SCSI2 Hard Disc Replacement Alternative

One of our longer term challenges is establishing an alternative method of loading programs, currently on vulnerable QIC tapes, to the Argus hard drive. However, an alternative would be to have all the tapes pre-loaded on a ‘hard’ device.

We already have a solution developed and fully working for the unsustainable and highly unreliable Winchester disc using Compact Flash cards.  This system is quite expensive as are the professional grade CF cards. So the next step was to see if a different SCSI2 HD replacement card will work with the Argus.  An ‘open source’ product we had our eyes on only has asynchronous support and was originally designed for use with the Amiga computer; see here.  A new version going to be released soon is here; this supports synchronous transfers and will give better perfomance. If the earlier version works then so should the latter. These units use SD cards and are much cheaper that the unit we have installed which uses CF cards. Watch this space.

This is our workshop test rig with the Argus 700 on the left, disc system tray in the centre and FT81 terminal emulation on a laptop.

Argus 700 Test Rig wm.jpg

This is the disc system tray in close-up with the interface card to the Argus 700 on the left, tape drive and tape at the front and the new card on test back right.

SCSI and tape kit wm.jpg

This is the SCSI SD card under trial.

SCSISD Card.JPGThe SCSISD gives the initial boot message, ignore the FAIL and ERROR messages as I have no ME153’s plugged in but it works!

SCSISD Boot Message.jpg

Getting the SCSISD to work wasn’t ‘plug and play’ and I’ll write up how to configure one of these units, I couldn’t load software from tape initially! The proof of the pudding will be running SCSISD in the Launch Conttrol Post (LCP) and see how it performs which we’ll do on Saturday (today).

If it runs in the LCP OK (performance wise) it will represent a big financial saving over the SCSICF product, about a sixth of the price, but then SCSISD is not aimed at high reliability applications in industrial control. We don’t need that. If all works out well I will get several SCSICF units and a load of SD cards with UK and Swiss software loaded so we reduce the need for tapes. That said the tapes look to be loading trouble free at the moment.