*** M E M O R U M ***

Is the stuff that CP/M does calling via 0xFFF9 documented somewhere. I can see the call ends up loading 0x34 sectors to CE80 but not how you set which sector to start or what happens if you call it multiple times. The FDX technical manual section 1.6 has the basic details of the high memory allocat...

Since CPM doesn't know anything about partitions, on boot it just reads track 0, sector 1 (of 128 bytes) to 0100 and then jumps to 0100 with the stack set to 0200. The silicon disc code looks for C3 01 40 to make sure the image is valid (JP 0140) but the CF code, like the original floppy doesn't. It...

I always used Newword in non document mode for creating assembler files.

It came with the system and is a heck of a lot more friendly than the CPM editor ED.COM.

USER MTX is basically the original Memotech code for USER LOAD tweaked to account for the differences between disc basic and tape basic. It only works for single file MTX files, as any 2 stage loaders are going to be calling the rom's tape loader directly, and patching the rom isn't an option. That ...

All RB.BAS does is read in the real game file RB.DAT and run it.

load in RB.BAS,
add in
30 STOP
40 USER SAVE"RB.BAS"
50 GOTO 10

Start that with GOTO 40, and from then on it'll auto run.

And I agree, the sound track is pretty good !

It should already boot as 18. But probably will also have C and maybe F configured I can't remember. But if it isn't, booting into CPM with return held down bypasses the disc boot and runs the monitor instead, from that command prompt type BB18 And that should boot off the B drive configured as type...

You just could try it! Grab the Rememotech distribution package from Andy's website. Write the SDdisc.Bin package to your 4 meg card with a imaging program Configure it as a type 18 drive but don't fill more than half of it. It might work. CPM has very simple allocation rules and just uses the first...

Is there anything in that one that's not in the last dozen or so pages of the FDX technical manual ?

The address decoding is 90% done in the PAL/GAL so that ought to be testable in the programmer.

The last 10% being done by the 74LS00 at J10 selects between rom B and rom C if the page roms are active.

A couple of thoughts: The change at 9D looks like someone's done the timing chain mod from page 47 of the service manual, R32 and R33 look to have ben replaced, you can only see one of them in the photo, but the wrong colours for a 560R. R35 and R36 have been pulled as per the mod. The CMOS chip's d...