mark0x01
Experienced Member
Finally, after months of frustration, I have a booting Televideo TS 803.
The system eprom, FD1793 FD controller and SY6545 CRT controller were all faulty.
I had a "loan" 1793 from an S100 card, but nothing else using a 6545 to borrow, so a long wait from ebay.
The 6545 was outputing horizontal sync at about 4 times the usual frequency (about 64Khz), which did very strange things to the video.
The horizontal oscillator design, with a 555 timer, doesn't free run without the sync signal.
It is currently booting from a Gotek HXC Floppy Emulator.
The Gotek is setup for standard Shugart mode, and is booting the 803_CPM_v1.5.IMD which I converted to hfe using HxCFloppyEmulator (running on Linux under Wine)
I also tried the "803_Turbodos_Boot.IMD", but it was not running properly, so I'll need to find out why.
The final hurdle is to get the two floppy drives, both Teac FD-55B-01-U working properly.
They did test as ok on a PC previously, but under CPM, a floppy format fails in the higher tracks.
It could be media issues or dirty heads, so will need to work on that next.
I have a few used DSDD floppies, and I also need to locate my spare floppy drive collection.
Cosmetically, the plastic case has darkened considerably, and the previous owner engraved their details all over the place, so it will need some serious work to look good.
The keyboard case is the same, but other than a few jamming keycaps, seems to work well.
I'll tackle the cosmetic refurbishment once it is fully working.
I'm also looking at building a greasewezel clone that can double as a stand alone floppy drive tester.
The system eprom, FD1793 FD controller and SY6545 CRT controller were all faulty.
I had a "loan" 1793 from an S100 card, but nothing else using a 6545 to borrow, so a long wait from ebay.
The 6545 was outputing horizontal sync at about 4 times the usual frequency (about 64Khz), which did very strange things to the video.
The horizontal oscillator design, with a 555 timer, doesn't free run without the sync signal.
It is currently booting from a Gotek HXC Floppy Emulator.
The Gotek is setup for standard Shugart mode, and is booting the 803_CPM_v1.5.IMD which I converted to hfe using HxCFloppyEmulator (running on Linux under Wine)
I also tried the "803_Turbodos_Boot.IMD", but it was not running properly, so I'll need to find out why.
The final hurdle is to get the two floppy drives, both Teac FD-55B-01-U working properly.
They did test as ok on a PC previously, but under CPM, a floppy format fails in the higher tracks.
It could be media issues or dirty heads, so will need to work on that next.
I have a few used DSDD floppies, and I also need to locate my spare floppy drive collection.
Cosmetically, the plastic case has darkened considerably, and the previous owner engraved their details all over the place, so it will need some serious work to look good.
The keyboard case is the same, but other than a few jamming keycaps, seems to work well.
I'll tackle the cosmetic refurbishment once it is fully working.
I'm also looking at building a greasewezel clone that can double as a stand alone floppy drive tester.
