Hi Dave,

Consider my chops busted!!! I did read that ages ago, thought "Bugger, that's not how I've done it. I must fix that." and then clearly got sidetracked and didn't!! Thanks for the reminder and getting me back on track.

Gary

Hi Dave,

PHI2 was the culprit. I've linked the peripheral Phi2 to the CPU Phi2 In and all is working now.

Many thanks to you and also to the others who put up suggestions.

Back to coding now.

Gary



Assuming you are using a W65C02 processor, then yes, it's better to derive the system clock ...

Hi Dave,
CPU schematic attached. Peripheral Phi2 is from the Phi2O pin39. Should it just be linked to PHI2 on pin37 and 39 left out of the socket?

I'm using HCT logic chips across the board (the schematic is showing 74HC00, it's actually a 74HCT00. Must correct that).

Gary



Particularly with ...

Hi Dave,

Thanks for your thoughts. Attached is the schematic of the memory section and a couple of pics of the system as it stands.

The RAM chip tested OK. I had a similar thought so I made up an Arduino test rig to run through the RAM chip and check that values were stored correctly. All OK ...

The JSR is called twice at the end to do the CR/LF and they seem to be fine. It's the other ones that seem to kill it.

Debugging options are limited. I've run the code through a simulator and it seems to be doing what it's supposed to.

Thanks,
Gary

I see, you do not call any jsr, even if it ...

High byte is stuck at $08.

The delay comments are not correct ATM. Lots of fiddling with code and not updating every time!! Once I sort out the issues I'll fix up the comments to be correct.

I've had a look through the MAP file. All seems to be in order. I've attached it for completeness.

Thanks ...

Hi All,

I'd like to tap the collective brains trust of the forum to see if we can sort out an odd problem I'm having.

I have built a small 65C02 based system, 32k RAM, 32k FLASH ROM, I/O at $8000, serial chip at $8500.

The code in the attached file testHex4-Working.S print the hex numbers from ...