Re: Working on a //+

[Stephen Shaw <xstephenx@apple2.org.za>]

On 09 Sep 2001 09:12:37 GMT, Michael J. Mahon wrote:

> Ralph Glatt replied:
>
>>Hi, Mike, thanks for responding! Yes, I earlier posted about a problem
>>with my Apple ][+. I did take apart the power supply, but I didn't see
>>anything leaking. I'll pull it apart again and give it a thorough
>>looking over, though. As for the cards, I had a 16k card plugged into
>>slot 0, the 1 meg RAM card in slot 3, and the floppy drive card in
>>slot 6.  With this setup, I had the clicking problem. I took out the 1
>>meg card and the problem vanished. Tomorrow, when I check out the
>>power supply, I'll take along a DOS 3.3 master diskette and a cleaning
>>kit. With my luck, a capacitator WILL be out, and I won't be able to
>>tell which one!
>
> You won't, in general, be able to judge the health of a capacitor by
> sight.  It can look perfect and be dried-out.  The easiest way to
> "test" a capacitor for low capacitance is to "bridge" it with a known
> good capacitor of similar or better voltage and capacitance ratings.
> In the power supply, this should be done carefully, and with clip
> leads.  If the supply works with a cap bridged, that cap needs to
> be replaced.

PLEASE!!! When you do this "bridge" test 
a) Only do it with one hand - keep the other in your pocket to prevent an
electric current path across your chest which may make your heart stop or go
into fibrillation.
b) Try and use an isolation transformer to connect the power supply to your
house supply - again to minimise chances of shock
c) Remember there are HIGH VOLTAGES in a power supply. They are AC and DC. AC
"tickles" you. DC grabs you (causes muscle lock up) and (to my mind) is even
more dangerous than AC.

TREAT ELECTRICITY WITH RESPECT! 
I still want you around to collect more Apple IIs :-)))

>
>>As for the sound, I have an old program that digitizes sound from the
>>cassette port. No, it won't sound great, and the sound clips won't be
>>long, but they don't need to be. What I'd really like to do, if I ever
>>get my ambition up, is to make a Doom clone for the Apple //. No way
>>will it be as good as Wolfenstein 3D, but I don't intend it to. It'll
>>be made for a //c, or a //e with 128k and a mouse card. (A REALLY
>>ambitious project!)What matters most is I'm having fun with it.
>
> Good lick--getting playable speed will be a problem--even without
> sound...  And you will not be able to do _anything_ else while a
> sound is being played--it takes the Apple's full attention to do the
> precise timing required to control the speaker.  It _is_ possible to
> play very short sounds interleaved with game play, to make game
> sounds, for example.  Using a softDAC player permits game sounds
> to be anything, not just typical speaker noises.
>
> If you're satisfied with 1-bit samples (ugh!), then you can pack a lot
> more samples into a given amount of RAM. Eight samples per byte
> is straightforward, but run-length compression might get you even
> more, if the sounds don't have much high-frequency content.
>
> You will get much better sound quality, at the cost of space, by
> sampling at 11.025KHz and 8-bits (mono, of course).  Most Macs
> and any PC with a sound card can do this.  You should save the
> sound samples in the "rawest" file format available, like .wav.  Avoid
> compressed formats, which Apples tend to want to make.  The sound
> file can then be moved to the Apple II and get it's .wav (or other) header
> trimmed off in the editor, and you're ready to go.
>
> You can also strip sounds from existing sound files, keeping the
> chunks under the size limit for the Apple II.
>
> -michael
>
>  Email:  mjmahon@aol.com
>  Home page:  http://members.aol.com/MJMahon/

-- 
You mean 15" sparks are supposed to come out of this thing?