I played around a lot with hysteris and different values for the resistor. a 27k instead of the 47k did do a better job according to my Oscilliscope, but in practical terms not enough to justify changing the design.
One more thing to add is if anyone is going to try this... I only needed a volume level on my Panasonic rq2102 of about 4.25. You don't need a ton of volume. Actually more volume is worse because you get hum and distortion. That is why I was looking for a solution that works with a low volume. These...
OK, I finally gave up on trying to get a consistent load with the ACI and ground instead of -12v. I got better results since I swapped out the eprom with one Vince provided that was programmed with a version of the Montior that has the correct intercept vectors that apparently Krusader messes up. Bu...
The issue with USB keyboards using a ps/2 adapter is that they need to actually support the ps/2 protocol and speed. The little dongle adapter just re-wires the end. So your usb keyboard has to be made for the adapter. Newer keyboards typically don't bother. There are real adapter boxes that change ...
I'm not convinced it is the EPROM, at least in my case, although I'd be happy if that is it. I've verified that I can consistently read my EPROM (e.g. running a program that calculates the checksum) and get the correct data. I've also tried using an EEPROM and running the ACI firmware out of RAM. I...
I want to do a little dev work on a bootloader and need to know if the built in terminal and serial port are at IO ports 20/21 like a real MITS SIO2 port 0.
OK I was looking for something else and found the can I though I threw out. The paint color is Rustoleum Professional Safety Blue #7524. This is a bit darker than the real Altair, but looks great with the black panel. If you really want the exact color of the Altair I have that paint mix, I had comp...
This looks great! As first step of customization I would also like to color the box of my micro. How did you manage to get such a clean edge of the blue color on the upside of the box? I once tried something similar but the color crept below the masking tape so the result was ugly - for that reason...
I already went with 1% resistors and even swapped all the chips (except the proms) with a working Apple ACI. Still can't get it to work right on an Apple-1 or Replica-1. I do get better results on the Apple-1 since it returns to the monitor, but I get a bad load. On the Replica-1 it doesn't even ret...
Well, here is my update on my ACI not working.... I did replace my Replica-1 EEPROM with the EPROM. My replica-1 is the lastest revision. I am using a wall wart and tried it with an iPod classic (max, 90 and 80% volume), iPhone 4 (max, 90 and 80% volume) and with a Panasonic RQ2102 (At multiple volu...
Jeff, If I get a chance I will build mine today or Monday (World Maker Faire is this weekend, and my son didn't build the ACI last week like he promised). I was planing on using 1% resistors for the voltage divider just like the real Apple-1. If you want I can test by building with the 5% and create...
Put lots and lots of flux on it, then try the solder sucker and maybe braid. I have noticed that the thinner solder needs a lot to flow and be sucked away. Just be careful and use a temperature controlled iron. You can easily lift some of these traces on the board if you out too much heat. If you ha...