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From: rubywand@aol.com (RUBYWAND)
Newsgroups: comp.sys.apple2
Subject: Re: Help I.D.ing cards.
Date: 19 Nov 1995 15:01:31 -0500
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james keim (jkeim@unlinfo.unl.edu) wrote:
> One is an accelerator card--an "M-c-T SpeedDemon"
> It is dated 1984. Does anyone know what speed this thing
> runs? I _think_ I am seeing four 16k 90milisecond cache ram
> chips on it. There also seems to be a little place for
> jumper block on the top of the card, near the keyboard end.
> Any ideas what it might be for? Any ideas if there is a way
> to control this thing through software/hardware? Oh, I did
> notice that the card draws a little Apple on the graphics
> screen before the Autostart ROM kicks in and the "Apple ]["
> appears.
>
The RAMs on our Speedemon are 100ns 2048x8 9128's (for a total 8K of
pretty speedy cache). I once asked McT about the jumper block you
mention, they said the jumper is set at the factory to adjust on-card
timing and to Leave It Alone. (On our card, the jumper block has 5 pairs.
The pair 2nd from the top is jumpered.)
There is also a jumper pair near the bottom middle of the card. This
is the Speed Jumper. Jumper it if you want 'demon to slow down for I/O
accesses to Slots 4 & 5. (The 'demon always slows for Slot 6 I/O ($C0E0 -
$C0EF.)
According to the "Manual" (a folded card), pressing PDL-1
(Closed-Apple on a IIe) upon power-up will engage a self-test. Pressing
ESC at power-up will turn OFF the card and allow running at normal speed.
To turn OFF the card later on, do a POKE (49152+256*S) where S= Slot # of
the slot the card is in; then, press RESET.
You can put the 'demon into any Slot; but, if you put it in Slot 0
(Slot 3 in a IIe), the card will not respond to any KB shut-off commands.
Your card may be a slightly later model. (I've never noticed ours draw
a hires apple on the screen-- darn it!) Possibly, McT came out with a
revision aimed at 128K IIe's.
Indeed, the 'demon is a power gobbler-- roughly 1.5A as I recall-- and
some of the IC's run hot. We finally cut out a square section on the back
of the II+ and added a mini-fan, just to blow air across the 'demon board.
In terms of raw performance (once you arrange for cooling), Speedemon
may be the best of the 4MHz accelerators for early II's. I've never
noticed any compatibility problems and the approx. X3.5 speed increase
puts real 'snap' into your machine's response. (Besides, it's great for
games like Elite!)