Blizzard 1260 rev1 and rev-II difference?

[keropi]

Hello!
anyone knows what is different on Blizzard 1260 REV-II from the non-rev marked boards? (I assume they are rev1 ones)
I have a Phase5 1260 that has no revision marking on the back of the PCB and comparing to the revII images on the web I found a resistor difference: my rev1 board has it populated
So I was wondering what are the changes - probably this info was lost in time or never public knowledge but maybe someone has some insight
thanks!

 

[roy_bates]

i probably wont be much help,but,if i remmeber corectly chucky was reverse engineering these at some point maybe its worth asking him

and,it looks like its something to do with the realtime clock,so probably no difference worth noting,corrct me if im wrong

 

[Boing-ball]

Have the Phase 5 and had the DCE versions. The latter had a non-rechargeable RTC battery. Whilst the Phase 5 used a rechargeable one. Not sure if these were classed as Rev 1 (Phase 5) and Rev 2 (DCE).

 

[keropi]

I do not know chucky to ask anything - perhaps he replies here if he is a member
but there are definetely revII boards from Phase5 - one is pictured here: https://amiga.resource.cx/photos/photo2.pl?id=blizzard1260&pg=4&res=med&lang=en
I would guess the DCE versions would be the REVII boards - makes sense to produce the latest rev

 

[roy_bates]

i would go with what boing ball suggested,i do remeber they started fitted non rechargable battereies at some point and the resistor is the feed from the 5 volt rail

its easy to find out,itll have the voltage one side on one pad for the charging circuit

 

[keropi]

I doubt such a change would warrant a rev II marking on the pcb
but if this comment is about the extra resistor on my pic then on amiga.resource site there are 3x front photos and 1x back photo
all 3 boards use the same VL2020 rechargeable battery - and only 1 has the extra resistor like mine
could be dependent on the rtc chip used, we cannot see it since it's under the battery

edit: checked mine, left side of resistor goes to a pin on the 1200 mobo connector - right side goes to a pin of the MACH21 chip above the battery

 

[roy_bates]

slightly different firmware? who knows

 

[keropi]

I wonder what this trapdoor pin is

 

[roy_bates]

one of the data lines? i cant think which one at the moment

 

[keropi]

seems like it's pin85 on backside of pcb - I cannot for the life of me get a google search result of the pinout

 

[roy_bates]

68? data line d8?

 

[keropi]

if this is to be believed: https://allpinouts.org/pinouts/connectors/buses/amiga-1200-cpu-port/
it is RESET signal

 

[roy_bates]

hmm,maybe its for the disable card feature?

i need some tea,lol

 

[keropi]

heh no idea... and I realized the numbering is even on front side of mobo - odd on backside , hence the correction of pin #