After the fun with my T102 I decided to continue the fun with a busted T200 off eBay. After a complete re-cap, fixing lots of keyboard traces, huge mounts of cleaning I now have a nice functional T200! This unit came with the RAM fully populated and an EME ROM, which doesn't seem to do anything, calling 63012 locks is up, and 63013 returns OK with nothing else obvious. No NiCad or Y2K mods yet cause I ran out of parts, waiting on Digikey.
Well I got bored waiting on Digikey and thought, how fast can this thing go, so I swapped the 4.9151 crystal with a 10Mhz (all I had in-stock), and it boots and runs! So I quickly threw this program together, prime number example I found online modded to time the loop: 1 POWER CONT 10 CLS 20 PRINT "LIMIT"; 30 INPUT L 31 HH$ = LEFT$(TIME$,2) 32 MM$ = MID$(TIME$,4,2) 33 SS$ = RIGHT$(TIME$,2) 37 SEC = VAL(SS$) + (VAL(MM$) * 60) + (VAL(HH$) * 3600) 40 FOR N = 3 TO L 50 FOR D = 2 TO (N-1) 60 IF N/D=INT(N/D) THEN GOTO 100 70 NEXT D 80 PRINT N; 90 GOTO 110 100 PRINT "."; 110 NEXT N 111 HH$ = LEFT$(TIME$,2) 112 MM$ = MID$(TIME$,4,2) 113 SS$ = RIGHT$(TIME$,2) 114 SECE = (VAL(SS$) + (VAL(MM$) * 60) + (VAL(HH$) * 3600) - SEC) 117 PRINT "Duration = "; SECE ; " Seconds" 120 END Duration factory = 43sec, duration overclocked = 21sec! (with an input of 100) It isn't completely stable, sometimes I have to power it on 2-3 times, but once on it doesn't seem to have any trouble, aside from the clock resetting on occasion. I've not yet studied the schematic to determine if it's because 10Mhz isn't a multiple of the factory 4.9152, or because it's simply too fast to read properly, but I'll figure it out. I ran the above to 1000 a few times without issue or any lock ups. File transfer even works if I set my PC to 2400bps and the T200 to 1200. Overclocked comes at a 20mA over stock hit. Fun fun, happy Friday. BR, Andy
