM5032 PLD (DIP28):
      - Bonanza Bros 317-0156
      - Dynamic Country Club 317-0177
      - Quiz Mekuromeku Story 317-0205
      - Tokoro San no MahMahjan 317-0200
      - Quiz Rouka Ni Tattenasai 317-0191
      - Tokoro San no MahMahjan 2 317-0220
      - Quiz Ghost Hunter 317-0226

      Delete
  2. OK, no problem.It was only to inform you that this PLD was already dumped and reversed in a GAL18V10 (so with no need of adapter).As always hat off to your great work! ;)

    ReplyDelete