Co-Co Ram size detection?

[heatsink128]

Hi All,

just got my mitts on a Trs-80 Co-Co, the silver original model, how can I see how much memory it has, as they sold with 4k, 8k,16k,32k etc?
Cheers!
Chris

[sixxie]

AIUI:

4K: PB2 of PIA1 tied LOW
16K: PB2 of PIA1 tied HIGH
32K: PB7 of PIA0 linked to PB2 of PIA1
64K: PB6 of PIA0 linked to PB2 of PIA1

So basically, test the value of PB2 on PIA1 and whether it changes or not when you write appropriate values to the B side of PIA0.

Color BASIC (late enough version to support >=32K) just changes the entire upper 4 bits to PIA0 to see if it affects the RAM detect line, as it doesn't care if it's 32K or 64K - it's only going to use 32K anyway.

Edit: er, of course all *you* have to do is type "PRINT MEM", then worry about 64K later...

[heatsink128]

Thanks sixxie,
Well PRINT MEM gives me 8467 I have extended basic ver1.0.
So is that 8K then??
Cheers,
Chris

[sixxie]

16K! 6K reserved by default for graphics (4 * 1.5K pages) by extended basic.

[zephyr]

Well PRINT MEM gives me 8467

That should be 8487 bytes. Typing 'POKE25,6:NEW' at the command prompt should give you 14631 bytes.

[heatsink128]

Thanks guys, yep I miss-read it. My technical skills revolve around typing CLOADM
All the best,
Chris

[heatsink128]

Confirmed my machine is 16K, will run Deathcase 3D but Glove is a No-Go.

[jmk]

Bad luck with the 16K, but there are an awful lot of them out there. At least you didn't get an ultra-early 4K model. (Or maybe they're worth more?)

Upgrading might be possible...

I use this site whenever I see a CoCo on eBay, it has details of a fair number of specifications for various serial numbers:
CoCo Lounge.

[heatsink128]

Thanks for the link, really interesting site. Was the CoCo 3 released in the UK BTW?

[jmk]

Was the CoCo 3 released in the UK BTW?

No, it was out in the US, Canada and Australia (maybe NZ?) I don't think it was out anywhere else.

Being released in Australia does mean that there are PAL versions that can be picked up... Sadly, I don't have one.