I actually like the idea of a 68020 board, but I also think it would be cool to keep it alternative to the original 68000 board and not replace it completely. If the memory serves me correctly, 68020 are quite a bit more expensive and harder to get than the 68000 and i'd love to build the old board (tweaked or not) too.
After all, there is interest in the 4MB SRAM card even if we already have a 16MB board, for cost & ease of build reasons, isn't it? :-)
That said, if both are done I'd get 3x of each type.
--OK, OK there seems to be grown swell for a V2 of this board. We have three choices:-
We can tweak the layout, correcting little things like when the LED come on and what they represent – currently not really useful.
Also allow the board to function as a “slave of a slave” with the Z80 a master and a 80286 (or 80386) as a slave and a few other minor things.
We could probably squeeze in a more extensive master slave chip arrangement (it will be tight) like the 80286 such that the board itself as a slave could call another sub-slave (or DMA controller).
Or we could redo the complete board and move it up to a 68020. The 68020 had one neat feature, you could dynamically choose the bus size you want—8, 16, or 32 bits with two external pins on the chip. This for example allowed you to use a single boot ROM instead or 2 (or 4) as was the case in the with 16 bit wide systems. They also picked up on the Intel idea bus buffering by using an efficient "cache". The cache in the 68020 was only 256 bytes deep and works a little differently from the 8086 queue. If a jump occurs to a point in the queue, the queue was flushed and reloaded. But the cache looks just like memory, so a jump to a point in the cache would not cause the cache to be dumped and reloaded. If loops are small enough, they can execute directly from the cache.
The second two upgrades would definitely require one (or more prototypes), and realistically would not get out until Autumn for #3, probably August for #2.
What do you guys think.
John
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Edward Snider
Sent: Monday, June 2, 2014 7:27 AM
To: n8vem...@googlegroups.com
Subject: Re: [N8VEM-S100:3893] Re: Possible run of S100 V3 68000/68010 CPU boards
Sure Ian, you are down for 2 boards.
We have enough interest that there will definitely be a run once the updates are made to the board.
Update on who wants boards...
1. Fabio Battaglia - 3
2. Paul Birkel - 1
3. Todd Goodman - 3
4. Brian Marstella - 1
5. Jerry Brumble - 2
6. Gary Kaufman - 2
7. Andrew Bingham - 1
8. Matt Turner - 2
9. Yoda - 1
10. Andrew Kwan - 1
11. Ian May - 2
Total: 19
On Monday, June 2, 2014 8:40:52 AM UTC-5, Ian May wrote:Hi Ed,
Could you put me on the list for 2 of the updated 68000 boards please?
Cheers,
Ian.
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