SAMS for Tomy Tutor. What would it take?

[+retroclouds]

Considering how similar the TI-99/4a and Tomy Tutor are, what would it take to implement a SAMS version for the 9995?

As a starting point I'm thinking about the "new" sidecar SAMS  (32k replacement for TIPI)

 

[wierd_w]

Looking at the pinout of the expansion port...

 

Not much?

 

It has the address and data lines, MEMEN and CRUOUT/CRUCLK.

 

So..  Build one, and write some software to use it?

[+retroclouds]

6 hours ago, wierd_w said:

Looking at the pinout of the expansion port...

 

Not much?

 

It has the address and data lines, MEMEN and CRUOUT/CRUCLK.

 

So..  Build one, and write some software to use it?

 

I can write the software, but not build it. I'm an absolute hardware noob.

[Mobsie]

I can help with the Software and also will buy some then.

[+Ksarul]

One would need to determine the available memory spaces in the Tomy memory map and build out decoder circuitry to set the SAMS default memory spaces there. From there, there isn't all that much work to do, as you only need to be able to write to the registers on the 612 to set the SAMS memory spaces visible in the window to the portions of the default window you want them to be in.

 

Probably the first necessary experiment would be to build a basic memory expansion that uses the open spaces in the memory map--and I am pretty sure there has to be a switch in there somewhere that disables some or all of that memory space when a cartridge is inserted, as I think those spaces overlap. . .which may also reduce the utility of SAMS somewhat unless you copy the cart into the SAMS default space and then disable the cart port to use the copy in SAMS.

[+retroclouds]

On 4/11/2021 at 6:31 PM, Ksarul said:

One would need to determine the available memory spaces in the Tomy memory map and build out decoder circuitry to set the SAMS default memory spaces there. From there, there isn't all that much work to do, as you only need to be able to write to the registers on the 612 to set the SAMS memory spaces visible in the window to the portions of the default window you want them to be in.

 

Probably the first necessary experiment would be to build a basic memory expansion that uses the open spaces in the memory map--and I am pretty sure there has to be a switch in there somewhere that disables some or all of that memory space when a cartridge is inserted, as I think those spaces overlap. . .which may also reduce the utility of SAMS somewhat unless you copy the cart into the SAMS default space and then disable the cart port to use the copy in SAMS.

How would you disable the cartridge port, guess that has to be done in hardware right?

[wierd_w]

Just go for maximum geek, and use a cartridge slot adapter to put on a ribbon cable inside the cart slot, and route it to your SAMS back-porch. Allow the internal circuitry to disable the memory space (like it seems designed to do), and house the memory on the SAMS back-porch module.

 

The ribbon cable could be minimal-- just enough to get the circuitry inside the Tomy to free the memory areas, but still controlled by the SAMS card-- but if the memory areas are not addressable from the back porch (say, if address lines are abstracted with a multiplexer or something), then the ribbon could be used to route reads/writes also.  The two areas are conveniently close together, so it should be doable.  I am thinking something like a short (6in or less) 80conductor (40 pin) ATA100 cable, leveraging the extra grounding it would provide.