Re: Titan Accel-//e info??

[zcaa1122@rpool9.rus.uni-stuttgart.de (Wulf Hofbauer)]

In article <64C97B6E@rook.wa.com>,
brian hammack <BRIAN.HAMMACK@rook.wa.com> wrote:
>     Greetings, kids.  I visited my old college today and as a doorprize
>for being a good sport (having waited 3 years to get my sheepskin; I
>graduated in '91) my mentor gave me a //e.  Now I have a pair.  :)
>
>      Upon getting the thing home and popping the hood, running it
>through SlotScan, and all that stuff I discover that it contains in slot
>3 a Titan Technologies "Accelerator IIe" card, which turned this 6502
>with 64k in the aux slot (visual inspection) into an enhanced 128k
>sucker going sufficiently faster than 1mHz (help me, Bob Claney, I don't
>know HOW fast it's going but Atarisoft's Battlezone cooks!)...

This card is a 3.5 (3.58?) MHz 65c02 based accelerator with it's own RAM.
It doesn't make the machine an "enhanced //e" because it doesn't have
the enhanced ROMs. It would however be possible to load any ROM contents
you like - on startup, the motherboard ROM contents are copied to RAM
on the card, and by using (undocumented) softswitches, you may reload
this RAM if you like. I have an old magazine describing this procedure in
detail.

>     On the top of the card is a bank of 8 dipswitches and to the right
>of that (over a couple chips) is a group of 7 jumpers -- well, six and
>the second pair of pins is open -- and I want to know what these do.

The DIP switches should set the processor speed during accesses to
peripheral slots. Execution timing is very critical for example when
accessing a Disk ][ (which is normally installed in slot 6), so the
card will switch back to 1 MHz temporarily. I don't know about the
jumpers, maybe I can look it up.

>would like to put the card in my souped //e (enhanced, 1.5 megs RAM in
>the aux slot, 1mHz) and still have everything work -- I figure that via
>a jumper and a flipped switch I can use all the memory in both cards
>(slot 0 and 3) plus get that tasty speed, and hope that having two 65c02
>chips on the system won't cause any hardship/conflicts.

I doubt you can accelerate more than the standard 128K of RAM, but frankly,
I don't know. The card won't conflict with the standard processor, the
motherboard chip is halted by using the DMA line. Supposedly it is possible
to run the computer without a CPU installed on the motherboard. The
magazine I've read told that the motherboard RAM isn't used any more (and
from this arises my scepticism), but this can't be entirely true
since the video controller can only access the motherboard RAM...

- Wulf

-- 
 ________________________________________________________
|                                                        |
| Wulf Hofbauer | wulf.hofbauer@studbox.uni-stuttgart.de |
|                                                        |