glitch
Veteran Member
This is the Pegasus Data Systems Pegasus II:
It's a big old S-100 turnkey box. I picked this one up from Doug Crawford in December 2019, fixed it in June 2020, and just now got around to writing it up:
I'd actually worked on this computer when Doug first got it, he brought it to a VCFed repair workshop. It had this weird problem where it would boot from diskette fine, but would frag diskettes on any kind of write. It uses a National Multiplex D4S controller, which is similar to (but not compatible with) the VersaFloppy II. National Multiplex did kinda junk boards, and they were using a 75492 LED driver that TI designed for calculators to drive some of the floppy signals, including data write! This ended up being the problem, the 75492 was failing somehow and was responsible for clobbering diskettes. I ended up adapting a 7405 open collector hex inverter to replace the 75492.
Anyone know anything about Pegasus Data Systems? This seems to be a very "Garden State" computer: Pegasus were themselves in NJ, so was National Multiplex, and Electronic Control Technology, who made the S-100 backplane. They used the TDL ZASM, another NJ company. Hugh Turner, the previous owner of this system, lived in NJ and apparently did programming and integration work for Pegasus and/or National Multiplex.
It's a big old S-100 turnkey box. I picked this one up from Doug Crawford in December 2019, fixed it in June 2020, and just now got around to writing it up:
I'd actually worked on this computer when Doug first got it, he brought it to a VCFed repair workshop. It had this weird problem where it would boot from diskette fine, but would frag diskettes on any kind of write. It uses a National Multiplex D4S controller, which is similar to (but not compatible with) the VersaFloppy II. National Multiplex did kinda junk boards, and they were using a 75492 LED driver that TI designed for calculators to drive some of the floppy signals, including data write! This ended up being the problem, the 75492 was failing somehow and was responsible for clobbering diskettes. I ended up adapting a 7405 open collector hex inverter to replace the 75492.
Anyone know anything about Pegasus Data Systems? This seems to be a very "Garden State" computer: Pegasus were themselves in NJ, so was National Multiplex, and Electronic Control Technology, who made the S-100 backplane. They used the TDL ZASM, another NJ company. Hugh Turner, the previous owner of this system, lived in NJ and apparently did programming and integration work for Pegasus and/or National Multiplex.