1 Jun
2000
1 Jun
'00
10:21 a.m.
Sellam Ismail <foo(a)siconic.com> writes:
packages
But can you dedcode 6&2 encoded bytes in
realtime on a 6502? Something
tells me it's not fast enough to do this.
If you're clever enough, you can do it. I previously cited several that did it.
Cant speak for the 6502, but NS* did it with minimal hardware a few years
earlier and it was a respected design. Not a whole lot of ttl on the board
either considering it was S100, Boot prom and FDC.
Allison
1 Jun
1 Jun
6:04 p.m.
Allison wrote:
Cant speak for the 6502, but NS* did it with minimal
hardware a few years
earlier and it was a respected design. Not a whole lot of ttl on the board
either considering it was S100, Boot prom and FDC.
Yes. But the part that makes Woz's design interesting is that he did
it *without* an FDC, and it only ended up as seven TTL chips *total*
(eight if you include the boot PROM).
With an FDC chip, there's certainly a range of design styles available;
I've seen simple and reasonably elegant designs, and gross disgusting
kludges. But the most elegant FDC-based design is still not even in
the same class as Woz's design.
Note that I'm not claiming that Woz's method would be the right thing
to do today. But at the time he did it, it was awesome.
2 Jun
2 Jun
12:26 a.m.
Allison wrote:
Well the NS* controller does NOT use an FDC. IF you kick out the bus
interface (apple for the most part has none) and the fact that apple used
a tweeked disk drive too the NS* controller is really simple with the core
being less than 8 or so chips. Of course back in '77 current ttl s100
interfaces usually added 5-7 chips to any IO design.
Cant speak for the 6502, but NS* did it with
minimal hardware a few years
earlier and it was a respected design. Not a whole lot of ttl on the board
either considering it was S100, Boot prom and FDC.
Yes. But the part that makes Woz's design interesting is that he did
it *without* an FDC, and it only ended up as seven TTL chips *total*
(eight if you include the boot PROM). With an FDC chip, there's certainly a range of
design styles available;
I've seen simple and reasonably elegant designs, and gross disgusting
kludges. But the most elegant FDC-based design is still not even in
the same class as Woz's design.
I don't know, I"d done a few 765 designs (especially 37c65) that were low
on parts and programatically one heck of a lot lighter on the cpu and memory.
Though the best one was my first as that was only 11 chips for the whole
S100 board and did all FDC standards for 8", 5.25" and 3.5" (excluding off
data rate 1.2mb). Stll use that one.
Note that I'm not claiming that Woz's method
would be the right thing
to do today. But at the time he did it, it was awesome.
Yep, it was cheap.
Allison
8922
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