Hitachi HL320 Computer


This is a 80C88 4.8MHz machine with 512 KB RAM, 20MB hard disk, 720KB 3.5 inch floppy disk, back lit LCD mono display with connectors for serial port, parallel port and external floppy drive. It has an 11 inch backbit LCD screen with 640X200 or 320x200 pixel CGA display. Unusually for a laptop it has a detachable keyboard with 78 keys. The 12volt Nicad battery was claimed to give 5 hours running time. Back in 1989 you needed stronger knees than one does today, this laptop weighed in at a whopping 16.5 pounds (7.5Kg).There is a rear mounted switch to switch off the hard disk to conserve power. This machine when first marketed was priced at $3,000. Cheaper versions of this machine were equipped with two 720K floppy drives. Working, Japan 1988/9 but the Fuji Electric FK309X-26 hard disk sometimes failed to be recognised. I was seeking a replacement but have discovered that the drive is non-standard. From the pictures below you see that no details of cylinders, heads etc have been marked on the label.

A Google search has revealed that unless the X is significant, the drive parameters are detailed on this page: which indicates that it is an ST-506 MFM 3.5 inch drive with a 40 pin connector which is not to the ST-506 standard which normally has two edge connectors one 34 way and one 20 way, on some of the 3.5" drives these edge connectors where replaced with pins but normally two separate sets. This drive has one set of pins a bit like an IDE drive so it uses a propriety interface basically ST-506 but with a different pin out so this could be what the X stands for in the model number. Some manufacturers used to do this so you couldn't use anyone else's drive in your system, IBM also did this on some of their PS1's using an edge connector on an IDE drive for example.

I was able to boot from a floppy disk and copy files from the hard disk. However I had to hunt out a bunch of floppies and reformat them to 720k. I then made a new boot disk (MSDOS ver 6.2) including Format and Scandisk. Running the latter revealed that there were 4 bad areas which needed fixing. I ran Scandisk twice then Format c:/s. Rebooted twice and seemed fine. I then loaded and run a program and all seemed OK until I decided to install the rest of MSDOS. checking again with Scandisk there was another cluster error. So now was the time to low level format to see if it would be beneficial and I saw that "llformat.exe and" can be downloaded from the internet. Sadly neither worked and the machine went back to its completely uncooperative self (ticking away like a sewing machine)!

I have now stumbled upon the answer! The computer worked fine until the hard disk was switched on, the latter then clicks like a sewing machine. But I discovered that it also did so when the multi pin socket was disconnected (incidentally it is identical to an IDE one) but with the power plug in place. Powering the hard disk from an external computer power supply brought the old thing back to life, it would boot from the hard disk and I have tried one or two programs on it. So I guess the problem was due to the voltage sitting down when the hard disk was asked to run and the on board electronics hunting. When the battery was new there would be sufficient buffering to absorb these variations, but over time the latter has faded and now beyond redemption. I have wired up a 12 volt 5 amp power supply originally used with a Digifusion set top box to the socket for the battery terminals.


Inside view The hard is disk on the left and the floppy disk on right. The memory chips are below the keyboard cable with plug. Note the date code (8809) on the battery.