[Info-vax] OT: About Digital and divisions

[ChrisQ]

On 11/22/11 12:42, Neil Rieck wrote:

> I recently bought a copy of "The Book" as well. I just didn't want to
> pay full price.
>
> Why? I have always been a bigger fan of Steve Wozniak (in my 8-bit
> days, everyone would see the phrase "WOZ" in the code listings for the
> Apple-2 monitor (anybody remember "call -151") as well as the sweet-16
> routines, the BASIC RENUM routines, the 6502 disassembler, as well as
> other stuff.)
>

...and other stuff like the way that the code in the limited 256 byte
iopage rom space was hand optimised for size so that the same rom sequences
resulted in different instructions, depending on the result of a branch
instruction. Such optimisation is largely dead now, but was quite 
appropriate
in the days of limited address space and memory resources.

>
> While it it true that Jobs was the marketing guru, there wouldn't have
> been anything to market without the creative genius of Wozniak. Anyone
> remember the 7-chip floppy disk controller card? Equivalent cards from
> companies like DEC required anywhere between 40 and 70 chips.
>

I've said it before, but dec never could do kiss hardware design, perhaps
due to the design automation tools they were using, or just an old style
mainframe hardware design culture with an ssi mindset.

Iirc, the Apple ][ floppy controller used a 4 bit latch and bipolar prom
to separate clock and data, with a non standard disk format to simplify the
encode / decode. Way beyond the curve at the time. An Apple ][, Videx 80 
col
card, Programma Pie editor, assembler and 5 meg hard drive bought me lunch
doing embedded 6502 work for 2 or 3 years before moving on to other 
machines.
Never filled that hard drive either, but how the world has changed since...

Regards,

Chris