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Cromemco JS-1 Joystick Replica

nullvalue said:
LOL @Hugo Holden I just happened to go back to guy's listing and now there's a 8-switch listing, was that by request from you? I'm gonna order from that listing too :) Except it looks like there's not multiple quantities available. Could you ask him to keep it listed for another order?
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Yes, I asked him about ordering 8 and if he would ship to AU. The shipping is somewhat fierce at $39.30 USD (which is about $60 something AU). Yes I will ask to to make up other listings for 8, if I buy them.
 
I think what we should do with the audio and speaker issue for the replicas:

Since there is a tag strip assembly there, we simply add another identical one beside it. There is room. It will carry the components for the class-B amplifier and we will make it with the period correct transistors. I will finalize and test the design and do the layout of it on the added tag strip, so as to make it at least look like it belongs to the era this unit was made.

This way we can get more audio power into an 8 or 16 Ohm speaker.

I think this is likely needed anyway. My assessment of the original system with the 45 Ohm speaker only being any good to the tune of about 50mW at best, suggests that it would have a very modest volume, about that of a small transistor radio, likely ok in a quiet room, but not enough if it was a noisy environment. It needs a little more steam.

Does anybody know a good link to the D+7A board schematic ? The one I found on S-100 computer was not really clear enough.
 
Hugo Holden said:
Does anybody know a good link to the D+7A board schematic ? The one I found on S-100 computer was not really clear enough.
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Is this one better?

Just my two cents....I'm not doing the work, but if my understanding is correct, the audio is TTL level initially, with a, somewhat weak amplifier, in the case of the console version. Why not just take the audio bit and GND to a terminal or an external jack? This leaves the design almost identical to the original (assuming that you duplicate the 45 ohm speaker and amplifier as per the console) and allows the end user to use an external amplifier of their choosing? Again, just an opinion.
 
syzygy said:
Is this one better?

Just my two cents....I'm not doing the work, but if my understanding is correct, the audio is TTL level initially, with a, somewhat weak amplifier, in the case of the console version. Why not just take the audio bit and GND to a terminal or an external jack? This leaves the design almost identical to the original (assuming that you duplicate the 45 ohm speaker and amplifier as per the console) and allows the end user to use an external amplifier of their choosing? Again, just an opinion.
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I'm not sure that it is "TTL". I have only just seen a version of the schematic I can read (Thanks for that link) .

It looks to me so far that the audio signal is derived from the output of the DAC and passed via CMOS selectors that are not digital, in the sense that they act like analog transmission gates. But I am still working the circuit out.

The selected analog output feeds the transistor driver(which feeds the speaker). Since they had it feeding an emitter follower running from the 5V rail in the 45 Ohm speaker case, it is unlikely the dynamic voltage dipped below zero volts (but I don't know, it could potentially go close to -5V). But probably the pp voltage swing there is 5V. If it was larger that would cut the transistor off, making for nasty sounds. This could make the 100R speaker connected to -5V a much better option than the 45 Ohm version connected to ground.

I think the trick is to make the audio driver for the speaker accept a pp input amplitude of close to 10V without any significant distortion, then it will be ok whatever the case of the driving signal.
 
Are you still looking for someone to cut your panels for you? I'd be happy to take a run at it.
 
DougM said:
Are you still looking for someone to cut your panels for you? I'd be happy to take a run at it.
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Really? yeah that would be awesome.. I did acquire some (cheap) diamond files and was considering doing it by hand but I have no experience with this kind of thing. If you have done this kind of work before then that would be great. What would you require? I'm assuming you'd need some kind of printable cut pattern/template?
 
nullvalue said:
Really? yeah that would be awesome.. I did acquire some (cheap) diamond files and was considering doing it by hand but I have no experience with this kind of thing. If you have done this kind of work before then that would be great. What would you require? I'm assuming you'd need some kind of printable cut pattern/template?
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Just the box and a drawing :)

Let me know if you need more details on what the drawing should look like.
 
As if we don't have enough parallel conversations going on, I wanted to throw out one more question - that is what's the best way to do the decals/logo? At one point, I had tried the toner transfer/acetone method (for a different project) with some iffy results, at best. However I'd be hesitant to even try that method here because the enclosures are pre-painted and I wouldn't want to risk the acetone damaging the paint. Does anyone have any suggestions on how to do decal transfer onto painted metal?
 
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Hi,

R/C radios are setup for airplanes, helicopters and boats ... the left arm is throttle up 'n down so that's why it doesn't return anywhere, the left right function is rudder so after the turn, the rudder needs to return to straight.

.
 
nullvalue said:
Yeah I'd rather not guess so if you have some examples on a format you'd prefer, please let me know.
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Here's what I usually put together before I head down to the shop. Obviously all of these numbers are made up.

Once I have the thing programmed into the machine I can cut a sample faceplate and you can test fit before I actually try to cut the box. That might avoid $34 mistakes.Sample Drawing part.JPG
 
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