Hi,
I'm trying to expand an AIM65 with some extra memory and IO. I am prototyping it on breadboard, which is connected to the AIM65 via its 44pin connector.
I am using a 74LS245 for the databus buffering, but the unit doesn't work with it connected. I tried a few other '245 chips and checked they were okay - and they were. When I remove the '245 and bridge the databus with wires, everything works okay. However, this is fine for testing, but in real life the databus will run out of puff.
I connected the '245 direction pin to the r/w (-ve w) of the 6502. I connected the enable of the '245 to gnd. I tried inverting the r/w, I tried swapping this and swapping that and to no avail. All signals are strong and healthy and well within the limits of TTL.
I know the '245 chips are okay. And, although I have never seen such a circuit, I assume the 6502 can have its databus buffered.
Any ideas on this one?
rgds,
river
![Confused :?](./images/smilies/icon_confused.gif)