| Title: | AMIGA NOTES |
| Notice: | Join us in the *NEW* conference - HYDRA::AMIGA_V2 |
| Moderator: | HYDRA::MOORE |
| Created: | Sat Apr 26 1986 |
| Last Modified: | Wed Feb 05 1992 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 5378 |
| Total number of notes: | 38326 |
For those interested in making a MIDI Interface there is a circuit and
description in the following place
tape::user2:[amiga.amicus.am14]midi.zoo
Looks good, But it is untested by me as yet !
-= Pete =-
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 4106.1 | Or, for better results, try... | RGB::SCOTT | Tue Sep 11 1990 20:10 | 11 | |
> > tape::user2:[amiga.amicus.am14]midi.zoo > Slight error in the file name. It should be: tape::user2:[amiga.amicus.am13]midi.zoo (must have been 13phobia!) Rob | |||||
| 4106.2 | Don't build this circuit! | RGB::SCOTT | Tue Sep 11 1990 20:34 | 21 | |
I just looked at the circuit, and unless someone can tell me different, I see some problems. Pin 2 of the serial port (TX data) goes directly into the inputs of the 74LS04. Now, EIA specs state that TX data will swing better than �9v, and the LS04 can take only up to +5v on it's inputs. Similiarly, the LS04 can generate a 0 to 5v swing, so the output tied to pin 3 (RX data) doesn't match the EIA spec either. I'd strongly recommend avoiding this circuit, as driving TTL inputs below ground may damage the Amiga's output port. And reliably reading data in would be problematical. The job is much better done with the new EIA transciever chips from Maxim, or Motorola. They contain a 5v to �12v voltage converter, as well as the right transceivers. Oh, I just noticed what may be another error in the schematic. The parts list calls out a 1n914 diode, while the only diode shown is a 1n73... Rob | |||||
| 4106.3 | Alternative circuit | FORTY2::TATHAM | Nick Tatham @REO | Wed Sep 12 1990 05:14 | 4 |
See also 2375.0. I've built two of the circuits shown there and they both work fine. Nick | |||||
| 4106.4 | no +5v on my serial connector | FSCORE::KAYE | where's my Kama Sutra pop-up book for zero-g | Sun Dec 02 1990 13:13 | 6 |
I tried the circuit in .0, but it depends on +5 on pin 21 of the serial connector. I DON'T have +5 on mine and the circuit diagram in the manual shows no connection. Not sure how the designer had +5v on his? I think i'll use the +-12 and an EIA-to-TTL converter. mark | |||||