When the XL7700 was launched in the late eighties Photoshop was in its infancy. All the serious players in the digital retouching and enhancement business were using bespoke systems based on Sun, Dec and Silicon Graphics platforms and, of course, there was also Quantel. PCs at that time had no hope of crunching the digits involved at any sensible speed, and MACs, always more popular with graphic artists, were only very slightly better. We had one image recorder (film writer) that required a DEC Microvax all to itself solely as the output device. Our own retouching systems were based on Sun 4/370 and 670MP pedestals and Sparc 10 and 20 desktops.
Any system comprising of a Howtek flat bed scanner and an XL7700 printer would have been relatively low end. It would explain the tape drive for IO, as film scans, or any higher res inputs, could well have been farmed out to a scanning house and any higher res, larger output sent to a company with suitable film writing or printing facilities. It may well have been PC or MAC based, but MAC is more likely.
Photoshop wouldn’t have cared less about the tape drive – that would just have been used at operating system level, probably with some other utility program, to get the files in and out of the host system. I would think that, being SCSI, an Adaptec card and ASPI drivers would be all that were needed for the OS to see the drive, and then either a standalone, or part of a larger app, utility that understood the particular command set required. The following links “may” be of help -
https://winworldpc.com/product/adaptec-ez-scsi/1x
https://www.curiousmarc.com/computin...and-tape-drive
http://www.dbit.com/pub/ibmpc/util/ <- st.exe and st.txt
The XL7700 was used across many markets, military, medical, newspaper publishers, graphic arts, professional photography etc. It was originally used by the US Air Force on board AWACS, hence the rack mounting. In a later guise, based on the updated XLT7720, it was also used to produce the index prints that were inserted into the front of the jewel cases of Photo CDs.
It will probably be an uphill struggle to resurrect an XL7700 now. For one thing, the media has been discontinued for it for many years and there was never a “compatible” equivalent manufactured. If you have some media for it that may be all you can get. There was a Photoshop Export Module, as well as Windows and MAC drivers, but they were all sold separately and were very expensive. You may struggle to find a copy of these now. Finally, the printer itself contains a 386DX based industrial single board computer as a CPU. It has, depending on version, either a back-up battery or an NVRAM chip with internal battery that will almost certainly be dead now. As an aside, internal memory is 12MB – huge at the time!
Each printer came with a floppy disk containing the specific calibration data related to the hardware (thermal head, primarily) fitted to that serial number. There was a calibration utility program to re-generate it if required (called Tablemaker if my memory is correct), but as well as that you would also need a Densitometer such as, at the time, the X-Rite 810 to complete the process.
I have some service data for the printer and have attached the diagram package and error code listing PDFs, should they be of any help. I’ve probably got more if I dig.