Multibank CP/M

[Witchy]

Hi folks,

I'm puzzling why the US CP/M R2.2 Multibank edition won't boot on my European QX10, but non-multibank 256K R2.2 works fine. Does it require a RAM board to work successfully, or DIP switch changes?

Cheers,

 

[brijohn]

Hi folks,

I'm puzzling why the US CP/M R2.2 Multibank edition won't boot on my European QX10, but non-multibank 256K R2.2 works fine. Does it require a RAM board to work successfully, or DIP switch changes?

Cheers,

By Multibank version you mean B2.27? In what manner does it fail to boot?

I can't think of any reason it should not boot. I've used it on booth my US QX-10 and QX-16 systems and it boots fine. There is no need for any RAM board. It does support accessing an extra 256k of RAM when used on a QX-16 (which has 512k instead of 256k), but that should not prevent it from being used on a QX-10. I'd have to check what my DIP switches are set to, but I didn't have to make any changes on the machine I own to get it working.

 

[Witchy]

By Multibank version you mean B2.27? In what manner does it fail to boot?

I can't think of any reason it should not boot. I've used it on booth my US QX-10 and QX-16 systems and it boots fine. There is no need for any RAM board. It does support accessing an extra 256k of RAM when used on a QX-16 (which has 512k instead of 256k), but that should not prevent it from being used on a QX-10. I'd have to check what my DIP switches are set to, but I didn't have to make any changes on the machine I own to get it working.

Yep, B2.27. It boots, brings up the 'device assignment' text for A:, B: and M: drives but then locks up. All of Don Maslin's disks do this, but your CFdisk boot floppy doesn't because it isn't a Multibank version, just a 256k version. The QXPC floppy does, I'm guessing because that's a Don disk. To get the QXPC running I boot from the cfcard disk then run QXPC from the B: drive. The European multifont CP/M 2.2 disk and CP/M 3 disk won't read the Don disks or your cfcard disk. It's very odd!

Cheers

 

[brijohn]

Yep, B2.27. It boots, brings up the 'device assignment' text for A:, B: and M: drives but then locks up. All of Don Maslin's disks do this, but your CFdisk boot floppy doesn't because it isn't a Multibank version, just a 256k version. The QXPC floppy does, I'm guessing because that's a Don disk. To get the QXPC running I boot from the cfcard disk then run QXPC from the B: drive. The European multifont CP/M 2.2 disk and CP/M 3 disk won't read the Don disks or your cfcard disk. It's very odd!

Cheers

It might be any issue with bad memory, I've had at least one machine that behavior somewhat similiarly and had a bad RAM chip that needed replacement. Though i'm unsure why the B2.20 version woulds work in that case. Still you could use the DIAG disk from one of Don's disk sets and see if it detects any issue with the installed ram. You'll need to set the DIP switches to tell the diag program how much memory you actually have.

The reason the CPM 3 disks and multifont disks won't read Don's disk or my cf disk is that they use different formats. CPM3/Multifont uses 16 sectors of 256 bytes per sector and B2.2x disks uses 10 sectors of 512 bytes per sector.

 

[Witchy]

It might be any issue with bad memory, I've had at least one machine that behavior somewhat similiarly and had a bad RAM chip that needed replacement. Though i'm unsure why the B2.20 version woulds work in that case. Still you could use the DIAG disk from one of Don's disk sets and see if it detects any issue with the installed ram. You'll need to set the DIP switches to tell the diag program how much memory you actually have.

That was one of the first things I did when I was trying to work out why the graphics mode on my machine has all the pixels shifted one pixel column to the right. Passed ok, but you've reminded me I need to change the dip switches themselves because switch 8 is broken and I don't know if it's stuck on or off.

The reason the CPM 3 disks and multifont disks won't read Don's disk or my cf disk is that they use different formats. CPM3/Multifont uses 16 sectors of 256 bytes per sector and B2.2x disks uses 10 sectors of 512 bytes per sector.

"Compatibility? We've heard of it". Sigh