New hardware revision?

[simon]

Well, it needs more than just to replace the CPU. If I would go with a full 68000 I will have a 16 bit databus. Then I would need a second Eprom* and the 16-to-8 bit buffer doesn't make sense anymore. Thus all in all it entails a slew of changes ending in completely reworking the PCB layout. I like the idea though but not without help. But eh you could get off from your couch and participate.

Simon

[Edit] * And a 16 bit width RAM. Probably no 30pin SIMM but 72pin SIMM[Edit]

[Zbigniew]

No, let's just start with something real, we can explore; "talk is cheap".

Actually I've found an interesting discussion which suggests to me, that 65816 could be a better fit even than a 68000.
But if selecting from more modern designs - I'm still voting for ARM.

[e2k001]

Well, it needs more than just to replace the CPU. If I would go with a full 68000 I will have a 16 bit databus. Then I would need a second Eprom* and the 16-to-8 bit buffer doesn't make sense anymore.

That's not really much more work.

Thus all in all it entails a slew of changes ending in completely reworking the PCB layout. I like the idea though but not without help. But eh you could get off from your couch and participate.

I actually never checked, but how did you make your design? Which tools did you use?

Simon
[Edit] * And a 16 bit width RAM. Probably no 30pin SIMM but 72pin SIMM[Edit]

You could get away with making part of the design 3v3, so some thing will be easier. And actually on a wish list,
some connector with buffered signals for add-ons?

[e2k001]

No, let's just start with something real, we can explore; "talk is cheap".

Actually I've found an interesting discussion which suggests to me, that 65816 could be a better fit even than a 68000.
But if selecting from more modern designs - I'm still voting for ARM.

Why would a 6502 be a better choice?

And please no ARM. In German, ARM and ARMselig sounds to close

But seriously, there is no way to compete in price and performance with all the BlackBones, Arduinos, and whatevers.
Than you have to discuss every transistor on the board with people, who just like to watch movies on a SBC

[simon]

I use the gEDA tools. These aren't that comfortable like commercial tools, but free of charge. If I keep in mind that it took me about a year (mainly because of other life tasks not because it is so much work) to get rev 2 into a produceable state I doubt that there will be a CPU upgrade without help of others. Thus my proposal is to go with the rev 2 at first. As we found out, the PCB isn't that expensive anymore. If you like to help, feel free to start the design upon my rev 2 design files. I don't mind to build a rev 3. Quite the contrary. I appreciate help.

Well, I have to leave to London know. You'll find the rev 2 design files in the rev 2 review thread.

Happy New Year!

Simon

Ps: I agree not to use ARM. At least not for Kiwi. But if you demand, we'll open this forum for other designs beside Kiwi.

[Zbigniew]

Why would a 6502 be a better choice?

Actually 65C816S, not 6502. Why it (possibly) could be even better than 68k... did you read the thread?

And please no ARM. In German, ARM and ARMselig sounds to close

Well, there's nothing wrong with that; ARM processor - being RISC - has "ARMer Befehlssatz". And this is one of its conveniences.

Ps: I agree not to use ARM. At least not for Kiwi. But if you demand, we'll open this forum for other designs beside Kiwi.

Really a pity - but 68k cannot be considered as "bad choice" anyway, therefore let's start with the present design, to see at last, how is it doing.

[Chris]

I plan on making a 68000 daughter board once my PCB arrives, I'm thinking it will plug into the 68008 position (not fitting a PLCC socket but some type of pin header) and the 16bit buffer locations. Obviously there will be issues such as tweaks to the VHDL to remove the 16bit handling, flying lead for the ATA interface. I'll also put a 72pin simm on the daughter board but the existing FPGA could still provide the ras/cas and mux signals.

[Chris]

Happy New Year and sorry for the double post, Simon are the Gerber files available so I can get an idea of how much space I will have to play with to build a daughter card?

Thanks

Chris

[simon]

Chris,

I've uploaded the gerber files to the internal forum. Could you check if your prefered manufacturer accepts these?

Simon

[Chris]

Chris,

I've uploaded the gerber files to the internal forum. Could you check if your prefered manufacturer accepts these?

Simon

Thanks Simon,

My copy of GC-Prevue opens these fine. I just wanted to see where I could attach a daughter card containing a 68000 and a 72pin simm and get exact positions for connection points to the Kiwi Board. I wasn't planning on getting a board made, I'm quite happy to wait for you to order

Regards

Chris