Search found 1557 matches
- Mon May 06, 2019 8:50 pm
- Forum: Hardware
- Topic: TS 1000 artifacts after warming up
- Replies: 14
- Views: 2610
Re: TS 1000 artifacts after warming up
Hi Again, yesterday i soak tested a ULA for over 3 hours and all is well it is been packed up now ready to wing its way over to you. the commodore monitors work fine but do need the link on the ula shorting as they have a high impedance input on that composite input. from the scope trace it does loo...
- Mon Apr 22, 2019 12:13 am
- Forum: Hardware
- Topic: Composite mod done Zx81 great picture but somethkng is wrong
- Replies: 14
- Views: 3071
Re: Composite mod done Zx81 great picture but somethkng is wrong
unless you really need the capacitor i'd ditch it... most modern tv's don't have any DC bias on the composite inputs.
regards Andy
regards Andy
- Sun Apr 21, 2019 1:36 pm
- Forum: Hardware
- Topic: Composite mod done Zx81 great picture but somethkng is wrong
- Replies: 14
- Views: 3071
Re: Composite mod done Zx81 great picture but somethkng is wrong
Don't let Moggy know but try a heatsink on the ULA...
BTW which composite mod did you do?
Andy
BTW which composite mod did you do?
Andy
- Sun Apr 21, 2019 1:38 am
- Forum: Welcome Area
- Topic: Hello all from Wellington, New Zealand
- Replies: 3
- Views: 1548
Re: Hello all from Wellington, New Zealand
Welcome, hope you find some useful information.
Regards Andy
Regards Andy
- Sat Apr 13, 2019 3:04 pm
- Forum: Hardware
- Topic: ZX81 External Keyboard
- Replies: 38
- Views: 11214
Re: ZX81 External Keyboard
Hi
is this keyboard available yet ?
regards Andy
is this keyboard available yet ?
regards Andy
- Fri Apr 12, 2019 10:37 pm
- Forum: Hardware
- Topic: Overclocking the machine
- Replies: 3
- Views: 1212
Re: Overclocking the machine
Andy (a member here) has seriously overclocked a ZX81. However he was using his older ULA replacement module. With a standard Sinclair ULA, overclocking is difficult as you can’t change the frequency without messing up the screen display. Mark Slight correction, the older ULA could do 2X speed... m...
- Mon Apr 01, 2019 7:07 pm
- Forum: Hardware
- Topic: TS1500 50Hz which resistor
- Replies: 6
- Views: 1440
- Sun Mar 31, 2019 10:18 pm
- Forum: ZX BASIC
- Topic: what is the largest number that can be stored on a zx81
- Replies: 10
- Views: 4332
Re: what is the largest number that can be stored on a zx81
lets assume we are going to use the whole 16K to store a single whole number dont want ony of the rounding loss business with floating piont numbers and exponents ( although the number you could store would be huge ) so we have 16384 * 8 bits to store our large integer (2^0 + 2^1 + 2^2 .... + 2^1310...
- Sun Mar 31, 2019 10:04 pm
- Forum: Hardware
- Topic: TS1500 50Hz which resistor
- Replies: 6
- Views: 1440
Re: TS1500 50Hz which resistor
Not certain it can be done that way, least i never was able on my ts1500, however you can use and external rom and hardcode it for 50hz
regards Andy
regards Andy
- Thu Mar 14, 2019 5:58 pm
- Forum: Hardware
- Topic: Hello All & Dead ZX .. probably
- Replies: 16
- Views: 3437