I got in contact with one of the original developers SCAMP!!
He confirmed, the SCAMP prototype did use a Norelco (Phlips) “carry-corder” (a consumer tape recorder from a few years earlier). This is also mentioned in a 1983 PC Magazine article by Friedl, and that article has a photo of SCAMP opened (the only image of that I’ve ever found). And, this contact said that indeed that “carry-corder” did work but was so unreliable, during demos of the prototype – they’d have to attempt reloading the software many times. So, once it finally loaded correctly, they’d just leave the machine on overnight to be ready for the demo the next day. Keep in mind, that’s the 1973 prototype. The 1975 production used a 3M QIC (DC300), completely different tape system (that 300ft of tape could only store up to 207KB max - but within a few years after 1975, you could get longer tapes that fit in the same package).
Wanted to broadcast a couple interesting updates related to the IBM5100/5110 for 2024…
#1) Around February, Christian Corti revealed an original IBM 5100 software called SPACEWAR. Corti then updated the code to work appropriately on an IBM 5110. I then used my “serial keyboard” adapter to “fast-type” the raw machine code into my IBM 5110, and save a copy to tape. Here is a demo of what that original software looks like:
#2) A working emulator of the IBM 5100 and 5110 is now available as part of MAME! This was an amazing development - while we had a working 5110 emulator for awhile, there was an addressing-challenge in getting the IBM 5100 version of the emulator to work (despite both systems using the same PALM processor). It is now part of the official MAME builds. Storage support (tape or disk) is still not quite there, but it does otherwise run the original BASIC and APL ROMs and Executive ROS software. I did a write up on using this emulator here:
After nearly two years of study — off and on, at weekends – I’ve felt comfortable enough with the PALM instruction set to attempt my own application. And since the IBM 5100 allows daisy chaining a few monitors together, I’ve always wanted to do a “horizontal side scroll” type demo.
Later in the summer as I get time, I’ll make the code available and do a longer description about the design and how it works (and ways to do it better)
Indeed, after typing all the machine code in manually I was nervous on if the tape unit still worked - and luckily it did! (I hadn’t used it in about a year). Both WRITE and READ worked. This tape unit has no number counter like most of the audio cassette tape ones - you have to MARK the file slots, which really isn’t too much different than FAT (i.e. even if you create a 1-byte file, it still consumes an entire “allocation unit”). Initially I just had 2K MARKd files, and that would have been sufficient - but some last minute additions pushed my machine code to 2080 bytes (the half speed single line scroller at the bottom). So I had to MARK some additional 3K file slots at the end of the existing slots.
Anyway, just glad it all worked (both the software and hardware) !
Work in progress tech doc/notes on the scroller code (PDF, PPT, and a Excel summary of the PALM instructions)
Archive of sources, notes, and some tech docs explaining how the scroller code works (also PDF, PPT, and Excel summary of PALM instructions). For reference to anyone interested in the future.