Re: Laser 3000

[Lonnie McClure <lmcclure@delphi.com>]

In a message dated 2-6-95, Douglas Spence said:
 
     "So I presume this means that there is no such thing as
      an external floppy controller for the Laser 128 that
      would be compatible with the Laser 3000?"
 
You mentioned later in your message the system bus is 72 pins. I
cannot recall offhand how many pins are on the Laser 128 expansion
bus, but it was the same number as a standard Apple II slot. Hmmm...
let me open my IIgs and check.
 
A quick count reveals 50 pins. The bad news is, that means no plug and
go compatibility. The good news is that means a good chance all the
signals are there to hack in a IIe type controller. However, whether it
would then be recognized or not is another matter.
 
The problem is, I assume you don't have any of the pinouts (as few
computers come with manuals that have full tech specs...assuming you
even have the Laser 3000 manuals).
 
You might want to try contacting Video Technology. If they are nice folk,
they might be able to get them to send you some info on the L3000. You
never know until you try. I once got a photocopy of a manual for a printer
buffer from a company that had been out of business for years! (Long story,
but to make it short, I actually ended up talking to a "sister" company
that was in an entirely different field).
 
 
     "The Printer port has 20 pins (10/side), the System
      Bus has 72 pins, and the RS232 port has 30."
 
The printer port should be the easiest to puzzle out. Using a multimeter,
while sending a continous stream of CHR$255 to the printer, you should
be able to find the which pins are active and which are ground. (Hmmm...
but if no printer is properly attached to the ACK line, it would stop
after the first character...so much for that bright idea).
 
I wonder if there is more than meets the eye on that RS-232 port. Even
if one half of those pins are ground, 15 pins more than is necessary for
RS-232.
 
 
     "Which sound chip is it, and what other 8-bit machines
      had it?"
 
If I recall correctly, it is the AY-3-8910 (or something like that).
The chip, or a compatible version, was used in the TI-99/4A, MSX machines,
the Atari ST series, the Coleco Adam, and some other, rarer machines
you may not have heard of, such as the Timex-Sinclair 2068, Memotech MTX-512,
and Spectravideo SV-328 (and SV-318).
 
 
     "What does the ad you've seen say about the L3000?
      I presume you still have the ad, or have a fantastic memory? :)"
 
I am certain I still have the ad around here somewhere, as my
computer magazine collection dates back sometime. However, I was going
on memory when I posted the last message.