Date: Sat, 31 Oct 1998 20:12:41 -0500 Subject: Re: The old Vectorbeam days...
Zonn: Glad my info was of interest to you and others.
To answer your other questions:
> #1 Do you mind if I post your letter to a "vectorgames" mailing list? It's a >
list of people pretty obsessed with video games using vector graphics. And > as a
followup would you mind if I placed a copy of your letter on the > Cinematronics
That's fine. I have no problem with you posting this info. One thing: since I'm sending
this from my wife's email account, her name "Jassica Sunday" is being printed as
the sender. Please edit this with my name "Dan Sunday".
[No problem, I chopped off all the headers. -- Zonn]
> #2 You wouldn't have any documentation on the instruction set would you? It > would
be interesting knowing what Larry originally called the instructions.
The instruction set was very minimal, eg: there were no multiply or divide operations.
There was just a shift right with add if a set bit was shifted out. This was used
to do a multiply by repeating it the number of bits in the word. As for the full
instruction set: it was described in one of Larry's patents, namely: US Patent #
4,053,740 (Oct 11, 1977) for a "Video Game System". This patent explains a lot about
both hardware and software, and gives the instruction set in Larry's computer.
[Maybe minimal, but it allowed a 12x12 bit multiply in 24 cycles! Something the 80188
couldn't do, more similar to the 80386! -- Zonn]
When I started working with Larry, we had a Z80 macro assembler with the Z80 assembly
instructions removed. We then had a set of macros defining the full instruction set
plus more for Larry's machine. This let us define, for eg, multiplication as a macro
that got expanded into the correct number of basic machine instructions. I was sure
I had a listing of what all those macros were, but haven't found it yet. I suspect
it's in one of the many unpacked boxes I have. I'll look around.