Search Ebay for "7900A" and you'll find it. Missing front screen. There was a day when I'd give most anything for one of these. Now I have a good supply so I thought I'd mention it in case anyone needed one. Anyways... the 7900A is one of the few HP drives that doesn't use a sector surface, it uses a glass reticule. If someone gets this drive and it needs work, let me know as I do have all the service manuals. More importantly, the 7900A is supported on most versions of TimeShared BASIC, including the "E" version which only needs one cpu. Regards, Jay West