Oh Heck!! A Bug in ROM Basic

This could be the ideal place to post details of any bugs or errors found in our PCBs and/or supporting media.
Post Reply
Site Admin
Posts: 7
Joined: Sat Jan 22, 2022 5:56 pm
Location: Chandlers Ford UK

Oh Heck!! A Bug in ROM Basic

Post by bartleph »

I guess it had to happen....a bug has appeared in the D/C/W/M EEPROM I supplied to some of my customers. They will be the ones who have purchased the Floppy Disk Interface board. In the 32k x 8 ROM at offset 0x2608 It should be $A7 but I have found some with $AF. (This actually resides at address $A608 in the 6502SBC) This bug manifests itself in BASIC-in-ROM only where you type A=xx where xx is any number. After a carriage return, the system will return a BS error (Bad Subscript not BullShit!!) If you were to type LET A=xx the problem does not occur.

As an EPROM programmer converts original address contents from $FF to whatever, it is possible to correct this error without having to erase the Eprom.

So. In your Programmer read the chip into the buffer. Change contents of 0x2608 to $A7 and then program the chip.

If you are having difficulty, please email me at [url]mailto://paul.bartlett@btopenworld.com[/url] and I will do my best to help.
I don't profess to know everything, I think I know some things...in between there is always google!!

Post Reply