CMD Hard Drive - "BOOT ROM" History

HD Boot ROM : V 2.44 Earliest known version. Limited to 500MB Hard Drives/Storage devices.
HD Boot ROM : V 2.58 Minor changes.
HD Boot ROM : V 2.62 Support added for up to 4.04 GB Hard Drives/Storage devices.
HD Boot ROM : V 2.68 DOS bug fix
HD Boot ROM : V 2.78 Partition Directory Fix.
HD Boot ROM : V 2.80 Latest & Final Version.
CMD Hard Drive - DOS History
1.86 First ever Version of DOS
1.92 Latest & Final Version of DOS
CMD Hard Drive - Known Bugs
DOS 1.86 & DOS 1.92

The DOS does not have the ability to prevent the user from using the CD command (Change Directory), on a FILE.PRG.

This can be catastrophic if you are copying files to a Directory, and you use the Wild card "*" to identify the DESTINATION Directory, (using the old version of CMD HD TOOLS. only ! )

This can also occur in immediate mode, if you type @CD:FILE (If the FILE is a PRG file type and not a DIR). This scrambles the pointers and the only way to recover from this is to use the command:

@CD /

CMD Hard Drive - A look Inside

As you can see, It looks a lot like the Control PCB of the 1541-II, with all the well known, 40 pin chips like, 6502, and 2 x 6522's, and a few 74LSxxx chips. The main additional differences are the 3 x GAL custom chips and HD BootROM, which gives the device the ability to talk SCSI, via the 50 pin SCSI port, or External 25 Pin SCSI port.

It also has an 8255 chip for high speed parallel communication, through its parallel port.

It has a battery for the clock, which has about a 10 year life span.

And it has a Display PCB with SWAP 8, SWAP 9 , RESET switches & Activity/Power & GEOS LED's.


Serial port 1 __Serial port 2____Printer Port___Parallel Port____Power plug.


This Page last Updated: 15-10-2018