floaty pin

[grobda]

ive got a galaxian bootleg pcb.

i got to a point where it ran the test rom

then it stopped

after investigating i found touching data bus 7 line made it work

i traced continuity from the cpu to the ram and eprom and it all looked fine

i replaced the cpu, ram (7n,p) eprom (7f) and the 245 buffer (9b) and it made no difference

i ended up putting a 4.7k resistor between db7 and gnd. this works, but im still puzzled why its doing it in the first place.

anyone enlighten me on possible causes?

 

[grobda]

never mind, problem stopped when i put a galaxian rom in

 

[bomjac]

Another worker ? Feverishly off to check the spreadsheet

 

[IDCHAPPY]

, 5 down 145 to go eh Rick/Dave?

 

[grobda]

heh im running out of spares already ;p but yes, another galaxian lives

 

[bomjac]

Well, I do have a few boxes of "spares" lol

 

[IDCHAPPY]

Well, I do have a few boxes of "spares" lol

You only have to climb over 12 goliaths to get to them

 

[grobda]

ill make a shopping list then;

2101 rams

z80 cpus

2716/2732 eproms

(lots of these were dud or just missing)

galaxian colour proms. theres all sorts of funky galaxian colours going on here.

need more info on how hacks work. jims gonna lend me a moon cresta. couple of the proms seem to be moon cresta so nice candidates for converting. the cvs hunchback hacks im totally lost on; its all piggyback chips and broken kynar wiring.

 

[Equites]

Well, I do have a few boxes of "spares" lol

I could sure use some.