I have an Issue 4 with factory disc fitted. I added Econet and then the Beeb refuses to boot and stuck in a loop.
I connected up the Tube Snoop and got this endlessly repeating section.After the memory test/clear and setting up the System VIA, the CPU is called into an endless NMI, it looks like it is reading the Econet Station ID and then when it resets IC97 it causes another NMI. I think it is IC26 as if I lift pin#11 of IC91 and put back S2 the Beeb boots as normal and will show the Econet banner with CTRL+N+BREAK - any subsequent Econet commands are met with "Line jammed" - as per normal with no functioning NMI. Another oddity is pin #7 of IC26 (not connected to anything and should remain high on a normal Beeb) has a 20ns wide "glitch" that isn't supposed to be there. There is no activity on the 6854/ADLC IRQ pin whilst the NMI is spammed.
Has anyone seen this behaviour before?
I connected up the Tube Snoop and got this endlessly repeating section.
Code:
83 a9 a9 83 20 e5 20 0d 2c 18 fe 69 48 98 69 9848 48 a9 20 a9 0f 8d 30 fe 0f 4c bf 96 a9 01 2c a1 fe 20 f0 38 ad ad a1 fe 20 29 81 f0 06 20 4c e8 99 20 4c 99 99 ea 9f a9 82 8d a0 fe 82 a9 67 8d a1 fe 67 60 2c bb ea 99 9f a9 bf a0 96 4c 0e 0d 8c 0d 0d 96 8d 0c 0d bf a5 f4 0f 8d 30 fe 0f 68 a8 99 20 a8 68 68 2c 20 69 2c 20 fe fe 40 20 69 e5 20 83 a9 a9 83...Has anyone seen this behaviour before?
Statistics: Posted by maniacminer — Sun Feb 11, 2024 12:47 am