CURRENT PROTOTYPE STATUS (SEC 64MHz 68000)

[PhilC]

Will let you know when I get my hands on one. Aren't the CPU sockets the other way round? So should clear it?

Looks like it will fit because the major over hang is toward the prom chips. The issue looks like the fast rom card will conflict. We can make that work.

It's got on board Rom and Flash, so no more fast rom board required

[PaulJ]

Looks like it will fit because the major over hang is toward the prom chips. The issue looks like the fast rom card will conflict. We can make that work.

It's got on board Rom and Flash, so no more fast rom board required

Initially exxos wan't going to put the rom on but just a decode line out to the fast rom board. I haven't been watching that close so its nice he added the rom on.

[PaulJ]

Mega has the 1.5 in a socket so it will be quick swap. One question though, will the mega still need the 16 mhz clock cleanup board or is that handled on the booster also?

[exxos]

Initially exxos wan't going to put the rom on but just a decode line out to the fast rom board. I haven't been watching that close so its nice he added the rom on.

I think you are confusing this SEC booster with the V2.2. booster... The V2.2 booster needs a external ROM board now..

[PhilC]

That is a good question. I can see there is an oscillator on the board but wouldn't be surprised if we would still need the buffer board so it plays nicely.
Is all the Ram, Rom and Flash run at the same speed as the CPU Exxos?

[PaulJ]

Could be, I see an 68000 dip foot print it works for me. I'll take a 2.2,2.5,2.7,3,1,9.2... what ever you put on your site as long as it plugs into a 64 pin dip...

[exxos]

I can see there is an oscillator on the board but wouldn't be surprised if we would still need the buffer board so it plays nicely.

The SEC booster wouldn't need the MEGA ST buffer board.

Is all the Ram, Rom and Flash run at the same speed as the CPU Exxos?

Yes, for arguments sake, all at 50MHz.

[exxos]

OK so I labeled stuff up..

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As said before, eventually the PLCC ROM will go, but not during these prototype testing phases (plus no software to program the flash so one reason the PLCC remains there).

The flash is 45ns, ROM 55ns, So the likely maximum speed is 50MHz. As tested before, the CPU maxed out at 58MHz anyway.

It is a "stand alone" board so nothing else is needed to make it work. BUT if fitting on a MEGA ST/STF/M it will need the 10K SILs changing to 2.2k. We already have 2.2K on the STF remake (or 4.7K is fine there also).

Ultimately this booster will be integrated on the STF remake board, but that is a long long way away. For the next MB revision, it will have a DIP 68000 CPU socket to plug this booster into the MB.

Longer ahead, the fast-ram won't be needed, the whole 14MB ST-RAM area will be "fast-ram" but that is long long way in the future.

[exxos]

Got some tidying to do, but "layer 3" the connection from the SRAM/ROM data/address bus is routed now..

Need to find some easy PLD IO pins next to route to the SRAM CE lines..

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[PhilC]

Hi Exxos,

Quick question, will the on board ram of the STFM or Mega need to be disabled to use this board? Or will it just add an extra 8mb of fast ram?

My STFM is only 512k and didn't want to spend lots of time upgrading it if the Ram is ultimately not going to be used. (It's a spare machine that I've been fixing, waiting patiently for the SEC booster to be bought to life.)