On 8/12/19 8:16 AM, Nigel Johnson via cctalk wrote: > Another consideration with the TC02 is the small buffer. I don't know > what tape speed your drive runs at, but we lost a lot of sales to Dilog > because of buffer overflow on some of the faster CDC dirves. When we > came out with the TC03, it had a larger buffer to handle this.
The Qualstar drive is a *slow* drive. 50 ips in 1600 PE mode and a whopping 12.5 IPS in 6250 GCR mode. Transfer rate in either is about 80KB/sec. Qualstar doesn't have a mechanical buffer (spring arms or vacuum column) like most drives; it's all handled by the reel servos. It's wonder that it works at all. I doubt that it will overwhelm a PDP11. It probably doesn't overwhelm an IBM PC XT. The SCSI version of the drive does have a 256KB buffer, but I'm uncertain what the Pertec interface model has. --Chuck