ACA 1220 or ACA 1232

[LaserBack]

I think it's 16.67Mhz (Standard) - but the chip on mine is marked as an 18Mhz version, but then overclocks to 26Mhz.
 
I will take it apart when I get time and take a pic. It's an extremely simple mod - but you take the risk of overheating your CPU.  That said, i've run mine for hours and checked temperature and its barely warm, so I could have a 'good chip', Motorola are well known for basically having single production runs whereby they then speed and stability test chips to work out how best to sell them - ie. at what clock speed.
 
Wouldnt suprise me if an 18Mhz chip ran OK at 33 or 40Mhz based on how its very luke warm for me at 26Mhz.
 
Anyway, i've got a red PCB for my 1220 - despite it looking green on their website, I think the latest ones are red (mines 4 months old).  With the chips facing upwards and the expansion connector to the left side, if you look to the right hand side just above the RAM and to the right of the CPU there's a little matrix of solder pads.  On the standard 1220 config it has the top link jumpered with what I believe is a 1ohm resistor / link.  The points are very very tiny to solder on so I recommend a good clean soldering iron and fine Kaynar wire or similar.
 
If you look elsewhere on the board there's actually a table printed on the board that shows the clock frequencies when certain jumpers are set out of that matrix of 4.  Actually 8 pins, 4 lots of 2.  
 
All I did is solder 2 wires, 1 from each end of the very small pads and if memory serves it was the top 2 pads (already joined) and the bottom 2 pads that give 26Mhz, and each wire went to a switch - ie. 1 wire to the middle of a toggle switch, the other to the outer pin of a toggle switch.  
 
 
JP1 []---[]  < already has a 1ohm link / resistor soldered in there
JP2 []    []
JP3 []    []
JP4 []    []  < these are the 2 pads with wires to a switch
 
That's it, just dont switch when powered up.  So now you can toggle between default speed and 26Mhz on the 1220.  The switch just shorts those 2 bottom pins (JP4) out which tells the FPGA to run at 26Mhz.
 
You get a wonderful speed boost for normal operations and some of the more intensive games like Frontier and 3D shooters etc gain enough to become a bit more playable.  Just dont expect to be playing Doom etc, you really need 40Mhz+ and actually I think frame rate can suck on anything less than 50Mhz.  For the 3 or 4 games like that I am not bothered personally, the 1220 is the best balance of performance vs cost.

ah ok thx for the info
can u post sysinfo screenshots ie at 18mhz and 26mhz

[Gulliver]

ah ok thx for the info
can u post sysinfo screenshots ie at 18mhz and 26mhz

My guess, he went from about 3 mips to 5 mips in sysinfo.

[GadgetUK]

My guess, he went from about 3 mips to 5 mips in sysinfo.

Will take some screenshots later - need to connect it all up, STFM + Ultrasatan hogging desk and LCD this last few weeks.

From what I remember its faster than a 2500 on everything.  Not sure clock speed of 2500, infact I've never seen one.

[Honkybear]

Just out of curiosity how much is Petro selling the 1200's and does he have any left. Thanks in advance.

[LaserBack]

My guess, he went from about 3 mips to 5 mips in sysinfo.

yep 020 and 030 clocked at 25-28mhz are around 5 mips
my tra1200 it have a 020/28mhz sysinfo reports 5.04 mips

[GadgetUK]

Here's the benchmarking - FLOPS.
 
I've got no idea what other benchmarking tool you guys use, if you post me a link I will DL it and do a screenshot of that also.
 
The nice thing is all the benchmarks I do report it being faster than 3000/25. Note its 26.7 (almost 27Mhz - not 28).
 

 

[LaserBack]

Here's the benchmarking - FLOPS.
 
I've got no idea what other benchmarking tool you guys use, if you post me a link I will DL it and do a screenshot of that also.
 
The nice thing is all the benchmarks I do report it being faster than 3000/25. Note its 26.7 (almost 27Mhz - not 28).
 

for 26mhz 4.77 mips on sysinfo that's ok,
 mine is at 28mhz sysinfo reports 5.04 mips http://www.bigbookofamigahardware.com/bboah/product.aspx?id=145

[djos]

I think it's 16.67Mhz (Standard) - but the chip on mine is marked as an 18Mhz version, but then overclocks to 26Mhz.
 
I will take it apart when I get time and take a pic. It's an extremely simple mod - but you take the risk of overheating your CPU.  That said, i've run mine for hours and checked temperature and its barely warm, so I could have a 'good chip', Motorola are well known for basically having single production runs whereby they then speed and stability test chips to work out how best to sell them - ie. at what clock speed.
 
Wouldnt suprise me if an 18Mhz chip ran OK at 33 or 40Mhz based on how its very luke warm for me at 26Mhz.
 
Anyway, i've got a red PCB for my 1220 - despite it looking green on their website, I think the latest ones are red (mines 4 months old).  With the chips facing upwards and the expansion connector to the left side, if you look to the right hand side just above the RAM and to the right of the CPU there's a little matrix of solder pads.  On the standard 1220 config it has the top link jumpered with what I believe is a 1ohm resistor / link.  The points are very very tiny to solder on so I recommend a good clean soldering iron and fine Kaynar wire or similar.
 
If you look elsewhere on the board there's actually a table printed on the board that shows the clock frequencies when certain jumpers are set out of that matrix of 4.  Actually 8 pins, 4 lots of 2.  
 
All I did is solder 2 wires, 1 from each end of the very small pads and if memory serves it was the top 2 pads (already joined) and the bottom 2 pads that give 26Mhz, and each wire went to a switch - ie. 1 wire to the middle of a toggle switch, the other to the outer pin of a toggle switch.  
 
 
JP1 []---[]  < already has a 1ohm link / resistor soldered in there
JP2 []    []
JP3 []    []
JP4 []    []  < these are the 2 pads with wires to a switch
 
That's it, just dont switch when powered up.  So now you can toggle between default speed and 26Mhz on the 1220.  The switch just shorts those 2 bottom pins (JP4) out which tells the FPGA to run at 26Mhz.
 
You get a wonderful speed boost for normal operations and some of the more intensive games like Frontier and 3D shooters etc gain enough to become a bit more playable.  Just dont expect to be playing Doom etc, you really need 40Mhz+ and actually I think frame rate can suck on anything less than 50Mhz.  For the 3 or 4 games like that I am not bothered personally, the 1220 is the best balance of performance vs cost.

Thanks for this, I decided see how mine went OC'd to 26Mhz by using my hot air station to solder a jumper between the pads on JP4 and it worked like a charm. My 020 is marked as 16Mhz but still only gets warmish when running demo's etc.

As a result (and the fact I mainly use WHDLoad on my 1200) I didnt bother soldering on a switch ... oh and I also didnt want to drill a hole in my mint condition case.