Vectrex Autofire Adapator

21 views
Skip to first unread message

[HCI]Mara'akate

unread,
Sep 16, 2010, 4:51:49 PM9/16/10
to
I'm planning on building the autofire adaptor as shown on
playvectrex.com: http://www.playvectrex.com/vectech/autofire.txt

but it doesn't state if the caps are polarized or ceramic and if they
are polarized which direction is going where? I noticed this after I
ordered the parts (d'oh!) and I'm guessing they're polarized and the
negative is pointing towards the legs of the IC.

Kokovec

unread,
Sep 16, 2010, 9:35:11 PM9/16/10
to

Negative side of cap usually goes to GND.

VectrexMad!

unread,
Sep 16, 2010, 9:51:00 PM9/16/10
to

This circuit is the classic astable multivibrator mode for a 555
timer.
I would say
for capacitor C, electrolytic between pin 2 and GND, with the "+"
polarity on the pin 2 side
for capacitor C1, ceramic (ceramics are not polarised)

VectrexMad!
http://www.vectex.co.uk

[HCI]Mara'akate

unread,
Sep 16, 2010, 10:29:44 PM9/16/10
to

I got polarized caps of both and radioshack doesn't sell the right
size I need for the ceramic, can I use this polarized one in place of
it with the negative running to the IC or will it not work?

http://www.radioshack.com/family/index.jsp?categoryId=2032267&allCount=111&fbc=1&f=PAD%2FProduct+Type%2FCeramic+disc+capacitors&fbn=Type%2FCeramic+disc+capacitors&filterName=Type&filterValue=Ceramic+disc+capacitors&s=

here is what radioshack carries if I can use something close.

Thanks

Kokovec

unread,
Sep 17, 2010, 12:29:11 AM9/17/10
to
On Sep 16, 7:29 pm, "[HCI]Mara'akate" <emoaddic...@gmail.com> wrote:
> On Sep 16, 9:51 pm, "VectrexMad!" <vectrex...@fastmail.fm> wrote:
>
>
>
>
>
> > On Sep 16, 9:51 pm, "[HCI]Mara'akate" <emoaddic...@gmail.com> wrote:
>
> > > I'm planning on building the autofire adaptor as shown on
> > > playvectrex.com:http://www.playvectrex.com/vectech/autofire.txt
>
> > > but it doesn't state if the caps are polarized or ceramic and if they
> > > are polarized which direction is going where?  I noticed this after I
> > > ordered the parts (d'oh!) and I'm guessing they're polarized and the
> > > negative is pointing towards the legs of the IC.
>
> > This circuit is the classic astable multivibrator mode for a 555
> > timer.
> > I would say
> > for capacitor C, electrolytic between pin 2 and GND, with the "+"
> > polarity on the pin 2 side
> > for capacitor C1, ceramic (ceramics are not polarised)
>
> > VectrexMad!http://www.vectex.co.uk
>
> I got polarized caps of both and radioshack doesn't sell the right
> size I need for the ceramic, can I use this polarized one in place of
> it with the negative running to the IC or will it not work?
>
> http://www.radioshack.com/family/index.jsp?categoryId=2032267&allCoun...

>
> here is what radioshack carries if I can use something close.
>
> Thanks

Negative to GND

[HCI]Mara'akate

unread,
Sep 17, 2010, 4:15:46 PM9/17/10
to

Awesome, I'll give it a try this weekend (hopefully if I find some
time, got some test studying to do) and post the results.

Thanks for all the help everyone!

[HCI]Mara'akate

unread,
Sep 17, 2010, 6:14:43 PM9/17/10
to
On Sep 17, 12:29 am, Kokovec <koko...@gmail.com> wrote:
> Negative to GND- Hide quoted text -
>
> - Show quoted text -

Ahhh, I also forgot to ask... Negative to GND on the vectrex pins or
the GND pin on the IC?

Kokovec

unread,
Sep 17, 2010, 9:36:45 PM9/17/10
to

You should tie all grounds together.
So pin 8 of Vectrex ties to the GND of the IC and negative of Cap.

[HCI]Mara'akate

unread,
Sep 19, 2010, 9:22:10 PM9/19/10
to
I tried making this and all it seems to do is autofire on it's own (I
didn't bother wiring a switch) was this the intention? Flipping a
switch bypasses the fire button on my controller and just autofires on
the circuit? If so this is not what I want at all. I want it to be
more like the Rapid Fire unit for the Sega Master System, or any turbo
controller.

[HCI]Mara'akate

unread,
Sep 22, 2010, 10:27:02 PM9/22/10
to
*cough* no information on this? If this is the function of the
device, then I'm considering tracing out my SMS RF Unit and just
directing the appropriate pins...

Mittens

unread,
Sep 23, 2010, 4:12:04 AM9/23/10
to


Absolutely no guarantees, but here goes with a patch ...

First, you need an extra transistor and resistor to invert the output of
the 555. There's no getting away from that I think. The transistor can be
anything small and NPN, e.g. BC548, (2S)C1815.

Break the connection between the Vectrex and pin 3 of the 555. Connect pin
3 of the 555 to a 10k resistor. The other side of the resistor connects to
the transistor base. Transistor's emitter goes to GND and the collector to
the Vectrex pin 4.

Now break the connection between C and GND. Pin 4 from the controller goes
to the free end of C.

And that's it I think.

Now when you press button 4, you get a stream of pulses appearing on pin 4
of the Vectrex. If you want button 4 to behave as normal, short pin 4 from
the controller directly to pin 4 of the Vectrex with a switch, bypassing
the circuit.


+5V (Vectrex Pin 7)
|
|
.----------+
| |
Z .--+ (Vectrex Pin 4)
R1 Z .__|__|__. |
| | 8 4 | |C
+----7 | 10k B|/ SMALL NPN
| | 3--/\/\---| TRANSISTOR
Z | LM 555 | |\ E
R2 Z .-6 5----. |
| | | | | |
+--+-2 | | |
| |___1____| === C1 |
| | | |
=== +---------+------'
| C |
| |
| GND (Vectrex Pin 8)
|
(Controller Pin 4)

-- mittens

Mittens

unread,
Sep 23, 2010, 4:54:04 AM9/23/10
to
On Thu, 23 Sep 2010 09:12:04 +0100, Mittens <NO_...@mailinator.com> wrote:

> On Thu, 23 Sep 2010 03:27:02 +0100, [HCI]Mara'akate
> <emoad...@gmail.com> wrote:
>
>> *cough* no information on this? If this is the function of the
>> device, then I'm considering tracing out my SMS RF Unit and just
>> directing the appropriate pins...
>
>
> Absolutely no guarantees, but here goes with a patch ...

Thinking about it some more, if you didn't already have the 555 timer chip
I would have suggested a classic astable circuit would do the job
adequately:


.------+---------+-- +5V (Vectrex Pin 7)
| | |
Z 1k Z 10k Z
Z Z 10k Z (Vectrex Pin 4)
| | | |
+------+--. .--+------+
| \ / |
| NPN X |
C \| / \ 1000pF |/ C
|---||--' '-||-+--| NPN
E /| 1000pF |\ E
| |
| |
GND (Controller Pin 4)
(Vectrex Pin 8)

Just 3 resistors, two caps and two transistors.

Again, no guarantees.

-- mittens

Mittens

unread,
Sep 23, 2010, 4:57:47 AM9/23/10
to
On Thu, 23 Sep 2010 09:54:04 +0100, Mittens <NO_...@mailinator.com> wrote:

> On Thu, 23 Sep 2010 09:12:04 +0100, Mittens <NO_...@mailinator.com>
> wrote:
>
>> On Thu, 23 Sep 2010 03:27:02 +0100, [HCI]Mara'akate
>> <emoad...@gmail.com> wrote:
>>
>>> *cough* no information on this? If this is the function of the
>>> device, then I'm considering tracing out my SMS RF Unit and just
>>> directing the appropriate pins...
>>
>>
>> Absolutely no guarantees, but here goes with a patch ...
>
> Thinking about it some more, if you didn't already have the 555 timer
> chip I would have suggested a classic astable circuit would do the job
> adequately:

Of course, it would help if I drew it right...

.------+---------+-- +5V (Vectrex Pin 7)
| | |
Z 1k Z 10k Z
Z Z 10k Z (Vectrex Pin 4)
| | | |

+--||--+--. .--+--||--+
| 1000pF \ / 1000pF |
| X |
C \| / \ |/ C
|-------' '-------| NPN
E /| |\ E
| NPN NPN |


| |
GND (Controller Pin 4)
(Vectrex Pin 8)

-- mittens

VectrexMad!

unread,
Sep 23, 2010, 9:21:24 AM9/23/10
to

Appreciate you might want to dit yourself but may I suggest
http://homepage.ntlworld.com/pascual.nicholson/shop.htm

:)

VectrexMad!

Frank Sapone

unread,
Sep 23, 2010, 10:24:48 AM9/23/10
to
On Sep 23, 4:12 am, Mittens <NO_S...@mailinator.com> wrote:
> On Thu, 23 Sep 2010 03:27:02 +0100, [HCI]Mara'akate  
>

Thanks for this. I'll give it a go probably tonight or tomorrow. I
can use any NPN, such as 2N3904? Ideally I'd like to make it so I can
control all 4 buttons and customize each one individually with
switches (like the SMS RF unit). I know I probably could have used
two 556's but since i got the 555's do I just basically build the same
circuits and Pin 7 and 8's go to the same spots on the circuit and
where vec Pin 4 goes would be Pin 1, 2, and 3 for the appropriate
buttons? Sounds right to me. I'm not worried about it looking all
pretty or anything like that. :P

Frank

Mittens

unread,
Sep 23, 2010, 3:12:51 PM9/23/10
to
On Thu, 23 Sep 2010 15:24:48 +0100, Frank Sapone <fhsa...@gmail.com>
wrote:

> I can use any NPN, such as 2N3904?

Yes that would be absolutely fine I think.

> Ideally I'd like to make it so I can
> control all 4 buttons and customize each one individually with
> switches (like the SMS RF unit).

Can't say I know every Vectrex game, but are there any for which this
would actually be useful? AFAIK, button 4 is usually the fire button and
the others do other things.

> I know I probably could have used
> two 556's but since i got the 555's do I just basically build the same
> circuits and Pin 7 and 8's go to the same spots on the circuit and
> where vec Pin 4 goes would be Pin 1, 2, and 3 for the appropriate
> buttons?

There is a quad version of the 555 too, but if you really wanted to do
this then there are probably better ways to go about it.

-- mittens

[HCI]Mara'akate

unread,
Sep 23, 2010, 4:22:56 PM9/23/10
to
As I've said, it doesn't need to be pretty. What version of the 555
is quad? I'll go about making one with four 555 timers (one for each
button) and then attempt a quad 555 version. This is all for my own
personal use, I would just like the ability to customize having
autofire for all buttons.


Thanks for all your help so far!

Mittens

unread,
Sep 23, 2010, 7:03:15 PM9/23/10
to
On Thu, 23 Sep 2010 21:22:56 +0100, [HCI]Mara'akate
<emoad...@gmail.com> wrote:

> As I've said, it doesn't need to be pretty. What version of the 555
> is quad?

NE558

> I'll go about making one with four 555 timers (one for each
> button) and then attempt a quad 555 version. This is all for my own
> personal use, I would just like the ability to customize having
> autofire for all buttons.

Unless you want to have the autofire rate different for each button or
something like that, it's not very elegant to repeat timers. More to go
wrong. I would try and OR the output of a single 555 with each of the
buttons.

How about this?

+5V (Vectrex Pin 7)
|
| all 10k (repeat transistor/switch for each
button)
.----------+ .-/\/\--
| | | (Vectrex Pin 1 thru 4)
Z .--+ +-/\/\-- |
R1 Z .__|__|__. | +---.
| | 8 4 | +-/\/\-- | |
+----7 | | NPN |/ C o
| | 3--+-/\/\----| / 'Normal Mode'
Z | LM 555 | B |\ E /
R2 Z .-6 5--. | |
| | | | | '-+-'
+--+-2 | | |
| |___1____| === C1 (Controller Pin 1 thru 4)
| | |
=== +-------+
| C |
+--------+
|
GND (Vectrex Pin 8)

Just repeat the resistor/transistor/switch combination on the right for
each of the four buttons. Saves you three 555s and associated timing
components.

-- mittens

Kokovec

unread,
Sep 24, 2010, 2:31:45 PM9/24/10
to
On Sep 23, 4:03 pm, Mittens <NO_S...@mailinator.com> wrote:
> On Thu, 23 Sep 2010 21:22:56 +0100, [HCI]Mara'akate  
>

I like using microncontrollers for this type of stuff myself.
Much easier to deal with in software.

[HCI]Mara'akate

unread,
Sep 24, 2010, 6:32:49 PM9/24/10
to

I don't own the equipment involved to program microcontrollers. I've
also wanted to learn how to do this the old school way.

Reply all
Reply to author
Forward
0 new messages