Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

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stephen_usher
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Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by stephen_usher »

Seeing as Exxos' TOS relocator board is out of stock and unlikely to be available for the foreseeable future it got me wondering.

To fit the TF536 into a STFM and close the case there requires to be a CPU relocator board, which would be of a reasonable size, so would have plenty of space for the TOS address mapping logic. It would also be large enough to also hold a 16 bit EPROM chip of some kind, possibly even one of the dualtos ones.

(a) How feasible would it be to combine all the requirements into the one board?
(b) What is the logic required for the address decoding?

Just thinking aloud.
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by PhilC »

@stephen_usher ive been toying with the idea of making a small board that sits on top of a TF536 and provides the tos decoding. Its an interesting idea with having both the decoder and dual tos rom on the relocator. Only problem I can see is that one size doesn't fit all but as long as its not a silly style board it should be possible.
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by stephen_usher »

Hmm.. some sort of shielded ribbon cable from the CPU location to the interface board? I guess timing and signal degradation may be the problem then. Probably not feasible actually.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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DoG
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by DoG »

Where is the TF536 been relocated to? Since the relocator board is building a few mm too. To get the keyboard and lid on I mean. Easiest would be to put the PSU outside the case and put it there.
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by PhilC »

@DoG I've done a real simple one that puts it left and back about 50mm, so hoping that will miss the shifter shield.

I think I'll move it further back and spin it round so that it clears everything instead though but obviously open to suggestions.

That and I liked @derkom's idea to keep both CPUs inside the case to switch between them.
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by stephen_usher »

I'll have to get the experimental machine down from the loft and take a look at the layout. There will be an old RAM expansion to deal with too.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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JezC
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by JezC »

PhilC wrote: Mon Sep 21, 2020 8:48 pm That and I liked @derkom's idea to keep both CPUs inside the case to switch between them.
I would love to have this capability on the H4 as well as the older machines!
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by PhilC »

@JezC its certainly a possibility on the H4, maybe there could be two interconnected boards in two of the DIL sockets that do the switch?
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by JezC »

@PhilC That's one option certainly...the other would be the decoder card with a PLCC 68k (relocated from the MoBo socket) plus the socket for the TF536 to plug into.

Either of these approaches might give a bit more clearance under the TF536 - it's sitting very close to the MFP/DMA etc. so I've got a piece of thin card underneath the TF board ATM...just in case!
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Re: Just wondering: TF536 CPU relocator+2.06 decode+ROM all on the one board?

Post by PhilC »

@JezC mine is in the top left socket with a decoder board underneath, no space needed. Might be worth trying there perhaps?
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