- FREEDOM OF SPEECH -

or lets finish some of the multi- sega kit.......................

by Fred Konopaska
aka juice28

         I don't know about most of the individuals that installed Clay's Multi-Sega kit, but I like it for the most part. After playing for about 10 minutes though I realized something had to be done about the speech board at the least. Since I had a Star Trek speech board to begin with the other games (Zektor and Space Fury) would ramble Star Trek garbage that made no sense. Although my son and I got a kick out if it for about 2 minutes........

I wanted to try to finish this kit a little more then it was and not have to swap roms to hear the right speech on different games. So begins the multi-sega kit speech board hack ;)

        What this hack will do:

         This hack will make your speech board automatically load the correct code for the games that use the speech PCB. These include Star Trek, Space  Fury and Zektor. NOTE because the sound board is not reset between games it may occasionally hang when switching games but reseting to the menu and trying again clears it up. I am working on a simple fix to reset the sound board indivual of the CPU board between games to clear this up.

         What this hack will NOT do:

         This hack does not address the issue of replacing or adding the different sound PCB's such as the Universal Sound board, Elim/Zec sound board and so on. I'll leave this for another hack/upgrade doc.

NOTE- If you do this hack and mess up your speech pcb, game or yourself don't blame me. If you can't handle this hack then please don't do it.

         Parts needed for this hack:

27C010 Eprom (or equiv 128k*8 eprom)
27C32  Eprom (or equiv 4k*8 eprom)
Combined rom images (or the ability to combine them)
Wire, ability to soldier and read a schematic.

Remove u7,u6,u5,u4 and u3 from you sega speech pcb.

MAKE SURE YOUR SEGA SPEECH BOARD IS JUMPERED FOR 2732 EPROMS IN THE U3, U4, U5 AND U6 POSITIONS. U7 MUST BE JUMPERED FOR 2716.

Refer to the schematics to be sure. If your pcb has a 2716 in U7 and the rest are 2732's then your okay.

Lets dig into it.

Looking at the doc's that came with the Multi Sega, Clay has added the ability to bank switch sound boards and speech boards. This is a great plus as without this latch byte this hack would be impossible without redesign of the whole kit and code.....He actually has two 1 byte latches but we are only concerned with latch 1.

Info from Multi-Sega installation manual:

If we disregard the top bits D5-D7 and just focus on the 3 lower bits we can derive this.

These are the bit patterns we need to enable the different roms for each of the games that use speech. At first glance it looks unfriendly but if you think about it there is a way around it. You could either use some crazy logic to decode these four different 3 bit patterns then bank switch the eprom with that or you can do it the easy way (ilbiet wasteful). Since eproms are cheap I am taking the easy way.

Star Trek and Zektor use the same code in the U7 eprom. Space Fury uses different code in U7. U7 is a 27C16 in both games so if we burn a 27C32 with Star Trek in the bottom half and Space Fury in the top half and use the A11 pin we can bank switch with D1 of latch1.

So go ahead and burn a 27C32 with the combined Star Trek and Space Fury U7 Roms or my file. Bend pin 21 (A11) up on the 27C32 and plug it into the U7 socket on your speech board. Run pin 21 (A11 of 27C32)  to D1 of latch1 on the multi sega.

Now combine and burn a 27C010 eprom according to the table below or use the code I combined.

Bend up pins 1, 2, 3, 4, 22, 24, 28, 29, 30, 31 and 32 on the 27C010. Place the 27c1001 into the U5 socket. Line the bottom of the 27C010 up with the bottom of the socket so the top stick over the socket.

1, 32 and 31 go to +5V someplace on the speech board.
22 and 24 together to pin 8 of u14 on the speech board.
4 to pin 35 of u14.
28 to pin 36 of u14.
29 to D0 latch1 on the multi-kit.
3 to D1 latch1 on the multi-kit.
2 to D2 latch1 on the multi-kit.

Put your pcb back in and give it a try.

Thats ii for now. I'll compile the roms and go through these while installing this hack to be sure all is correct. If you find errors please let me know. If you damage your pcbs using this hack you're on your own. If you think of an easy way to reset just the sound board between games give me an email.

Fred
AKA JUICE28
Arcadexpo@mchsi.com