Hardware, ZETA SBC V2 + 8 inch floppy drive


Basically the ZETA SBC V2 (from Sergey Kiselev) with RomWBW always has the 3.5 inch drive with 720KB or 1.440KB preset. But why not connect a nice old 8 inch floppy disk drive? I still have a NEC FD1165 in my drawer, out with it, it won't get better from lying there.

ZETA V2 with NEC FD1165
ZETA SBC V2 with NEC FD1165

I have written a lot here for the operation of 8 inch drives under DOS. Important is the power supply and the conversion from 35p to 50p. For this I use the FDADAP floppy disk adapter from dbit. Works very well.

Before you can use the ZETA V2 with another floppy drive, you have to rebuild the ROM and program it. For this, use in a GALEP-5, also works great.

ZETA V2 with NEC FD1165
Changing ZETA2_std.asm / enabling 8"

There's not really much more to say. Wayne Warthen did a great job with RomWBW. I use RomWBW v2.9.2-pre15.

Booting ZETA V2 with 8 inch support
Booting ZETA SBC V2 with 8 inch support

How to prepare an floppy disk (C:) with RomWBW

... formatting ...

For this purpose use FDU.COM, change the settings to 8" drive, and then format.

The 8 inch floppy format is as follows: 77 tracks, 2 sides, 15 sectors per track and 512 bytes per sector. The drive rotates with 360 rpm like a 5.25" HD drive.

The floppy formats are actually just the transfer of the known DOS parameters to CP/M. Furthermore RomWBW uses only MFM and not FM, i.e. it always works with 512 bytes per sector.

... make the floppy bootable ...

syscopy c:=cpm.sys (or zsys.sys)

Do NOT use SYSGEN like you are used to on real CP/M machines. Wayne Warten told me: "SYSGEN is kind of brain dead."

... clear/prepare the directory ...

clrdir c:

confirm with Y NOT y. Took me a while to figure it out!

... work with the floppy ...

Do whatever you want: PIP, boot, ...

By the way

Instead of a real 8 inch drive you can also use a pure 1.2 MByte 5.25 inch drive with 360 RPM. To repeat: The 5.25 inch 1.2 MByte drive was designed among other things as a replacement for the 8 inch drive. All drive parameters are exactly the same, only the number of tracks was increased from 77 to 80.

I am using the M4854-342M from Mitsubishi. This works perfectly.


Well, there have been more difficult easter eggs to find!

Easter Egg in RomWBW
Easter Egg in RomWBW: Mandelbrot set

External links